docs: about AI-assisted contributions (#7464)

Signed-off-by: Ruihang Xia <waynestxia@gmail.com>

.github/actions/setup-greptimedb-cluster/action.yml

@@ -51,7 +51,7 @@ runs:
     run: |
       helm upgrade \
         --install my-greptimedb \
-        --set meta.backendStorage.etcd.endpoints=${{ inputs.etcd-endpoints }} \
+        --set 'meta.backendStorage.etcd.endpoints[0]=${{ inputs.etcd-endpoints }}' \
         --set meta.enableRegionFailover=${{ inputs.enable-region-failover }} \
         --set image.registry=${{ inputs.image-registry }} \
         --set image.repository=${{ inputs.image-repository }}  \

.github/scripts/create-version.sh

@@ -49,6 +49,17 @@ function create_version() {
       echo "GITHUB_REF_NAME is empty in push event" >&2
       exit 1
     fi
+    
+    # For tag releases, ensure GITHUB_REF_NAME matches the version in Cargo.toml
+    CARGO_VERSION=$(grep '^version = ' Cargo.toml | cut -d '"' -f 2 | head -n 1)
+    EXPECTED_REF_NAME="v${CARGO_VERSION}"
+    
+    if [ "$GITHUB_REF_NAME" != "$EXPECTED_REF_NAME" ]; then
+      echo "Error: GITHUB_REF_NAME '$GITHUB_REF_NAME' does not match Cargo.toml version 'v${CARGO_VERSION}'" >&2
+      echo "Expected tag name: '$EXPECTED_REF_NAME'" >&2
+      exit 1
+    fi
+    
     echo "$GITHUB_REF_NAME"
   elif [ "$GITHUB_EVENT_NAME" = workflow_dispatch ]; then
     echo "$NEXT_RELEASE_VERSION-$(git rev-parse --short HEAD)-$(date "+%Y%m%d-%s")"

.github/scripts/deploy-greptimedb.sh

@@ -81,7 +81,7 @@ function deploy_greptimedb_cluster() {
     --create-namespace \
     --set image.tag="$GREPTIMEDB_IMAGE_TAG" \
     --set initializer.tag="$GREPTIMEDB_INITIALIZER_IMAGE_TAG" \
-    --set meta.backendStorage.etcd.endpoints="etcd.$install_namespace:2379" \
+    --set "meta.backendStorage.etcd.endpoints[0]=etcd.$install_namespace.svc.cluster.local:2379" \
     --set meta.backendStorage.etcd.storeKeyPrefix="$cluster_name" \
     -n "$install_namespace"
 
@@ -119,7 +119,7 @@ function deploy_greptimedb_cluster_with_s3_storage() {
     --create-namespace \
     --set image.tag="$GREPTIMEDB_IMAGE_TAG" \
     --set initializer.tag="$GREPTIMEDB_INITIALIZER_IMAGE_TAG" \
-    --set meta.backendStorage.etcd.endpoints="etcd.$install_namespace:2379" \
+    --set "meta.backendStorage.etcd.endpoints[0]=etcd.$install_namespace.svc.cluster.local:2379" \
     --set meta.backendStorage.etcd.storeKeyPrefix="$cluster_name" \
     --set objectStorage.s3.bucket="$AWS_CI_TEST_BUCKET" \
     --set objectStorage.s3.region="$AWS_REGION" \

.github/workflows/check-git-deps.yml

@@ -0,0 +1,154 @@
+name: Check Git Dependencies on Main Branch
+
+on:
+    pull_request:
+        branches: [main]
+        paths:
+            - 'Cargo.toml'
+    push:
+        branches: [main]
+        paths:
+            - 'Cargo.toml'
+
+jobs:
+    check-git-deps:
+        runs-on: ubuntu-latest
+
+        steps:
+            - name: Checkout repository
+              uses: actions/checkout@v6
+
+            - name: Check git dependencies
+              env:
+                  WHITELIST_DEPS: "greptime-proto,meter-core,meter-macros"
+              run: |
+                  #!/bin/bash
+                  set -e
+
+                  echo "Checking whitelisted git dependencies..."
+
+                  # Function to check if a commit is on main branch
+                  check_commit_on_main() {
+                      local repo_url="$1"
+                      local commit="$2"
+                      local repo_name=$(basename "$repo_url" .git)
+
+                      echo "Checking $repo_name"
+                      echo "Repo: $repo_url"
+                      echo "Commit: $commit"
+
+                      # Create a temporary directory for cloning
+                      local temp_dir=$(mktemp -d)
+
+                      # Clone the repository
+                      if git clone "$repo_url" "$temp_dir" 2>/dev/null; then
+                          cd "$temp_dir"
+
+                          # Try to determine the main branch name
+                          local main_branch="main"
+                          if ! git rev-parse --verify origin/main >/dev/null 2>&1; then
+                              if git rev-parse --verify origin/master >/dev/null 2>&1; then
+                                  main_branch="master"
+                              else
+                                  # Try to get the default branch
+                                  main_branch=$(git symbolic-ref refs/remotes/origin/HEAD | sed 's@^refs/remotes/origin/@@')
+                              fi
+                          fi
+
+                          echo "Main branch: $main_branch"
+
+                          # Check if commit exists
+                          if git cat-file -e "$commit" 2>/dev/null; then
+                              # Check if commit is on main branch
+                              if git merge-base --is-ancestor "$commit" "origin/$main_branch" 2>/dev/null; then
+                                  echo "PASS: Commit $commit is on $main_branch branch"
+                                  cd - >/dev/null
+                                  rm -rf "$temp_dir"
+                                  return 0
+                              else
+                                  echo "FAIL: Commit $commit is NOT on $main_branch branch"
+
+                                  # Try to find which branch contains this commit
+                                  local branch_name=$(git branch -r --contains "$commit" 2>/dev/null | head -1 | sed 's/^[[:space:]]*origin\///' | sed 's/[[:space:]]*$//')
+                                  if [[ -n "$branch_name" ]]; then
+                                      echo "Found on branch: $branch_name"
+                                  fi
+                                  cd - >/dev/null
+                                  rm -rf "$temp_dir"
+                                  return 1
+                              fi
+                          else
+                              echo "FAIL: Commit $commit not found in repository"
+                              cd - >/dev/null
+                              rm -rf "$temp_dir"
+                              return 1
+                          fi
+                      else
+                          echo "FAIL: Failed to clone $repo_url"
+                          rm -rf "$temp_dir"
+                          return 1
+                      fi
+                  }
+
+                  # Extract whitelisted git dependencies from Cargo.toml
+                  echo "Extracting git dependencies from Cargo.toml..."
+
+                  # Create temporary array to store dependencies
+                  declare -a deps=()
+
+                  # Build awk pattern from whitelist
+                  IFS=',' read -ra WHITELIST <<< "$WHITELIST_DEPS"
+                  awk_pattern=""
+                  for dep in "${WHITELIST[@]}"; do
+                      if [[ -n "$awk_pattern" ]]; then
+                          awk_pattern="$awk_pattern|"
+                      fi
+                      awk_pattern="$awk_pattern$dep"
+                  done
+
+                  # Extract whitelisted dependencies
+                  while IFS= read -r line; do
+                      if [[ -n "$line" ]]; then
+                          deps+=("$line")
+                      fi
+                  done < <(awk -v pattern="$awk_pattern" '
+                  $0 ~ pattern ".*git = \"https:/" {
+                      match($0, /git = "([^"]+)"/, arr)
+                      git_url = arr[1]
+                      if (match($0, /rev = "([^"]+)"/, rev_arr)) {
+                          rev = rev_arr[1]
+                          print git_url " " rev
+                      } else {
+                          # Check next line for rev
+                          getline
+                          if (match($0, /rev = "([^"]+)"/, rev_arr)) {
+                              rev = rev_arr[1]
+                              print git_url " " rev
+                          }
+                      }
+                  }
+                  ' Cargo.toml)
+
+                  echo "Found ${#deps[@]} dependencies to check:"
+                  for dep in "${deps[@]}"; do
+                      echo "  $dep"
+                  done
+
+                  failed=0
+
+                  for dep in "${deps[@]}"; do
+                      read -r repo_url commit <<< "$dep"
+                      if ! check_commit_on_main "$repo_url" "$commit"; then
+                          failed=1
+                      fi
+                  done
+
+                  echo "Check completed."
+
+                  if [[ $failed -eq 1 ]]; then
+                      echo "ERROR: Some git dependencies are not on their main branches!"
+                      echo "Please update the commits to point to main branch commits."
+                      exit 1
+                  else
+                      echo "SUCCESS: All git dependencies are on their main branches!"
+                  fi

.github/workflows/release.yml

@@ -49,14 +49,9 @@ on:
         description: Do not run integration tests during the build
         type: boolean
         default: true
-      build_linux_amd64_artifacts:
+      build_linux_artifacts:
         type: boolean
-        description: Build linux-amd64 artifacts
-        required: false
-        default: false
-      build_linux_arm64_artifacts:
-        type: boolean
-        description: Build linux-arm64 artifacts
+        description: Build linux artifacts (both amd64 and arm64)
         required: false
         default: false
       build_macos_artifacts:
@@ -144,7 +139,7 @@ jobs:
           ./.github/scripts/check-version.sh "${{ steps.create-version.outputs.version }}"
 
       - name: Allocate linux-amd64 runner
-        if: ${{ inputs.build_linux_amd64_artifacts || github.event_name == 'push' || github.event_name == 'schedule' }}
+        if: ${{ inputs.build_linux_artifacts || github.event_name == 'push' || github.event_name == 'schedule' }}
         uses: ./.github/actions/start-runner
         id: start-linux-amd64-runner
         with:
@@ -158,7 +153,7 @@ jobs:
           subnet-id: ${{ vars.EC2_RUNNER_SUBNET_ID }}
 
       - name: Allocate linux-arm64 runner
-        if: ${{ inputs.build_linux_arm64_artifacts || github.event_name == 'push' || github.event_name == 'schedule' }}
+        if: ${{ inputs.build_linux_artifacts || github.event_name == 'push' || github.event_name == 'schedule' }}
         uses: ./.github/actions/start-runner
         id: start-linux-arm64-runner
         with:
@@ -173,7 +168,7 @@ jobs:
 
   build-linux-amd64-artifacts:
     name: Build linux-amd64 artifacts
-    if: ${{ inputs.build_linux_amd64_artifacts || github.event_name == 'push' || github.event_name == 'schedule' }}
+    if: ${{ inputs.build_linux_artifacts || github.event_name == 'push' || github.event_name == 'schedule' }}
     needs: [
       allocate-runners,
     ]
@@ -195,7 +190,7 @@ jobs:
 
   build-linux-arm64-artifacts:
     name: Build linux-arm64 artifacts
-    if: ${{ inputs.build_linux_arm64_artifacts || github.event_name == 'push' || github.event_name == 'schedule' }}
+    if: ${{ inputs.build_linux_artifacts || github.event_name == 'push' || github.event_name == 'schedule' }}
     needs: [
       allocate-runners,
     ]
@@ -217,7 +212,7 @@ jobs:
 
   run-multi-lang-tests:
     name: Run Multi-language SDK Tests
-    if: ${{ inputs.build_linux_amd64_artifacts || github.event_name == 'push' || github.event_name == 'schedule' }}
+    if: ${{ inputs.build_linux_artifacts || github.event_name == 'push' || github.event_name == 'schedule' }}
     needs: [
       allocate-runners,
       build-linux-amd64-artifacts,
@@ -386,7 +381,18 @@ jobs:
 
   publish-github-release:
     name: Create GitHub release and upload artifacts
-    if: ${{ inputs.publish_github_release || github.event_name == 'push' || github.event_name == 'schedule' }}
+    # Use always() to run even when optional jobs (macos, windows) are skipped.
+    # Then check that required jobs succeeded and optional jobs didn't fail.
+    if: |
+      always() &&
+      (inputs.publish_github_release || github.event_name == 'push' || github.event_name == 'schedule') &&
+      needs.allocate-runners.result == 'success' &&
+      (needs.build-linux-amd64-artifacts.result == 'success' || needs.build-linux-amd64-artifacts.result == 'skipped') &&
+      (needs.build-linux-arm64-artifacts.result == 'success' || needs.build-linux-arm64-artifacts.result == 'skipped') &&
+      (needs.build-macos-artifacts.result == 'success' || needs.build-macos-artifacts.result == 'skipped') &&
+      (needs.build-windows-artifacts.result == 'success' || needs.build-windows-artifacts.result == 'skipped') &&
+      (needs.release-images-to-dockerhub.result == 'success' || needs.release-images-to-dockerhub.result == 'skipped') &&
+      (needs.run-multi-lang-tests.result == 'success' || needs.run-multi-lang-tests.result == 'skipped')
     needs: [ # The job have to wait for all the artifacts are built.
       allocate-runners,
       build-linux-amd64-artifacts,

CONTRIBUTING.md

@@ -102,6 +102,30 @@ like `feat`/`fix`/`docs`, with a concise summary of code change following. AVOID
 
 All commit messages SHOULD adhere to the [Conventional Commits specification](https://conventionalcommits.org/).
 
+## AI-Assisted contributions
+
+We has the following policy for AI-assisted PRs:
+
+- The PR author should **understand the core ideas** behind the implementation **end-to-end**, and be able to justify the design and code during review.
+- **Calls out unknowns and assumptions**. It's okay to not fully understand some bits of AI generated code. You should comment on these cases and point them out to reviewers so that they can use their knowledge of the codebase to clear up any concerns. For example, you might comment "calling this function here seems to work but I'm not familiar with how it works internally, I wonder if there's a race condition if it is called concurrently".
+
+### Why fully AI-generated PRs without understanding are not helpful
+
+Today, AI tools cannot reliably make complex changes to DataFusion on their own, which is why we rely on pull requests and code review.
+
+The purposes of code review are:
+
+1. Finish the intended task.
+2. Share knowledge between authors and reviewers, as a long-term investment in the project. For this reason, even if someone familiar with the codebase can finish a task quickly, we're still happy to help a new contributor work on it even if it takes longer.
+
+An AI dump for an issue doesn’t meet these purposes. Maintainers could finish the task faster by using AI directly, and the submitters gain little knowledge if they act only as a pass through AI proxy without understanding.
+
+Please understand the reviewing capacity is **very limited** for the project, so large PRs which appear to not have the requisite understanding might not get reviewed, and eventually closed or redirected.
+
+### Better ways to contribute than an “AI dump”
+
+It's recommended to write a high-quality issue with a clear problem statement and a minimal, reproducible example. This can make it easier for others to contribute.
+
 ## Getting Help
 
 There are many ways to get help when you're stuck. It is recommended to ask for help by opening an issue, with a detailed description

Cargo.toml

@@ -21,6 +21,7 @@ members = [
     "src/common/grpc-expr",
     "src/common/macro",
     "src/common/mem-prof",
+    "src/common/memory-manager",
     "src/common/meta",
     "src/common/options",
     "src/common/plugins",
@@ -74,7 +75,7 @@ members = [
 resolver = "2"
 
 [workspace.package]
-version = "1.0.0-beta.2"
+version = "1.0.0-beta.3"
 edition = "2024"
 license = "Apache-2.0"
 
@@ -131,7 +132,7 @@ datafusion-functions = "50"
 datafusion-functions-aggregate-common = "50"
 datafusion-optimizer = "50"
 datafusion-orc = "0.5"
-datafusion-pg-catalog = "0.12.2"
+datafusion-pg-catalog = "0.12.3"
 datafusion-physical-expr = "50"
 datafusion-physical-plan = "50"
 datafusion-sql = "50"
@@ -139,16 +140,17 @@ datafusion-substrait = "50"
 deadpool = "0.12"
 deadpool-postgres = "0.14"
 derive_builder = "0.20"
+derive_more = { version = "2.1", features = ["full"] }
 dotenv = "0.15"
 either = "1.15"
-etcd-client = { git = "https://github.com/GreptimeTeam/etcd-client", rev = "f62df834f0cffda355eba96691fe1a9a332b75a7", features = [
+etcd-client = { version = "0.16.1", features = [
     "tls",
     "tls-roots",
 ] }
 fst = "0.4.7"
 futures = "0.3"
 futures-util = "0.3"
-greptime-proto = { git = "https://github.com/GreptimeTeam/greptime-proto.git", rev = "0df99f09f1d6785055b2d9da96fc4ecc2bdf6803" }
+greptime-proto = { git = "https://github.com/GreptimeTeam/greptime-proto.git", rev = "173efe5ec62722089db7c531c0b0d470a072b915" }
 hex = "0.4"
 http = "1"
 humantime = "2.1"
@@ -200,7 +202,8 @@ reqwest = { version = "0.12", default-features = false, features = [
     "stream",
     "multipart",
 ] }
-rskafka = { git = "https://github.com/WenyXu/rskafka.git", rev = "7b0f31ed39db049b4ee2e5f1e95b5a30be9baf76", features = [
+# Branch: feat/request-timeout
+rskafka = { git = "https://github.com/GreptimeTeam/rskafka.git", rev = "f5688f83e7da591cda3f2674c2408b4c0ed4ed50", features = [
     "transport-tls",
 ] }
 rstest = "0.25"
@@ -264,6 +267,7 @@ common-grpc = { path = "src/common/grpc" }
 common-grpc-expr = { path = "src/common/grpc-expr" }
 common-macro = { path = "src/common/macro" }
 common-mem-prof = { path = "src/common/mem-prof" }
+common-memory-manager = { path = "src/common/memory-manager" }
 common-meta = { path = "src/common/meta" }
 common-options = { path = "src/common/options" }
 common-plugins = { path = "src/common/plugins" }

config/config.md

@@ -14,11 +14,12 @@
 | --- | -----| ------- | ----------- |
 | `default_timezone` | String | Unset | The default timezone of the server. |
 | `default_column_prefix` | String | Unset | The default column prefix for auto-created time index and value columns. |
+| `max_in_flight_write_bytes` | String | Unset | Maximum total memory for all concurrent write request bodies and messages (HTTP, gRPC, Flight).<br/>Set to 0 to disable the limit. Default: "0" (unlimited) |
+| `write_bytes_exhausted_policy` | String | Unset | Policy when write bytes quota is exhausted.<br/>Options: "wait" (default, 10s timeout), "wait(<duration>)" (e.g., "wait(30s)"), "fail" |
 | `init_regions_in_background` | Bool | `false` | Initialize all regions in the background during the startup.<br/>By default, it provides services after all regions have been initialized. |
 | `init_regions_parallelism` | Integer | `16` | Parallelism of initializing regions. |
 | `max_concurrent_queries` | Integer | `0` | The maximum current queries allowed to be executed. Zero means unlimited.<br/>NOTE: This setting affects scan_memory_limit's privileged tier allocation.<br/>When set, 70% of queries get privileged memory access (full scan_memory_limit).<br/>The remaining 30% get standard tier access (70% of scan_memory_limit). |
 | `enable_telemetry` | Bool | `true` | Enable telemetry to collect anonymous usage data. Enabled by default. |
-| `max_in_flight_write_bytes` | String | Unset | The maximum in-flight write bytes. |
 | `runtime` | -- | -- | The runtime options. |
 | `runtime.global_rt_size` | Integer | `8` | The number of threads to execute the runtime for global read operations. |
 | `runtime.compact_rt_size` | Integer | `4` | The number of threads to execute the runtime for global write operations. |
@@ -26,14 +27,12 @@
 | `http.addr` | String | `127.0.0.1:4000` | The address to bind the HTTP server. |
 | `http.timeout` | String | `0s` | HTTP request timeout. Set to 0 to disable timeout. |
 | `http.body_limit` | String | `64MB` | HTTP request body limit.<br/>The following units are supported: `B`, `KB`, `KiB`, `MB`, `MiB`, `GB`, `GiB`, `TB`, `TiB`, `PB`, `PiB`.<br/>Set to 0 to disable limit. |
-| `http.max_total_body_memory` | String | Unset | Maximum total memory for all concurrent HTTP request bodies.<br/>Set to 0 to disable the limit. Default: "0" (unlimited) |
 | `http.enable_cors` | Bool | `true` | HTTP CORS support, it's turned on by default<br/>This allows browser to access http APIs without CORS restrictions |
 | `http.cors_allowed_origins` | Array | Unset | Customize allowed origins for HTTP CORS. |
 | `http.prom_validation_mode` | String | `strict` | Whether to enable validation for Prometheus remote write requests.<br/>Available options:<br/>- strict: deny invalid UTF-8 strings (default).<br/>- lossy: allow invalid UTF-8 strings, replace invalid characters with REPLACEMENT_CHARACTER(U+FFFD).<br/>- unchecked: do not valid strings. |
 | `grpc` | -- | -- | The gRPC server options. |
 | `grpc.bind_addr` | String | `127.0.0.1:4001` | The address to bind the gRPC server. |
 | `grpc.runtime_size` | Integer | `8` | The number of server worker threads. |
-| `grpc.max_total_message_memory` | String | Unset | Maximum total memory for all concurrent gRPC request messages.<br/>Set to 0 to disable the limit. Default: "0" (unlimited) |
 | `grpc.max_connection_age` | String | Unset | The maximum connection age for gRPC connection.<br/>The value can be a human-readable time string. For example: `10m` for ten minutes or `1h` for one hour.<br/>Refer to https://grpc.io/docs/guides/keepalive/ for more details. |
 | `grpc.tls` | -- | -- | gRPC server TLS options, see `mysql.tls` section. |
 | `grpc.tls.mode` | String | `disable` | TLS mode. |
@@ -83,6 +82,8 @@
 | `wal.sync_period` | String | `10s` | Duration for fsyncing log files.<br/>**It's only used when the provider is `raft_engine`**. |
 | `wal.recovery_parallelism` | Integer | `2` | Parallelism during WAL recovery. |
 | `wal.broker_endpoints` | Array | -- | The Kafka broker endpoints.<br/>**It's only used when the provider is `kafka`**. |
+| `wal.connect_timeout` | String | `3s` | The connect timeout for kafka client.<br/>**It's only used when the provider is `kafka`**. |
+| `wal.timeout` | String | `3s` | The timeout for kafka client.<br/>**It's only used when the provider is `kafka`**. |
 | `wal.auto_create_topics` | Bool | `true` | Automatically create topics for WAL.<br/>Set to `true` to automatically create topics for WAL.<br/>Otherwise, use topics named `topic_name_prefix_[0..num_topics)` |
 | `wal.num_topics` | Integer | `64` | Number of topics.<br/>**It's only used when the provider is `kafka`**. |
 | `wal.selector_type` | String | `round_robin` | Topic selector type.<br/>Available selector types:<br/>- `round_robin` (default)<br/>**It's only used when the provider is `kafka`**. |
@@ -108,9 +109,6 @@
 | `storage` | -- | -- | The data storage options. |
 | `storage.data_home` | String | `./greptimedb_data` | The working home directory. |
 | `storage.type` | String | `File` | The storage type used to store the data.<br/>- `File`: the data is stored in the local file system.<br/>- `S3`: the data is stored in the S3 object storage.<br/>- `Gcs`: the data is stored in the Google Cloud Storage.<br/>- `Azblob`: the data is stored in the Azure Blob Storage.<br/>- `Oss`: the data is stored in the Aliyun OSS. |
-| `storage.enable_read_cache` | Bool | `true` | Whether to enable read cache. If not set, the read cache will be enabled by default when using object storage. |
-| `storage.cache_path` | String | Unset | Read cache configuration for object storage such as 'S3' etc, it's configured by default when using object storage. It is recommended to configure it when using object storage for better performance.<br/>A local file directory, defaults to `{data_home}`. An empty string means disabling. |
-| `storage.cache_capacity` | String | Unset | The local file cache capacity in bytes. If your disk space is sufficient, it is recommended to set it larger. |
 | `storage.bucket` | String | Unset | The S3 bucket name.<br/>**It's only used when the storage type is `S3`, `Oss` and `Gcs`**. |
 | `storage.root` | String | Unset | The S3 data will be stored in the specified prefix, for example, `s3://${bucket}/${root}`.<br/>**It's only used when the storage type is `S3`, `Oss` and `Azblob`**. |
 | `storage.access_key_id` | String | Unset | The access key id of the aws account.<br/>It's **highly recommended** to use AWS IAM roles instead of hardcoding the access key id and secret key.<br/>**It's only used when the storage type is `S3` and `Oss`**. |
@@ -141,6 +139,8 @@
 | `region_engine.mito.max_background_flushes` | Integer | Auto | Max number of running background flush jobs (default: 1/2 of cpu cores). |
 | `region_engine.mito.max_background_compactions` | Integer | Auto | Max number of running background compaction jobs (default: 1/4 of cpu cores). |
 | `region_engine.mito.max_background_purges` | Integer | Auto | Max number of running background purge jobs (default: number of cpu cores). |
+| `region_engine.mito.experimental_compaction_memory_limit` | String | 0 | Memory budget for compaction tasks. Setting it to 0 or "unlimited" disables the limit. |
+| `region_engine.mito.experimental_compaction_on_exhausted` | String | wait | Behavior when compaction cannot acquire memory from the budget.<br/>Options: "wait" (default, 10s), "wait(<duration>)", "fail" |
 | `region_engine.mito.auto_flush_interval` | String | `1h` | Interval to auto flush a region if it has not flushed yet. |
 | `region_engine.mito.global_write_buffer_size` | String | Auto | Global write buffer size for all regions. If not set, it's default to 1/8 of OS memory with a max limitation of 1GB. |
 | `region_engine.mito.global_write_buffer_reject_size` | String | Auto | Global write buffer size threshold to reject write requests. If not set, it's default to 2 times of `global_write_buffer_size`. |
@@ -154,6 +154,8 @@
 | `region_engine.mito.write_cache_ttl` | String | Unset | TTL for write cache. |
 | `region_engine.mito.preload_index_cache` | Bool | `true` | Preload index (puffin) files into cache on region open (default: true).<br/>When enabled, index files are loaded into the write cache during region initialization,<br/>which can improve query performance at the cost of longer startup times. |
 | `region_engine.mito.index_cache_percent` | Integer | `20` | Percentage of write cache capacity allocated for index (puffin) files (default: 20).<br/>The remaining capacity is used for data (parquet) files.<br/>Must be between 0 and 100 (exclusive). For example, with a 5GiB write cache and 20% allocation,<br/>1GiB is reserved for index files and 4GiB for data files. |
+| `region_engine.mito.enable_refill_cache_on_read` | Bool | `true` | Enable refilling cache on read operations (default: true).<br/>When disabled, cache refilling on read won't happen. |
+| `region_engine.mito.manifest_cache_size` | String | `256MB` | Capacity for manifest cache (default: 256MB). |
 | `region_engine.mito.sst_write_buffer_size` | String | `8MB` | Buffer size for SST writing. |
 | `region_engine.mito.parallel_scan_channel_size` | Integer | `32` | Capacity of the channel to send data from parallel scan tasks to the main task. |
 | `region_engine.mito.max_concurrent_scan_files` | Integer | `384` | Maximum number of SST files to scan concurrently. |
@@ -224,7 +226,8 @@
 | --- | -----| ------- | ----------- |
 | `default_timezone` | String | Unset | The default timezone of the server. |
 | `default_column_prefix` | String | Unset | The default column prefix for auto-created time index and value columns. |
-| `max_in_flight_write_bytes` | String | Unset | The maximum in-flight write bytes. |
+| `max_in_flight_write_bytes` | String | Unset | Maximum total memory for all concurrent write request bodies and messages (HTTP, gRPC, Flight).<br/>Set to 0 to disable the limit. Default: "0" (unlimited) |
+| `write_bytes_exhausted_policy` | String | Unset | Policy when write bytes quota is exhausted.<br/>Options: "wait" (default, 10s timeout), "wait(<duration>)" (e.g., "wait(30s)"), "fail" |
 | `runtime` | -- | -- | The runtime options. |
 | `runtime.global_rt_size` | Integer | `8` | The number of threads to execute the runtime for global read operations. |
 | `runtime.compact_rt_size` | Integer | `4` | The number of threads to execute the runtime for global write operations. |
@@ -235,7 +238,6 @@
 | `http.addr` | String | `127.0.0.1:4000` | The address to bind the HTTP server. |
 | `http.timeout` | String | `0s` | HTTP request timeout. Set to 0 to disable timeout. |
 | `http.body_limit` | String | `64MB` | HTTP request body limit.<br/>The following units are supported: `B`, `KB`, `KiB`, `MB`, `MiB`, `GB`, `GiB`, `TB`, `TiB`, `PB`, `PiB`.<br/>Set to 0 to disable limit. |
-| `http.max_total_body_memory` | String | Unset | Maximum total memory for all concurrent HTTP request bodies.<br/>Set to 0 to disable the limit. Default: "0" (unlimited) |
 | `http.enable_cors` | Bool | `true` | HTTP CORS support, it's turned on by default<br/>This allows browser to access http APIs without CORS restrictions |
 | `http.cors_allowed_origins` | Array | Unset | Customize allowed origins for HTTP CORS. |
 | `http.prom_validation_mode` | String | `strict` | Whether to enable validation for Prometheus remote write requests.<br/>Available options:<br/>- strict: deny invalid UTF-8 strings (default).<br/>- lossy: allow invalid UTF-8 strings, replace invalid characters with REPLACEMENT_CHARACTER(U+FFFD).<br/>- unchecked: do not valid strings. |
@@ -243,7 +245,6 @@
 | `grpc.bind_addr` | String | `127.0.0.1:4001` | The address to bind the gRPC server. |
 | `grpc.server_addr` | String | `127.0.0.1:4001` | The address advertised to the metasrv, and used for connections from outside the host.<br/>If left empty or unset, the server will automatically use the IP address of the first network interface<br/>on the host, with the same port number as the one specified in `grpc.bind_addr`. |
 | `grpc.runtime_size` | Integer | `8` | The number of server worker threads. |
-| `grpc.max_total_message_memory` | String | Unset | Maximum total memory for all concurrent gRPC request messages.<br/>Set to 0 to disable the limit. Default: "0" (unlimited) |
 | `grpc.flight_compression` | String | `arrow_ipc` | Compression mode for frontend side Arrow IPC service. Available options:<br/>- `none`: disable all compression<br/>- `transport`: only enable gRPC transport compression (zstd)<br/>- `arrow_ipc`: only enable Arrow IPC compression (lz4)<br/>- `all`: enable all compression.<br/>Default to `none` |
 | `grpc.max_connection_age` | String | Unset | The maximum connection age for gRPC connection.<br/>The value can be a human-readable time string. For example: `10m` for ten minutes or `1h` for one hour.<br/>Refer to https://grpc.io/docs/guides/keepalive/ for more details. |
 | `grpc.tls` | -- | -- | gRPC server TLS options, see `mysql.tls` section. |
@@ -343,14 +344,15 @@
 | `store_key_prefix` | String | `""` | If it's not empty, the metasrv will store all data with this key prefix. |
 | `backend` | String | `etcd_store` | The datastore for meta server.<br/>Available values:<br/>- `etcd_store` (default value)<br/>- `memory_store`<br/>- `postgres_store`<br/>- `mysql_store` |
 | `meta_table_name` | String | `greptime_metakv` | Table name in RDS to store metadata. Effect when using a RDS kvbackend.<br/>**Only used when backend is `postgres_store`.** |
-| `meta_schema_name` | String | `greptime_schema` | Optional PostgreSQL schema for metadata table and election table name qualification.<br/>When PostgreSQL public schema is not writable (e.g., PostgreSQL 15+ with restricted public),<br/>set this to a writable schema. GreptimeDB will use `meta_schema_name`.`meta_table_name`.<br/>GreptimeDB will NOT create the schema automatically; please ensure it exists or the user has permission.<br/>**Only used when backend is `postgres_store`.** |
+| `meta_schema_name` | String | `greptime_schema` | Optional PostgreSQL schema for metadata table and election table name qualification.<br/>When PostgreSQL public schema is not writable (e.g., PostgreSQL 15+ with restricted public),<br/>set this to a writable schema. GreptimeDB will use `meta_schema_name`.`meta_table_name`.<br/>**Only used when backend is `postgres_store`.** |
+| `auto_create_schema` | Bool | `true` | Automatically create PostgreSQL schema if it doesn't exist.<br/>When enabled, the system will execute `CREATE SCHEMA IF NOT EXISTS <schema_name>`<br/>before creating metadata tables. This is useful in production environments where<br/>manual schema creation may be restricted.<br/>Default is true.<br/>Note: The PostgreSQL user must have CREATE SCHEMA permission for this to work.<br/>**Only used when backend is `postgres_store`.** |
 | `meta_election_lock_id` | Integer | `1` | Advisory lock id in PostgreSQL for election. Effect when using PostgreSQL as kvbackend<br/>Only used when backend is `postgres_store`. |
 | `selector` | String | `round_robin` | Datanode selector type.<br/>- `round_robin` (default value)<br/>- `lease_based`<br/>- `load_based`<br/>For details, please see "https://docs.greptime.com/developer-guide/metasrv/selector". |
-| `use_memory_store` | Bool | `false` | Store data in memory. |
 | `enable_region_failover` | Bool | `false` | Whether to enable region failover.<br/>This feature is only available on GreptimeDB running on cluster mode and<br/>- Using Remote WAL<br/>- Using shared storage (e.g., s3). |
 | `region_failure_detector_initialization_delay` | String | `10m` | The delay before starting region failure detection.<br/>This delay helps prevent Metasrv from triggering unnecessary region failovers before all Datanodes are fully started.<br/>Especially useful when the cluster is not deployed with GreptimeDB Operator and maintenance mode is not enabled. |
 | `allow_region_failover_on_local_wal` | Bool | `false` | Whether to allow region failover on local WAL.<br/>**This option is not recommended to be set to true, because it may lead to data loss during failover.** |
 | `node_max_idle_time` | String | `24hours` | Max allowed idle time before removing node info from metasrv memory. |
+| `heartbeat_interval` | String | `3s` | Base heartbeat interval for calculating distributed time constants.<br/>The frontend heartbeat interval is 6 times of the base heartbeat interval.<br/>The flownode/datanode heartbeat interval is 1 times of the base heartbeat interval.<br/>e.g., If the base heartbeat interval is 3s, the frontend heartbeat interval is 18s, the flownode/datanode heartbeat interval is 3s.<br/>If you change this value, you need to change the heartbeat interval of the flownode/frontend/datanode accordingly. |
 | `enable_telemetry` | Bool | `true` | Whether to enable greptimedb telemetry. Enabled by default. |
 | `runtime` | -- | -- | The runtime options. |
 | `runtime.global_rt_size` | Integer | `8` | The number of threads to execute the runtime for global read operations. |
@@ -360,12 +362,18 @@
 | `backend_tls.cert_path` | String | `""` | Path to client certificate file (for client authentication)<br/>Like "/path/to/client.crt" |
 | `backend_tls.key_path` | String | `""` | Path to client private key file (for client authentication)<br/>Like "/path/to/client.key" |
 | `backend_tls.ca_cert_path` | String | `""` | Path to CA certificate file (for server certificate verification)<br/>Required when using custom CAs or self-signed certificates<br/>Leave empty to use system root certificates only<br/>Like "/path/to/ca.crt" |
+| `backend_client` | -- | -- | The backend client options.<br/>Currently, only applicable when using etcd as the metadata store. |
+| `backend_client.keep_alive_timeout` | String | `3s` | The keep alive timeout for backend client. |
+| `backend_client.keep_alive_interval` | String | `10s` | The keep alive interval for backend client. |
+| `backend_client.connect_timeout` | String | `3s` | The connect timeout for backend client. |
 | `grpc` | -- | -- | The gRPC server options. |
 | `grpc.bind_addr` | String | `127.0.0.1:3002` | The address to bind the gRPC server. |
 | `grpc.server_addr` | String | `127.0.0.1:3002` | The communication server address for the frontend and datanode to connect to metasrv.<br/>If left empty or unset, the server will automatically use the IP address of the first network interface<br/>on the host, with the same port number as the one specified in `bind_addr`. |
 | `grpc.runtime_size` | Integer | `8` | The number of server worker threads. |
 | `grpc.max_recv_message_size` | String | `512MB` | The maximum receive message size for gRPC server. |
 | `grpc.max_send_message_size` | String | `512MB` | The maximum send message size for gRPC server. |
+| `grpc.http2_keep_alive_interval` | String | `10s` | The server side HTTP/2 keep-alive interval |
+| `grpc.http2_keep_alive_timeout` | String | `3s` | The server side HTTP/2 keep-alive timeout. |
 | `http` | -- | -- | The HTTP server options. |
 | `http.addr` | String | `127.0.0.1:4000` | The address to bind the HTTP server. |
 | `http.timeout` | String | `0s` | HTTP request timeout. Set to 0 to disable timeout. |
@@ -475,6 +483,8 @@
 | `wal.sync_period` | String | `10s` | Duration for fsyncing log files.<br/>**It's only used when the provider is `raft_engine`**. |
 | `wal.recovery_parallelism` | Integer | `2` | Parallelism during WAL recovery. |
 | `wal.broker_endpoints` | Array | -- | The Kafka broker endpoints.<br/>**It's only used when the provider is `kafka`**. |
+| `wal.connect_timeout` | String | `3s` | The connect timeout for kafka client.<br/>**It's only used when the provider is `kafka`**. |
+| `wal.timeout` | String | `3s` | The timeout for kafka client.<br/>**It's only used when the provider is `kafka`**. |
 | `wal.max_batch_bytes` | String | `1MB` | The max size of a single producer batch.<br/>Warning: Kafka has a default limit of 1MB per message in a topic.<br/>**It's only used when the provider is `kafka`**. |
 | `wal.consumer_wait_timeout` | String | `100ms` | The consumer wait timeout.<br/>**It's only used when the provider is `kafka`**. |
 | `wal.create_index` | Bool | `true` | Whether to enable WAL index creation.<br/>**It's only used when the provider is `kafka`**. |
@@ -486,9 +496,6 @@
 | `storage` | -- | -- | The data storage options. |
 | `storage.data_home` | String | `./greptimedb_data` | The working home directory. |
 | `storage.type` | String | `File` | The storage type used to store the data.<br/>- `File`: the data is stored in the local file system.<br/>- `S3`: the data is stored in the S3 object storage.<br/>- `Gcs`: the data is stored in the Google Cloud Storage.<br/>- `Azblob`: the data is stored in the Azure Blob Storage.<br/>- `Oss`: the data is stored in the Aliyun OSS. |
-| `storage.cache_path` | String | Unset | Read cache configuration for object storage such as 'S3' etc, it's configured by default when using object storage. It is recommended to configure it when using object storage for better performance.<br/>A local file directory, defaults to `{data_home}`. An empty string means disabling. |
-| `storage.enable_read_cache` | Bool | `true` | Whether to enable read cache. If not set, the read cache will be enabled by default when using object storage. |
-| `storage.cache_capacity` | String | Unset | The local file cache capacity in bytes. If your disk space is sufficient, it is recommended to set it larger. |
 | `storage.bucket` | String | Unset | The S3 bucket name.<br/>**It's only used when the storage type is `S3`, `Oss` and `Gcs`**. |
 | `storage.root` | String | Unset | The S3 data will be stored in the specified prefix, for example, `s3://${bucket}/${root}`.<br/>**It's only used when the storage type is `S3`, `Oss` and `Azblob`**. |
 | `storage.access_key_id` | String | Unset | The access key id of the aws account.<br/>It's **highly recommended** to use AWS IAM roles instead of hardcoding the access key id and secret key.<br/>**It's only used when the storage type is `S3` and `Oss`**. |
@@ -521,6 +528,8 @@
 | `region_engine.mito.max_background_flushes` | Integer | Auto | Max number of running background flush jobs (default: 1/2 of cpu cores). |
 | `region_engine.mito.max_background_compactions` | Integer | Auto | Max number of running background compaction jobs (default: 1/4 of cpu cores). |
 | `region_engine.mito.max_background_purges` | Integer | Auto | Max number of running background purge jobs (default: number of cpu cores). |
+| `region_engine.mito.experimental_compaction_memory_limit` | String | 0 | Memory budget for compaction tasks. Setting it to 0 or "unlimited" disables the limit. |
+| `region_engine.mito.experimental_compaction_on_exhausted` | String | wait | Behavior when compaction cannot acquire memory from the budget.<br/>Options: "wait" (default, 10s), "wait(<duration>)", "fail" |
 | `region_engine.mito.auto_flush_interval` | String | `1h` | Interval to auto flush a region if it has not flushed yet. |
 | `region_engine.mito.global_write_buffer_size` | String | Auto | Global write buffer size for all regions. If not set, it's default to 1/8 of OS memory with a max limitation of 1GB. |
 | `region_engine.mito.global_write_buffer_reject_size` | String | Auto | Global write buffer size threshold to reject write requests. If not set, it's default to 2 times of `global_write_buffer_size` |
@@ -534,6 +543,8 @@
 | `region_engine.mito.write_cache_ttl` | String | Unset | TTL for write cache. |
 | `region_engine.mito.preload_index_cache` | Bool | `true` | Preload index (puffin) files into cache on region open (default: true).<br/>When enabled, index files are loaded into the write cache during region initialization,<br/>which can improve query performance at the cost of longer startup times. |
 | `region_engine.mito.index_cache_percent` | Integer | `20` | Percentage of write cache capacity allocated for index (puffin) files (default: 20).<br/>The remaining capacity is used for data (parquet) files.<br/>Must be between 0 and 100 (exclusive). For example, with a 5GiB write cache and 20% allocation,<br/>1GiB is reserved for index files and 4GiB for data files. |
+| `region_engine.mito.enable_refill_cache_on_read` | Bool | `true` | Enable refilling cache on read operations (default: true).<br/>When disabled, cache refilling on read won't happen. |
+| `region_engine.mito.manifest_cache_size` | String | `256MB` | Capacity for manifest cache (default: 256MB). |
 | `region_engine.mito.sst_write_buffer_size` | String | `8MB` | Buffer size for SST writing. |
 | `region_engine.mito.parallel_scan_channel_size` | Integer | `32` | Capacity of the channel to send data from parallel scan tasks to the main task. |
 | `region_engine.mito.max_concurrent_scan_files` | Integer | `384` | Maximum number of SST files to scan concurrently. |

config/datanode.example.toml

@@ -169,6 +169,14 @@ recovery_parallelism = 2
 ## **It's only used when the provider is `kafka`**.
 broker_endpoints = ["127.0.0.1:9092"]
 
+## The connect timeout for kafka client.
+## **It's only used when the provider is `kafka`**.
+#+ connect_timeout = "3s"
+
+## The timeout for kafka client.
+## **It's only used when the provider is `kafka`**.
+#+ timeout = "3s"
+
 ## The max size of a single producer batch.
 ## Warning: Kafka has a default limit of 1MB per message in a topic.
 ## **It's only used when the provider is `kafka`**.
@@ -225,6 +233,7 @@ overwrite_entry_start_id = false
 # endpoint = "https://s3.amazonaws.com"
 # region = "us-west-2"
 # enable_virtual_host_style = false
+# disable_ec2_metadata = false
 
 # Example of using Oss as the storage.
 # [storage]
@@ -281,18 +290,6 @@ data_home = "./greptimedb_data"
 ## - `Oss`: the data is stored in the Aliyun OSS.
 type = "File"
 
-## Read cache configuration for object storage such as 'S3' etc, it's configured by default when using object storage. It is recommended to configure it when using object storage for better performance.
-## A local file directory, defaults to `{data_home}`. An empty string means disabling.
-## @toml2docs:none-default
-#+ cache_path = ""
-
-## Whether to enable read cache. If not set, the read cache will be enabled by default when using object storage.
-#+ enable_read_cache = true
-
-## The local file cache capacity in bytes. If your disk space is sufficient, it is recommended to set it larger.
-## @toml2docs:none-default
-cache_capacity = "5GiB"
-
 ## The S3 bucket name.
 ## **It's only used when the storage type is `S3`, `Oss` and `Gcs`**.
 ## @toml2docs:none-default
@@ -452,6 +449,15 @@ compress_manifest = false
 ## @toml2docs:none-default="Auto"
 #+ max_background_purges = 8
 
+## Memory budget for compaction tasks. Setting it to 0 or "unlimited" disables the limit.
+## @toml2docs:none-default="0"
+#+ experimental_compaction_memory_limit = "0"
+
+## Behavior when compaction cannot acquire memory from the budget.
+## Options: "wait" (default, 10s), "wait(<duration>)", "fail"
+## @toml2docs:none-default="wait"
+#+ experimental_compaction_on_exhausted = "wait"
+
 ## Interval to auto flush a region if it has not flushed yet.
 auto_flush_interval = "1h"
 
@@ -507,6 +513,13 @@ preload_index_cache = true
 ## 1GiB is reserved for index files and 4GiB for data files.
 index_cache_percent = 20
 
+## Enable refilling cache on read operations (default: true).
+## When disabled, cache refilling on read won't happen.
+enable_refill_cache_on_read = true
+
+## Capacity for manifest cache (default: 256MB).
+manifest_cache_size = "256MB"
+
 ## Buffer size for SST writing.
 sst_write_buffer_size = "8MB"
 

config/frontend.example.toml

@@ -6,9 +6,15 @@ default_timezone = "UTC"
 ## @toml2docs:none-default
 default_column_prefix = "greptime"
 
-## The maximum in-flight write bytes.
+## Maximum total memory for all concurrent write request bodies and messages (HTTP, gRPC, Flight).
+## Set to 0 to disable the limit. Default: "0" (unlimited)
 ## @toml2docs:none-default
-#+ max_in_flight_write_bytes = "500MB"
+#+ max_in_flight_write_bytes = "1GB"
+
+## Policy when write bytes quota is exhausted.
+## Options: "wait" (default, 10s timeout), "wait(<duration>)" (e.g., "wait(30s)"), "fail"
+## @toml2docs:none-default
+#+ write_bytes_exhausted_policy = "wait"
 
 ## The runtime options.
 #+ [runtime]
@@ -35,10 +41,6 @@ timeout = "0s"
 ## The following units are supported: `B`, `KB`, `KiB`, `MB`, `MiB`, `GB`, `GiB`, `TB`, `TiB`, `PB`, `PiB`.
 ## Set to 0 to disable limit.
 body_limit = "64MB"
-## Maximum total memory for all concurrent HTTP request bodies.
-## Set to 0 to disable the limit. Default: "0" (unlimited)
-## @toml2docs:none-default
-#+ max_total_body_memory = "1GB"
 ## HTTP CORS support, it's turned on by default
 ## This allows browser to access http APIs without CORS restrictions
 enable_cors = true
@@ -62,10 +64,6 @@ bind_addr = "127.0.0.1:4001"
 server_addr = "127.0.0.1:4001"
 ## The number of server worker threads.
 runtime_size = 8
-## Maximum total memory for all concurrent gRPC request messages.
-## Set to 0 to disable the limit. Default: "0" (unlimited)
-## @toml2docs:none-default
-#+ max_total_message_memory = "1GB"
 ## Compression mode for frontend side Arrow IPC service. Available options:
 ## - `none`: disable all compression
 ## - `transport`: only enable gRPC transport compression (zstd)
@@ -131,7 +129,6 @@ key_path = ""
 ## For now, gRPC tls config does not support auto reload.
 watch = false
 
-
 ## MySQL server options.
 [mysql]
 ## Whether to enable.

config/metasrv.example.toml

@@ -34,11 +34,18 @@ meta_table_name = "greptime_metakv"
 ## Optional PostgreSQL schema for metadata table and election table name qualification.
 ## When PostgreSQL public schema is not writable (e.g., PostgreSQL 15+ with restricted public),
 ## set this to a writable schema. GreptimeDB will use `meta_schema_name`.`meta_table_name`.
-## GreptimeDB will NOT create the schema automatically; please ensure it exists or the user has permission.
 ## **Only used when backend is `postgres_store`.**
-
 meta_schema_name = "greptime_schema"
 
+## Automatically create PostgreSQL schema if it doesn't exist.
+## When enabled, the system will execute `CREATE SCHEMA IF NOT EXISTS <schema_name>`
+## before creating metadata tables. This is useful in production environments where
+## manual schema creation may be restricted.
+## Default is true.
+## Note: The PostgreSQL user must have CREATE SCHEMA permission for this to work.
+## **Only used when backend is `postgres_store`.**
+auto_create_schema = true
+
 ## Advisory lock id in PostgreSQL for election. Effect when using PostgreSQL as kvbackend
 ## Only used when backend is `postgres_store`.
 meta_election_lock_id = 1
@@ -50,9 +57,6 @@ meta_election_lock_id = 1
 ## For details, please see "https://docs.greptime.com/developer-guide/metasrv/selector".
 selector = "round_robin"
 
-## Store data in memory.
-use_memory_store = false
-
 ## Whether to enable region failover.
 ## This feature is only available on GreptimeDB running on cluster mode and
 ## - Using Remote WAL
@@ -71,6 +75,13 @@ allow_region_failover_on_local_wal = false
 ## Max allowed idle time before removing node info from metasrv memory.
 node_max_idle_time = "24hours"
 
+## Base heartbeat interval for calculating distributed time constants.
+## The frontend heartbeat interval is 6 times of the base heartbeat interval.
+## The flownode/datanode heartbeat interval is 1 times of the base heartbeat interval.
+## e.g., If the base heartbeat interval is 3s, the frontend heartbeat interval is 18s, the flownode/datanode heartbeat interval is 3s.
+## If you change this value, you need to change the heartbeat interval of the flownode/frontend/datanode accordingly.
+#+ heartbeat_interval = "3s"
+
 ## Whether to enable greptimedb telemetry. Enabled by default.
 #+ enable_telemetry = true
 
@@ -109,6 +120,16 @@ key_path = ""
 ## Like "/path/to/ca.crt"
 ca_cert_path = ""
 
+## The backend client options.
+## Currently, only applicable when using etcd as the metadata store.
+#+ [backend_client]
+## The keep alive timeout for backend client.
+#+ keep_alive_timeout = "3s"
+## The keep alive interval for backend client.
+#+ keep_alive_interval = "10s"
+## The connect timeout for backend client.
+#+ connect_timeout = "3s"
+
 ## The gRPC server options.
 [grpc]
 ## The address to bind the gRPC server.
@@ -123,6 +144,10 @@ runtime_size = 8
 max_recv_message_size = "512MB"
 ## The maximum send message size for gRPC server.
 max_send_message_size = "512MB"
+## The server side HTTP/2 keep-alive interval
+#+ http2_keep_alive_interval = "10s"
+## The server side HTTP/2 keep-alive timeout.
+#+ http2_keep_alive_timeout = "3s"
 
 ## The HTTP server options.
 [http]

config/standalone.example.toml

@@ -6,6 +6,16 @@ default_timezone = "UTC"
 ## @toml2docs:none-default
 default_column_prefix = "greptime"
 
+## Maximum total memory for all concurrent write request bodies and messages (HTTP, gRPC, Flight).
+## Set to 0 to disable the limit. Default: "0" (unlimited)
+## @toml2docs:none-default
+#+ max_in_flight_write_bytes = "1GB"
+
+## Policy when write bytes quota is exhausted.
+## Options: "wait" (default, 10s timeout), "wait(<duration>)" (e.g., "wait(30s)"), "fail"
+## @toml2docs:none-default
+#+ write_bytes_exhausted_policy = "wait"
+
 ## Initialize all regions in the background during the startup.
 ## By default, it provides services after all regions have been initialized.
 init_regions_in_background = false
@@ -22,10 +32,6 @@ max_concurrent_queries = 0
 ## Enable telemetry to collect anonymous usage data. Enabled by default.
 #+ enable_telemetry = true
 
-## The maximum in-flight write bytes.
-## @toml2docs:none-default
-#+ max_in_flight_write_bytes = "500MB"
-
 ## The runtime options.
 #+ [runtime]
 ## The number of threads to execute the runtime for global read operations.
@@ -43,10 +49,6 @@ timeout = "0s"
 ## The following units are supported: `B`, `KB`, `KiB`, `MB`, `MiB`, `GB`, `GiB`, `TB`, `TiB`, `PB`, `PiB`.
 ## Set to 0 to disable limit.
 body_limit = "64MB"
-## Maximum total memory for all concurrent HTTP request bodies.
-## Set to 0 to disable the limit. Default: "0" (unlimited)
-## @toml2docs:none-default
-#+ max_total_body_memory = "1GB"
 ## HTTP CORS support, it's turned on by default
 ## This allows browser to access http APIs without CORS restrictions
 enable_cors = true
@@ -67,10 +69,6 @@ prom_validation_mode = "strict"
 bind_addr = "127.0.0.1:4001"
 ## The number of server worker threads.
 runtime_size = 8
-## Maximum total memory for all concurrent gRPC request messages.
-## Set to 0 to disable the limit. Default: "0" (unlimited)
-## @toml2docs:none-default
-#+ max_total_message_memory = "1GB"
 ## The maximum connection age for gRPC connection.
 ## The value can be a human-readable time string. For example: `10m` for ten minutes or `1h` for one hour.
 ## Refer to https://grpc.io/docs/guides/keepalive/ for more details.
@@ -230,6 +228,14 @@ recovery_parallelism = 2
 ## **It's only used when the provider is `kafka`**.
 broker_endpoints = ["127.0.0.1:9092"]
 
+## The connect timeout for kafka client.
+## **It's only used when the provider is `kafka`**.
+#+ connect_timeout = "3s"
+
+## The timeout for kafka client.
+## **It's only used when the provider is `kafka`**.
+#+ timeout = "3s"
+
 ## Automatically create topics for WAL.
 ## Set to `true` to automatically create topics for WAL.
 ## Otherwise, use topics named `topic_name_prefix_[0..num_topics)`
@@ -332,6 +338,7 @@ max_running_procedures = 128
 # endpoint = "https://s3.amazonaws.com"
 # region = "us-west-2"
 # enable_virtual_host_style = false
+# disable_ec2_metadata = false
 
 # Example of using Oss as the storage.
 # [storage]
@@ -388,18 +395,6 @@ data_home = "./greptimedb_data"
 ## - `Oss`: the data is stored in the Aliyun OSS.
 type = "File"
 
-## Whether to enable read cache. If not set, the read cache will be enabled by default when using object storage.
-#+ enable_read_cache = true
-
-## Read cache configuration for object storage such as 'S3' etc, it's configured by default when using object storage. It is recommended to configure it when using object storage for better performance.
-## A local file directory, defaults to `{data_home}`. An empty string means disabling.
-## @toml2docs:none-default
-#+ cache_path = ""
-
-## The local file cache capacity in bytes. If your disk space is sufficient, it is recommended to set it larger.
-## @toml2docs:none-default
-cache_capacity = "5GiB"
-
 ## The S3 bucket name.
 ## **It's only used when the storage type is `S3`, `Oss` and `Gcs`**.
 ## @toml2docs:none-default
@@ -546,6 +541,15 @@ compress_manifest = false
 ## @toml2docs:none-default="Auto"
 #+ max_background_purges = 8
 
+## Memory budget for compaction tasks. Setting it to 0 or "unlimited" disables the limit.
+## @toml2docs:none-default="0"
+#+ experimental_compaction_memory_limit = "0"
+
+## Behavior when compaction cannot acquire memory from the budget.
+## Options: "wait" (default, 10s), "wait(<duration>)", "fail"
+## @toml2docs:none-default="wait"
+#+ experimental_compaction_on_exhausted = "wait"
+
 ## Interval to auto flush a region if it has not flushed yet.
 auto_flush_interval = "1h"
 
@@ -601,6 +605,13 @@ preload_index_cache = true
 ## 1GiB is reserved for index files and 4GiB for data files.
 index_cache_percent = 20
 
+## Enable refilling cache on read operations (default: true).
+## When disabled, cache refilling on read won't happen.
+enable_refill_cache_on_read = true
+
+## Capacity for manifest cache (default: 256MB).
+manifest_cache_size = "256MB"
+
 ## Buffer size for SST writing.
 sst_write_buffer_size = "8MB"
 

flake.lock

@@ -8,11 +8,11 @@
         "rust-analyzer-src": "rust-analyzer-src"
       },
       "locked": {
-        "lastModified": 1760078406,
-        "narHash": "sha256-JeJK0ZA845PtkCHkfo4KjeI1mYrsr2s3cxBYKhF4BoE=",
+        "lastModified": 1765252472,
+        "narHash": "sha256-byMt/uMi7DJ8tRniFopDFZMO3leSjGp6GS4zWOFT+uQ=",
         "owner": "nix-community",
         "repo": "fenix",
-        "rev": "351277c60d104944122ee389cdf581c5ce2c6732",
+        "rev": "8456b985f6652e3eef0632ee9992b439735c5544",
         "type": "github"
       },
       "original": {
@@ -41,16 +41,16 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1759994382,
-        "narHash": "sha256-wSK+3UkalDZRVHGCRikZ//CyZUJWDJkBDTQX1+G77Ow=",
+        "lastModified": 1764983851,
+        "narHash": "sha256-y7RPKl/jJ/KAP/VKLMghMgXTlvNIJMHKskl8/Uuar7o=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "5da4a26309e796daa7ffca72df93dbe53b8164c7",
+        "rev": "d9bc5c7dceb30d8d6fafa10aeb6aa8a48c218454",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-25.05",
+        "ref": "nixos-25.11",
         "repo": "nixpkgs",
         "type": "github"
       }
@@ -65,11 +65,11 @@
     "rust-analyzer-src": {
       "flake": false,
       "locked": {
-        "lastModified": 1760014945,
-        "narHash": "sha256-ySdl7F9+oeWNHVrg3QL/brazqmJvYFEdpGnF3pyoDH8=",
+        "lastModified": 1765120009,
+        "narHash": "sha256-nG76b87rkaDzibWbnB5bYDm6a52b78A+fpm+03pqYIw=",
         "owner": "rust-lang",
         "repo": "rust-analyzer",
-        "rev": "90d2e1ce4dfe7dc49250a8b88a0f08ffdb9cb23f",
+        "rev": "5e3e9c4e61bba8a5e72134b9ffefbef8f531d008",
         "type": "github"
       },
       "original": {

flake.nix

@@ -2,7 +2,7 @@
   description = "Development environment flake";
 
   inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.11";
     fenix = {
       url = "github:nix-community/fenix";
       inputs.nixpkgs.follows = "nixpkgs";
@@ -48,7 +48,7 @@
             gnuplot ## for cargo bench
           ];
 
-          LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath buildInputs;
+          buildInputs = buildInputs;
           NIX_HARDENING_ENABLE = "";
         };
       });

src/api/src/helper.rs

@@ -708,6 +708,7 @@ fn ddl_request_type(request: &DdlRequest) -> &'static str {
         Some(Expr::CreateView(_)) => "ddl.create_view",
         Some(Expr::DropView(_)) => "ddl.drop_view",
         Some(Expr::AlterDatabase(_)) => "ddl.alter_database",
+        Some(Expr::CommentOn(_)) => "ddl.comment_on",
         None => "ddl.empty",
     }
 }

src/auth/Cargo.toml

@@ -15,11 +15,11 @@ workspace = true
 api.workspace = true
 async-trait.workspace = true
 common-base.workspace = true
+common-config.workspace = true
 common-error.workspace = true
 common-macro.workspace = true
 common-telemetry.workspace = true
 digest = "0.10"
-notify.workspace = true
 sha1 = "0.10"
 snafu.workspace = true
 sql.workspace = true

src/auth/src/error.rs

@@ -75,11 +75,12 @@ pub enum Error {
         username: String,
     },
 
-    #[snafu(display("Failed to initialize a watcher for file {}", path))]
+    #[snafu(display("Failed to initialize a file watcher"))]
     FileWatch {
-        path: String,
         #[snafu(source)]
-        error: notify::Error,
+        source: common_config::error::Error,
+        #[snafu(implicit)]
+        location: Location,
     },
 
     #[snafu(display("User is not authorized to perform this action"))]

src/auth/src/user_provider/watch_file_user_provider.rs

@@ -12,16 +12,14 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use std::path::Path;
-use std::sync::mpsc::channel;
 use std::sync::{Arc, Mutex};
 
 use async_trait::async_trait;
+use common_config::file_watcher::{FileWatcherBuilder, FileWatcherConfig};
 use common_telemetry::{info, warn};
-use notify::{EventKind, RecursiveMode, Watcher};
-use snafu::{ResultExt, ensure};
+use snafu::ResultExt;
 
-use crate::error::{FileWatchSnafu, InvalidConfigSnafu, Result};
+use crate::error::{FileWatchSnafu, Result};
 use crate::user_provider::{UserInfoMap, authenticate_with_credential, load_credential_from_file};
 use crate::{Identity, Password, UserInfoRef, UserProvider};
 
@@ -41,61 +39,36 @@ impl WatchFileUserProvider {
     pub fn new(filepath: &str) -> Result<Self> {
         let credential = load_credential_from_file(filepath)?;
         let users = Arc::new(Mutex::new(credential));
-        let this = WatchFileUserProvider {
-            users: users.clone(),
-        };
 
-        let (tx, rx) = channel::<notify::Result<notify::Event>>();
-        let mut debouncer =
-            notify::recommended_watcher(tx).context(FileWatchSnafu { path: "<none>" })?;
-        let mut dir = Path::new(filepath).to_path_buf();
-        ensure!(
-            dir.pop(),
-            InvalidConfigSnafu {
-                value: filepath,
-                msg: "UserProvider path must be a file path",
-            }
-        );
-        debouncer
-            .watch(&dir, RecursiveMode::NonRecursive)
-            .context(FileWatchSnafu { path: filepath })?;
+        let users_clone = users.clone();
+        let filepath_owned = filepath.to_string();
 
-        let filepath = filepath.to_string();
-        std::thread::spawn(move || {
-            let filename = Path::new(&filepath).file_name();
-            let _hold = debouncer;
-            while let Ok(res) = rx.recv() {
-                if let Ok(event) = res {
-                    let is_this_file = event.paths.iter().any(|p| p.file_name() == filename);
-                    let is_relevant_event = matches!(
-                        event.kind,
-                        EventKind::Modify(_) | EventKind::Create(_) | EventKind::Remove(_)
-                    );
-                    if is_this_file && is_relevant_event {
-                        info!(?event.kind, "User provider file {} changed", &filepath);
-                        match load_credential_from_file(&filepath) {
+        FileWatcherBuilder::new()
+            .watch_path(filepath)
+            .context(FileWatchSnafu)?
+            .config(FileWatcherConfig::new())
+            .spawn(move || match load_credential_from_file(&filepath_owned) {
                 Ok(credential) => {
-                                let mut users =
-                                    users.lock().expect("users credential must be valid");
+                    let mut users = users_clone.lock().expect("users credential must be valid");
                     #[cfg(not(test))]
-                                info!("User provider file {filepath} reloaded");
+                    info!("User provider file {} reloaded", &filepath_owned);
                     #[cfg(test)]
-                                info!("User provider file {filepath} reloaded: {credential:?}");
+                    info!(
+                        "User provider file {} reloaded: {:?}",
+                        &filepath_owned, credential
+                    );
                     *users = credential;
                 }
                 Err(err) => {
                     warn!(
                         ?err,
-                                    "Fail to load credential from file {filepath}; keep the old one",
+                        "Fail to load credential from file {}; keep the old one", &filepath_owned
                     )
                 }
-                        }
-                    }
-                }
-            }
-        });
+            })
+            .context(FileWatchSnafu)?;
 
-        Ok(this)
+        Ok(WatchFileUserProvider { users })
     }
 }
 

src/catalog/src/system_schema/information_schema.rs

@@ -428,7 +428,7 @@ pub trait InformationExtension {
 }
 
 /// The request to inspect the datanode.
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive(Debug, Clone, PartialEq)]
 pub struct DatanodeInspectRequest {
     /// Kind to fetch from datanode.
     pub kind: DatanodeInspectKind,

src/cli/Cargo.toml

@@ -67,6 +67,7 @@ tracing-appender.workspace = true
 
 [dev-dependencies]
 common-meta = { workspace = true, features = ["testing"] }
+common-test-util.workspace = true
 common-version.workspace = true
 serde.workspace = true
 tempfile.workspace = true

src/cli/src/common.rs

@@ -15,5 +15,8 @@
 mod object_store;
 mod store;
 
-pub use object_store::{ObjectStoreConfig, new_fs_object_store};
+pub use object_store::{
+    ObjectStoreConfig, PrefixedAzblobConnection, PrefixedGcsConnection, PrefixedOssConnection,
+    PrefixedS3Connection, new_fs_object_store,
+};
 pub use store::StoreConfig;

src/cli/src/common/object_store.rs

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use common_base::secrets::SecretString;
+use common_base::secrets::{ExposeSecret, SecretString};
 use common_error::ext::BoxedError;
 use object_store::services::{Azblob, Fs, Gcs, Oss, S3};
 use object_store::util::{with_instrument_layers, with_retry_layers};
@@ -22,9 +22,69 @@ use snafu::ResultExt;
 
 use crate::error::{self};
 
+/// Trait to convert CLI field types to target struct field types.
+/// This enables `Option<SecretString>` (CLI) -> `SecretString` (target) conversions,
+/// allowing us to distinguish "not provided" from "provided but empty".
+trait IntoField<T> {
+    fn into_field(self) -> T;
+}
+
+/// Identity conversion for types that are the same.
+impl<T> IntoField<T> for T {
+    fn into_field(self) -> T {
+        self
+    }
+}
+
+/// Convert `Option<SecretString>` to `SecretString`, using default for None.
+impl IntoField<SecretString> for Option<SecretString> {
+    fn into_field(self) -> SecretString {
+        self.unwrap_or_default()
+    }
+}
+
+/// Trait for checking if a field is effectively empty.
+///
+/// **`is_empty()`**: Checks if the field has no meaningful value
+/// - Used when backend is enabled to validate required fields
+/// - `None`, `Some("")`, `false`, or `""` are considered empty
+trait FieldValidator {
+    /// Check if the field is empty (has no meaningful value).
+    fn is_empty(&self) -> bool;
+}
+
+/// String fields: empty if the string is empty
+impl FieldValidator for String {
+    fn is_empty(&self) -> bool {
+        self.is_empty()
+    }
+}
+
+/// Bool fields: false is considered "empty", true is "provided"
+impl FieldValidator for bool {
+    fn is_empty(&self) -> bool {
+        !self
+    }
+}
+
+/// Option<String> fields: None or empty content is empty
+impl FieldValidator for Option<String> {
+    fn is_empty(&self) -> bool {
+        self.as_ref().is_none_or(|s| s.is_empty())
+    }
+}
+
+/// Option<SecretString> fields: None or empty secret is empty
+/// For secrets, Some("") is treated as "not provided" for both checks
+impl FieldValidator for Option<SecretString> {
+    fn is_empty(&self) -> bool {
+        self.as_ref().is_none_or(|s| s.expose_secret().is_empty())
+    }
+}
+
 macro_rules! wrap_with_clap_prefix {
     (
-        $new_name:ident, $prefix:literal, $base:ty, {
+        $new_name:ident, $prefix:literal, $enable_flag:literal, $base:ty, {
             $( $( #[doc = $doc:expr] )? $( #[alias = $alias:literal] )? $field:ident : $type:ty $( = $default:expr )? ),* $(,)?
         }
     ) => {
@@ -34,15 +94,16 @@ macro_rules! wrap_with_clap_prefix {
                 $(
                     $( #[doc = $doc] )?
                     $( #[clap(alias = $alias)] )?
-                    #[clap(long $(, default_value_t = $default )? )]
-                    [<$prefix $field>]: $type,
+                    #[clap(long, requires = $enable_flag $(, default_value_t = $default )? )]
+                    pub [<$prefix $field>]: $type,
                 )*
             }
 
             impl From<$new_name> for $base {
                 fn from(w: $new_name) -> Self {
                     Self {
-                        $( $field: w.[<$prefix $field>] ),*
+                        // Use into_field() to handle Option<SecretString> -> SecretString conversion
+                        $( $field: w.[<$prefix $field>].into_field() ),*
                     }
                 }
             }
@@ -50,9 +111,90 @@ macro_rules! wrap_with_clap_prefix {
     };
 }
 
+/// Macro for declarative backend validation.
+///
+/// # Validation Rules
+///
+/// For each storage backend (S3, OSS, GCS, Azblob), this function validates:
+/// **When backend is enabled** (e.g., `--s3`): All required fields must be non-empty
+///
+/// Note: When backend is disabled, clap's `requires` attribute ensures no configuration
+/// fields can be provided at parse time.
+///
+/// # Syntax
+///
+/// ```ignore
+/// validate_backend!(
+///     enable: self.enable_s3,
+///     name: "S3",
+///     required: [(field1, "name1"), (field2, "name2"), ...],
+///     custom_validator: |missing| { ... }  // optional
+/// )
+/// ```
+///
+/// # Arguments
+///
+/// - `enable`: Boolean expression indicating if backend is enabled
+/// - `name`: Human-readable backend name for error messages
+/// - `required`: Array of (field_ref, field_name) tuples for required fields
+/// - `custom_validator`: Optional closure for complex validation logic
+///
+/// # Example
+///
+/// ```ignore
+/// validate_backend!(
+///     enable: self.enable_s3,
+///     name: "S3",
+///     required: [
+///         (&self.s3.s3_bucket, "bucket"),
+///         (&self.s3.s3_access_key_id, "access key ID"),
+///     ]
+/// )
+/// ```
+macro_rules! validate_backend {
+    (
+        enable: $enable:expr,
+        name: $backend_name:expr,
+        required: [ $( ($field:expr, $field_name:expr) ),* $(,)? ]
+        $(, custom_validator: $custom_validator:expr)?
+    ) => {{
+        if $enable {
+            // Check required fields when backend is enabled
+            let mut missing = Vec::new();
+            $(
+                if FieldValidator::is_empty($field) {
+                    missing.push($field_name);
+                }
+            )*
+
+            // Run custom validation if provided
+            $(
+                $custom_validator(&mut missing);
+            )?
+
+            if !missing.is_empty() {
+                return Err(BoxedError::new(
+                    error::MissingConfigSnafu {
+                        msg: format!(
+                            "{} {} must be set when --{} is enabled.",
+                            $backend_name,
+                            missing.join(", "),
+                            $backend_name.to_lowercase()
+                        ),
+                    }
+                    .build(),
+                ));
+            }
+        }
+
+        Ok(())
+    }};
+}
+
 wrap_with_clap_prefix! {
     PrefixedAzblobConnection,
     "azblob-",
+    "enable_azblob",
     AzblobConnection,
     {
         #[doc = "The container of the object store."]
@@ -60,9 +202,9 @@ wrap_with_clap_prefix! {
         #[doc = "The root of the object store."]
         root: String = Default::default(),
         #[doc = "The account name of the object store."]
-        account_name: SecretString = Default::default(),
+        account_name: Option<SecretString>,
         #[doc = "The account key of the object store."]
-        account_key: SecretString = Default::default(),
+        account_key: Option<SecretString>,
         #[doc = "The endpoint of the object store."]
         endpoint: String = Default::default(),
         #[doc = "The SAS token of the object store."]
@@ -70,9 +212,33 @@ wrap_with_clap_prefix! {
     }
 }
 
+impl PrefixedAzblobConnection {
+    pub fn validate(&self) -> Result<(), BoxedError> {
+        validate_backend!(
+            enable: true,
+            name: "AzBlob",
+            required: [
+                (&self.azblob_container, "container"),
+                (&self.azblob_root, "root"),
+                (&self.azblob_account_name, "account name"),
+                (&self.azblob_endpoint, "endpoint"),
+            ],
+            custom_validator: |missing: &mut Vec<&str>| {
+                // account_key is only required if sas_token is not provided
+                if self.azblob_sas_token.is_none()
+                    && self.azblob_account_key.is_empty()
+                {
+                    missing.push("account key (when sas_token is not provided)");
+                }
+            }
+        )
+    }
+}
+
 wrap_with_clap_prefix! {
     PrefixedS3Connection,
     "s3-",
+    "enable_s3",
     S3Connection,
     {
         #[doc = "The bucket of the object store."]
@@ -80,21 +246,39 @@ wrap_with_clap_prefix! {
         #[doc = "The root of the object store."]
         root: String = Default::default(),
         #[doc = "The access key ID of the object store."]
-        access_key_id: SecretString = Default::default(),
+        access_key_id: Option<SecretString>,
         #[doc = "The secret access key of the object store."]
-        secret_access_key: SecretString = Default::default(),
+        secret_access_key: Option<SecretString>,
         #[doc = "The endpoint of the object store."]
         endpoint: Option<String>,
         #[doc = "The region of the object store."]
         region: Option<String>,
         #[doc = "Enable virtual host style for the object store."]
         enable_virtual_host_style: bool = Default::default(),
+        #[doc = "Disable EC2 metadata service for the object store."]
+        disable_ec2_metadata: bool = Default::default(),
+    }
+}
+
+impl PrefixedS3Connection {
+    pub fn validate(&self) -> Result<(), BoxedError> {
+        validate_backend!(
+            enable: true,
+            name: "S3",
+            required: [
+                (&self.s3_bucket, "bucket"),
+                (&self.s3_access_key_id, "access key ID"),
+                (&self.s3_secret_access_key, "secret access key"),
+                (&self.s3_region, "region"),
+            ]
+        )
     }
 }
 
 wrap_with_clap_prefix! {
     PrefixedOssConnection,
     "oss-",
+    "enable_oss",
     OssConnection,
     {
         #[doc = "The bucket of the object store."]
@@ -102,17 +286,33 @@ wrap_with_clap_prefix! {
         #[doc = "The root of the object store."]
         root: String = Default::default(),
         #[doc = "The access key ID of the object store."]
-        access_key_id: SecretString = Default::default(),
+        access_key_id: Option<SecretString>,
         #[doc = "The access key secret of the object store."]
-        access_key_secret: SecretString = Default::default(),
+        access_key_secret: Option<SecretString>,
         #[doc = "The endpoint of the object store."]
         endpoint: String = Default::default(),
     }
 }
 
+impl PrefixedOssConnection {
+    pub fn validate(&self) -> Result<(), BoxedError> {
+        validate_backend!(
+            enable: true,
+            name: "OSS",
+            required: [
+                (&self.oss_bucket, "bucket"),
+                (&self.oss_access_key_id, "access key ID"),
+                (&self.oss_access_key_secret, "access key secret"),
+                (&self.oss_endpoint, "endpoint"),
+            ]
+        )
+    }
+}
+
 wrap_with_clap_prefix! {
     PrefixedGcsConnection,
     "gcs-",
+    "enable_gcs",
     GcsConnection,
     {
         #[doc = "The root of the object store."]
@@ -122,40 +322,72 @@ wrap_with_clap_prefix! {
         #[doc = "The scope of the object store."]
         scope: String = Default::default(),
         #[doc = "The credential path of the object store."]
-        credential_path: SecretString = Default::default(),
+        credential_path: Option<SecretString>,
         #[doc = "The credential of the object store."]
-        credential: SecretString = Default::default(),
+        credential: Option<SecretString>,
         #[doc = "The endpoint of the object store."]
         endpoint: String = Default::default(),
     }
 }
 
-/// common config for object store.
+impl PrefixedGcsConnection {
+    pub fn validate(&self) -> Result<(), BoxedError> {
+        validate_backend!(
+            enable: true,
+            name: "GCS",
+            required: [
+                (&self.gcs_bucket, "bucket"),
+                (&self.gcs_root, "root"),
+                (&self.gcs_scope, "scope"),
+            ]
+            // No custom_validator needed: GCS supports Application Default Credentials (ADC)
+            // where neither credential_path nor credential is required.
+            // Endpoint is also optional (defaults to https://storage.googleapis.com).
+        )
+    }
+}
+
+/// Common config for object store.
+///
+/// # Dependency Enforcement
+///
+/// Each backend's configuration fields (e.g., `--s3-bucket`) requires its corresponding
+/// enable flag (e.g., `--s3`) to be present. This is enforced by `clap` at parse time
+/// using the `requires` attribute.
+///
+/// For example, attempting to use `--s3-bucket my-bucket` without `--s3` will result in:
+/// ```text
+/// error: The argument '--s3-bucket <BUCKET>' requires '--s3'
+/// ```
+///
+/// This ensures that users cannot accidentally provide backend-specific configuration
+/// without explicitly enabling that backend.
 #[derive(clap::Parser, Debug, Clone, PartialEq, Default)]
+#[clap(group(clap::ArgGroup::new("storage_backend").required(false).multiple(false)))]
 pub struct ObjectStoreConfig {
     /// Whether to use S3 object store.
-    #[clap(long, alias = "s3")]
+    #[clap(long = "s3", group = "storage_backend")]
     pub enable_s3: bool,
 
     #[clap(flatten)]
     pub s3: PrefixedS3Connection,
 
     /// Whether to use OSS.
-    #[clap(long, alias = "oss")]
+    #[clap(long = "oss", group = "storage_backend")]
     pub enable_oss: bool,
 
     #[clap(flatten)]
     pub oss: PrefixedOssConnection,
 
     /// Whether to use GCS.
-    #[clap(long, alias = "gcs")]
+    #[clap(long = "gcs", group = "storage_backend")]
     pub enable_gcs: bool,
 
     #[clap(flatten)]
     pub gcs: PrefixedGcsConnection,
 
     /// Whether to use Azure Blob.
-    #[clap(long, alias = "azblob")]
+    #[clap(long = "azblob", group = "storage_backend")]
     pub enable_azblob: bool,
 
     #[clap(flatten)]
@@ -173,52 +405,66 @@ pub fn new_fs_object_store(root: &str) -> std::result::Result<ObjectStore, Boxed
     Ok(with_instrument_layers(object_store, false))
 }
 
+macro_rules! gen_object_store_builder {
+    ($method:ident, $field:ident, $conn_type:ty, $service_type:ty) => {
+        pub fn $method(&self) -> Result<ObjectStore, BoxedError> {
+            let config = <$conn_type>::from(self.$field.clone());
+            common_telemetry::info!(
+                "Building object store with {}: {:?}",
+                stringify!($field),
+                config
+            );
+            let object_store = ObjectStore::new(<$service_type>::from(&config))
+                .context(error::InitBackendSnafu)
+                .map_err(BoxedError::new)?
+                .finish();
+            Ok(with_instrument_layers(
+                with_retry_layers(object_store),
+                false,
+            ))
+        }
+    };
+}
+
 impl ObjectStoreConfig {
+    gen_object_store_builder!(build_s3, s3, S3Connection, S3);
+
+    gen_object_store_builder!(build_oss, oss, OssConnection, Oss);
+
+    gen_object_store_builder!(build_gcs, gcs, GcsConnection, Gcs);
+
+    gen_object_store_builder!(build_azblob, azblob, AzblobConnection, Azblob);
+
+    pub fn validate(&self) -> Result<(), BoxedError> {
+        if self.enable_s3 {
+            self.s3.validate()?;
+        }
+        if self.enable_oss {
+            self.oss.validate()?;
+        }
+        if self.enable_gcs {
+            self.gcs.validate()?;
+        }
+        if self.enable_azblob {
+            self.azblob.validate()?;
+        }
+        Ok(())
+    }
+
     /// Builds the object store from the config.
     pub fn build(&self) -> Result<Option<ObjectStore>, BoxedError> {
-        let object_store = if self.enable_s3 {
-            let s3 = S3Connection::from(self.s3.clone());
-            common_telemetry::info!("Building object store with s3: {:?}", s3);
-            Some(
-                ObjectStore::new(S3::from(&s3))
-                    .context(error::InitBackendSnafu)
-                    .map_err(BoxedError::new)?
-                    .finish(),
-            )
+        self.validate()?;
+
+        if self.enable_s3 {
+            self.build_s3().map(Some)
         } else if self.enable_oss {
-            let oss = OssConnection::from(self.oss.clone());
-            common_telemetry::info!("Building object store with oss: {:?}", oss);
-            Some(
-                ObjectStore::new(Oss::from(&oss))
-                    .context(error::InitBackendSnafu)
-                    .map_err(BoxedError::new)?
-                    .finish(),
-            )
+            self.build_oss().map(Some)
         } else if self.enable_gcs {
-            let gcs = GcsConnection::from(self.gcs.clone());
-            common_telemetry::info!("Building object store with gcs: {:?}", gcs);
-            Some(
-                ObjectStore::new(Gcs::from(&gcs))
-                    .context(error::InitBackendSnafu)
-                    .map_err(BoxedError::new)?
-                    .finish(),
-            )
+            self.build_gcs().map(Some)
         } else if self.enable_azblob {
-            let azblob = AzblobConnection::from(self.azblob.clone());
-            common_telemetry::info!("Building object store with azblob: {:?}", azblob);
-            Some(
-                ObjectStore::new(Azblob::from(&azblob))
-                    .context(error::InitBackendSnafu)
-                    .map_err(BoxedError::new)?
-                    .finish(),
-            )
+            self.build_azblob().map(Some)
         } else {
-            None
-        };
-
-        let object_store = object_store
-            .map(|object_store| with_instrument_layers(with_retry_layers(object_store), false));
-
-        Ok(object_store)
+            Ok(None)
+        }
     }
 }

src/cli/src/common/store.rs

@@ -19,7 +19,7 @@ use common_error::ext::BoxedError;
 use common_meta::kv_backend::KvBackendRef;
 use common_meta::kv_backend::chroot::ChrootKvBackend;
 use common_meta::kv_backend::etcd::EtcdStore;
-use meta_srv::metasrv::BackendImpl;
+use meta_srv::metasrv::{BackendClientOptions, BackendImpl};
 use meta_srv::utils::etcd::create_etcd_client_with_tls;
 use servers::tls::{TlsMode, TlsOption};
 
@@ -61,6 +61,12 @@ pub struct StoreConfig {
     #[cfg(feature = "pg_kvbackend")]
     #[clap(long)]
     pub meta_schema_name: Option<String>,
+
+    /// Automatically create PostgreSQL schema if it doesn't exist (default: true).
+    #[cfg(feature = "pg_kvbackend")]
+    #[clap(long, default_value_t = true)]
+    pub auto_create_schema: bool,
+
     /// TLS mode for backend store connections (etcd, PostgreSQL, MySQL)
     #[clap(long = "backend-tls-mode", value_enum, default_value = "disable")]
     pub backend_tls_mode: TlsMode,
@@ -112,7 +118,11 @@ impl StoreConfig {
             let kvbackend = match self.backend {
                 BackendImpl::EtcdStore => {
                     let tls_config = self.tls_config();
-                    let etcd_client = create_etcd_client_with_tls(store_addrs, tls_config.as_ref())
+                    let etcd_client = create_etcd_client_with_tls(
+                        store_addrs,
+                        &BackendClientOptions::default(),
+                        tls_config.as_ref(),
+                    )
                     .await
                     .map_err(BoxedError::new)?;
                     Ok(EtcdStore::with_etcd_client(etcd_client, max_txn_ops))
@@ -134,6 +144,7 @@ impl StoreConfig {
                         schema_name,
                         table_name,
                         max_txn_ops,
+                        self.auto_create_schema,
                     )
                     .await
                     .map_err(BoxedError::new)?)

src/cli/src/data.rs

@@ -14,6 +14,7 @@
 
 mod export;
 mod import;
+mod storage_export;
 
 use clap::Subcommand;
 use client::DEFAULT_CATALOG_NAME;

src/cli/src/data/storage_export.rs

@@ -0,0 +1,373 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::path::PathBuf;
+
+use common_base::secrets::{ExposeSecret, SecretString};
+use common_error::ext::BoxedError;
+
+use crate::common::{
+    PrefixedAzblobConnection, PrefixedGcsConnection, PrefixedOssConnection, PrefixedS3Connection,
+};
+
+/// Helper function to extract secret string from Option<SecretString>.
+/// Returns empty string if None.
+fn expose_optional_secret(secret: &Option<SecretString>) -> &str {
+    secret
+        .as_ref()
+        .map(|s| s.expose_secret().as_str())
+        .unwrap_or("")
+}
+
+/// Helper function to format root path with leading slash if non-empty.
+fn format_root_path(root: &str) -> String {
+    if root.is_empty() {
+        String::new()
+    } else {
+        format!("/{}", root)
+    }
+}
+
+/// Helper function to mask multiple secrets in a string.
+fn mask_secrets(mut sql: String, secrets: &[&str]) -> String {
+    for secret in secrets {
+        if !secret.is_empty() {
+            sql = sql.replace(secret, "[REDACTED]");
+        }
+    }
+    sql
+}
+
+/// Helper function to format storage URI.
+fn format_uri(scheme: &str, bucket: &str, root: &str, path: &str) -> String {
+    let root = format_root_path(root);
+    format!("{}://{}{}/{}", scheme, bucket, root, path)
+}
+
+/// Trait for storage backends that can be used for data export.
+pub trait StorageExport: Send + Sync {
+    /// Generate the storage path for COPY DATABASE command.
+    /// Returns (path, connection_string) where connection_string includes CONNECTION clause.
+    fn get_storage_path(&self, catalog: &str, schema: &str) -> (String, String);
+
+    /// Format the output path for logging purposes.
+    fn format_output_path(&self, file_path: &str) -> String;
+
+    /// Mask sensitive information in SQL commands for safe logging.
+    fn mask_sensitive_info(&self, sql: &str) -> String;
+}
+
+macro_rules! define_backend {
+    ($name:ident, $config:ty) => {
+        #[derive(Clone)]
+        pub struct $name {
+            config: $config,
+        }
+
+        impl $name {
+            pub fn new(config: $config) -> Result<Self, BoxedError> {
+                config.validate()?;
+                Ok(Self { config })
+            }
+        }
+    };
+}
+
+/// Local file system storage backend.
+#[derive(Clone)]
+pub struct FsBackend {
+    output_dir: String,
+}
+
+impl FsBackend {
+    pub fn new(output_dir: String) -> Self {
+        Self { output_dir }
+    }
+}
+
+impl StorageExport for FsBackend {
+    fn get_storage_path(&self, catalog: &str, schema: &str) -> (String, String) {
+        if self.output_dir.is_empty() {
+            unreachable!("output_dir must be set when not using remote storage")
+        }
+        let path = PathBuf::from(&self.output_dir)
+            .join(catalog)
+            .join(format!("{schema}/"))
+            .to_string_lossy()
+            .to_string();
+        (path, String::new())
+    }
+
+    fn format_output_path(&self, file_path: &str) -> String {
+        format!("{}/{}", self.output_dir, file_path)
+    }
+
+    fn mask_sensitive_info(&self, sql: &str) -> String {
+        sql.to_string()
+    }
+}
+
+define_backend!(S3Backend, PrefixedS3Connection);
+
+impl StorageExport for S3Backend {
+    fn get_storage_path(&self, catalog: &str, schema: &str) -> (String, String) {
+        let s3_path = format_uri(
+            "s3",
+            &self.config.s3_bucket,
+            &self.config.s3_root,
+            &format!("{}/{}/", catalog, schema),
+        );
+
+        let mut connection_options = vec![
+            format!(
+                "ACCESS_KEY_ID='{}'",
+                expose_optional_secret(&self.config.s3_access_key_id)
+            ),
+            format!(
+                "SECRET_ACCESS_KEY='{}'",
+                expose_optional_secret(&self.config.s3_secret_access_key)
+            ),
+        ];
+
+        if let Some(region) = &self.config.s3_region {
+            connection_options.push(format!("REGION='{}'", region));
+        }
+
+        if let Some(endpoint) = &self.config.s3_endpoint {
+            connection_options.push(format!("ENDPOINT='{}'", endpoint));
+        }
+
+        let connection_str = format!(" CONNECTION ({})", connection_options.join(", "));
+        (s3_path, connection_str)
+    }
+
+    fn format_output_path(&self, file_path: &str) -> String {
+        format_uri(
+            "s3",
+            &self.config.s3_bucket,
+            &self.config.s3_root,
+            file_path,
+        )
+    }
+
+    fn mask_sensitive_info(&self, sql: &str) -> String {
+        mask_secrets(
+            sql.to_string(),
+            &[
+                expose_optional_secret(&self.config.s3_access_key_id),
+                expose_optional_secret(&self.config.s3_secret_access_key),
+            ],
+        )
+    }
+}
+
+define_backend!(OssBackend, PrefixedOssConnection);
+
+impl StorageExport for OssBackend {
+    fn get_storage_path(&self, catalog: &str, schema: &str) -> (String, String) {
+        let oss_path = format_uri(
+            "oss",
+            &self.config.oss_bucket,
+            &self.config.oss_root,
+            &format!("{}/{}/", catalog, schema),
+        );
+
+        let connection_options = [
+            format!(
+                "ACCESS_KEY_ID='{}'",
+                expose_optional_secret(&self.config.oss_access_key_id)
+            ),
+            format!(
+                "ACCESS_KEY_SECRET='{}'",
+                expose_optional_secret(&self.config.oss_access_key_secret)
+            ),
+        ];
+
+        let connection_str = format!(" CONNECTION ({})", connection_options.join(", "));
+        (oss_path, connection_str)
+    }
+
+    fn format_output_path(&self, file_path: &str) -> String {
+        format_uri(
+            "oss",
+            &self.config.oss_bucket,
+            &self.config.oss_root,
+            file_path,
+        )
+    }
+
+    fn mask_sensitive_info(&self, sql: &str) -> String {
+        mask_secrets(
+            sql.to_string(),
+            &[
+                expose_optional_secret(&self.config.oss_access_key_id),
+                expose_optional_secret(&self.config.oss_access_key_secret),
+            ],
+        )
+    }
+}
+
+define_backend!(GcsBackend, PrefixedGcsConnection);
+
+impl StorageExport for GcsBackend {
+    fn get_storage_path(&self, catalog: &str, schema: &str) -> (String, String) {
+        let gcs_path = format_uri(
+            "gcs",
+            &self.config.gcs_bucket,
+            &self.config.gcs_root,
+            &format!("{}/{}/", catalog, schema),
+        );
+
+        let mut connection_options = Vec::new();
+
+        let credential_path = expose_optional_secret(&self.config.gcs_credential_path);
+        if !credential_path.is_empty() {
+            connection_options.push(format!("CREDENTIAL_PATH='{}'", credential_path));
+        }
+
+        let credential = expose_optional_secret(&self.config.gcs_credential);
+        if !credential.is_empty() {
+            connection_options.push(format!("CREDENTIAL='{}'", credential));
+        }
+
+        if !self.config.gcs_endpoint.is_empty() {
+            connection_options.push(format!("ENDPOINT='{}'", self.config.gcs_endpoint));
+        }
+
+        let connection_str = if connection_options.is_empty() {
+            String::new()
+        } else {
+            format!(" CONNECTION ({})", connection_options.join(", "))
+        };
+
+        (gcs_path, connection_str)
+    }
+
+    fn format_output_path(&self, file_path: &str) -> String {
+        format_uri(
+            "gcs",
+            &self.config.gcs_bucket,
+            &self.config.gcs_root,
+            file_path,
+        )
+    }
+
+    fn mask_sensitive_info(&self, sql: &str) -> String {
+        mask_secrets(
+            sql.to_string(),
+            &[
+                expose_optional_secret(&self.config.gcs_credential_path),
+                expose_optional_secret(&self.config.gcs_credential),
+            ],
+        )
+    }
+}
+
+define_backend!(AzblobBackend, PrefixedAzblobConnection);
+
+impl StorageExport for AzblobBackend {
+    fn get_storage_path(&self, catalog: &str, schema: &str) -> (String, String) {
+        let azblob_path = format_uri(
+            "azblob",
+            &self.config.azblob_container,
+            &self.config.azblob_root,
+            &format!("{}/{}/", catalog, schema),
+        );
+
+        let mut connection_options = vec![
+            format!(
+                "ACCOUNT_NAME='{}'",
+                expose_optional_secret(&self.config.azblob_account_name)
+            ),
+            format!(
+                "ACCOUNT_KEY='{}'",
+                expose_optional_secret(&self.config.azblob_account_key)
+            ),
+        ];
+
+        if let Some(sas_token) = &self.config.azblob_sas_token {
+            connection_options.push(format!("SAS_TOKEN='{}'", sas_token));
+        }
+
+        let connection_str = format!(" CONNECTION ({})", connection_options.join(", "));
+        (azblob_path, connection_str)
+    }
+
+    fn format_output_path(&self, file_path: &str) -> String {
+        format_uri(
+            "azblob",
+            &self.config.azblob_container,
+            &self.config.azblob_root,
+            file_path,
+        )
+    }
+
+    fn mask_sensitive_info(&self, sql: &str) -> String {
+        mask_secrets(
+            sql.to_string(),
+            &[
+                expose_optional_secret(&self.config.azblob_account_name),
+                expose_optional_secret(&self.config.azblob_account_key),
+            ],
+        )
+    }
+}
+
+#[derive(Clone)]
+pub enum StorageType {
+    Fs(FsBackend),
+    S3(S3Backend),
+    Oss(OssBackend),
+    Gcs(GcsBackend),
+    Azblob(AzblobBackend),
+}
+
+impl StorageExport for StorageType {
+    fn get_storage_path(&self, catalog: &str, schema: &str) -> (String, String) {
+        match self {
+            StorageType::Fs(backend) => backend.get_storage_path(catalog, schema),
+            StorageType::S3(backend) => backend.get_storage_path(catalog, schema),
+            StorageType::Oss(backend) => backend.get_storage_path(catalog, schema),
+            StorageType::Gcs(backend) => backend.get_storage_path(catalog, schema),
+            StorageType::Azblob(backend) => backend.get_storage_path(catalog, schema),
+        }
+    }
+
+    fn format_output_path(&self, file_path: &str) -> String {
+        match self {
+            StorageType::Fs(backend) => backend.format_output_path(file_path),
+            StorageType::S3(backend) => backend.format_output_path(file_path),
+            StorageType::Oss(backend) => backend.format_output_path(file_path),
+            StorageType::Gcs(backend) => backend.format_output_path(file_path),
+            StorageType::Azblob(backend) => backend.format_output_path(file_path),
+        }
+    }
+
+    fn mask_sensitive_info(&self, sql: &str) -> String {
+        match self {
+            StorageType::Fs(backend) => backend.mask_sensitive_info(sql),
+            StorageType::S3(backend) => backend.mask_sensitive_info(sql),
+            StorageType::Oss(backend) => backend.mask_sensitive_info(sql),
+            StorageType::Gcs(backend) => backend.mask_sensitive_info(sql),
+            StorageType::Azblob(backend) => backend.mask_sensitive_info(sql),
+        }
+    }
+}
+
+impl StorageType {
+    /// Returns true if the storage backend is remote (not local filesystem).
+    pub fn is_remote_storage(&self) -> bool {
+        !matches!(self, StorageType::Fs(_))
+    }
+}

src/cli/src/error.rs

@@ -253,12 +253,6 @@ pub enum Error {
         error: ObjectStoreError,
     },
 
-    #[snafu(display("S3 config need be set"))]
-    S3ConfigNotSet {
-        #[snafu(implicit)]
-        location: Location,
-    },
-
     #[snafu(display("Output directory not set"))]
     OutputDirNotSet {
         #[snafu(implicit)]
@@ -364,9 +358,9 @@ impl ErrorExt for Error {
 
             Error::Other { source, .. } => source.status_code(),
             Error::OpenDal { .. } | Error::InitBackend { .. } => StatusCode::Internal,
-            Error::S3ConfigNotSet { .. }
-            | Error::OutputDirNotSet { .. }
-            | Error::EmptyStoreAddrs { .. } => StatusCode::InvalidArguments,
+            Error::OutputDirNotSet { .. } | Error::EmptyStoreAddrs { .. } => {
+                StatusCode::InvalidArguments
+            }
 
             Error::BuildRuntime { source, .. } => source.status_code(),
 

src/cmd/src/datanode/objbench.rs

@@ -145,6 +145,17 @@ impl ObjbenchCommand {
         let region_meta = extract_region_metadata(&self.source, &parquet_meta)?;
         let num_rows = parquet_meta.file_metadata().num_rows() as u64;
         let num_row_groups = parquet_meta.num_row_groups() as u64;
+        let max_row_group_uncompressed_size: u64 = parquet_meta
+            .row_groups()
+            .iter()
+            .map(|rg| {
+                rg.columns()
+                    .iter()
+                    .map(|c| c.uncompressed_size() as u64)
+                    .sum::<u64>()
+            })
+            .max()
+            .unwrap_or(0);
 
         println!(
             "{} Metadata loaded - rows: {}, size: {} bytes",
@@ -160,10 +171,11 @@ impl ObjbenchCommand {
             time_range: Default::default(),
             level: 0,
             file_size,
+            max_row_group_uncompressed_size,
             available_indexes: Default::default(),
             indexes: Default::default(),
             index_file_size: 0,
-            index_file_id: None,
+            index_version: 0,
             num_rows,
             num_row_groups,
             sequence: None,
@@ -564,7 +576,7 @@ fn new_noop_file_purger() -> FilePurgerRef {
     #[derive(Debug)]
     struct Noop;
     impl FilePurger for Noop {
-        fn remove_file(&self, _file_meta: FileMeta, _is_delete: bool) {}
+        fn remove_file(&self, _file_meta: FileMeta, _is_delete: bool, _index_outdated: bool) {}
     }
     Arc::new(Noop)
 }

src/cmd/src/frontend.rs

@@ -35,6 +35,7 @@ use common_meta::cache::{CacheRegistryBuilder, LayeredCacheRegistryBuilder};
 use common_meta::heartbeat::handler::HandlerGroupExecutor;
 use common_meta::heartbeat::handler::invalidate_table_cache::InvalidateCacheHandler;
 use common_meta::heartbeat::handler::parse_mailbox_message::ParseMailboxMessageHandler;
+use common_meta::heartbeat::handler::suspend::SuspendHandler;
 use common_query::prelude::set_default_prefix;
 use common_stat::ResourceStatImpl;
 use common_telemetry::info;
@@ -45,13 +46,13 @@ use frontend::frontend::Frontend;
 use frontend::heartbeat::HeartbeatTask;
 use frontend::instance::builder::FrontendBuilder;
 use frontend::server::Services;
-use meta_client::{MetaClientOptions, MetaClientType};
+use meta_client::{MetaClientOptions, MetaClientRef, MetaClientType};
 use plugins::frontend::context::{
     CatalogManagerConfigureContext, DistributedCatalogManagerConfigureContext,
 };
 use servers::addrs;
 use servers::grpc::GrpcOptions;
-use servers::tls::{TlsMode, TlsOption};
+use servers::tls::{TlsMode, TlsOption, merge_tls_option};
 use snafu::{OptionExt, ResultExt};
 use tracing_appender::non_blocking::WorkerGuard;
 
@@ -255,7 +256,7 @@ impl StartCommand {
 
         if let Some(addr) = &self.rpc_bind_addr {
             opts.grpc.bind_addr.clone_from(addr);
-            opts.grpc.tls = tls_opts.clone();
+            opts.grpc.tls = merge_tls_option(&opts.grpc.tls, tls_opts.clone());
         }
 
         if let Some(addr) = &self.rpc_server_addr {
@@ -290,13 +291,13 @@ impl StartCommand {
         if let Some(addr) = &self.mysql_addr {
             opts.mysql.enable = true;
             opts.mysql.addr.clone_from(addr);
-            opts.mysql.tls = tls_opts.clone();
+            opts.mysql.tls = merge_tls_option(&opts.mysql.tls, tls_opts.clone());
         }
 
         if let Some(addr) = &self.postgres_addr {
             opts.postgres.enable = true;
             opts.postgres.addr.clone_from(addr);
-            opts.postgres.tls = tls_opts;
+            opts.postgres.tls = merge_tls_option(&opts.postgres.tls, tls_opts.clone());
         }
 
         if let Some(enable) = self.influxdb_enable {
@@ -440,30 +441,13 @@ impl StartCommand {
         };
         let catalog_manager = builder.build();
 
-        let executor = HandlerGroupExecutor::new(vec![
-            Arc::new(ParseMailboxMessageHandler),
-            Arc::new(InvalidateCacheHandler::new(layered_cache_registry.clone())),
-        ]);
-
-        let mut resource_stat = ResourceStatImpl::default();
-        resource_stat.start_collect_cpu_usage();
-
-        let heartbeat_task = HeartbeatTask::new(
-            &opts,
-            meta_client.clone(),
-            opts.heartbeat.clone(),
-            Arc::new(executor),
-            Arc::new(resource_stat),
-        );
-        let heartbeat_task = Some(heartbeat_task);
-
         let instance = FrontendBuilder::new(
             opts.clone(),
             cached_meta_backend.clone(),
             layered_cache_registry.clone(),
             catalog_manager,
             client,
-            meta_client,
+            meta_client.clone(),
             process_manager,
         )
         .with_plugin(plugins.clone())
@@ -471,6 +455,9 @@ impl StartCommand {
         .try_build()
         .await
         .context(error::StartFrontendSnafu)?;
+
+        let heartbeat_task = Some(create_heartbeat_task(&opts, meta_client, &instance));
+
         let instance = Arc::new(instance);
 
         let servers = Services::new(opts, instance.clone(), plugins)
@@ -487,6 +474,28 @@ impl StartCommand {
     }
 }
 
+pub fn create_heartbeat_task(
+    options: &frontend::frontend::FrontendOptions,
+    meta_client: MetaClientRef,
+    instance: &frontend::instance::Instance,
+) -> HeartbeatTask {
+    let executor = Arc::new(HandlerGroupExecutor::new(vec![
+        Arc::new(ParseMailboxMessageHandler),
+        Arc::new(SuspendHandler::new(instance.suspend_state())),
+        Arc::new(InvalidateCacheHandler::new(
+            instance.cache_invalidator().clone(),
+        )),
+    ]));
+
+    let stat = {
+        let mut stat = ResourceStatImpl::default();
+        stat.start_collect_cpu_usage();
+        Arc::new(stat)
+    };
+
+    HeartbeatTask::new(options, meta_client, executor, stat)
+}
+
 #[cfg(test)]
 mod tests {
     use std::io::Write;

src/cmd/src/metasrv.rs

@@ -20,6 +20,7 @@ use async_trait::async_trait;
 use clap::Parser;
 use common_base::Plugins;
 use common_config::Configurable;
+use common_meta::distributed_time_constants::init_distributed_time_constants;
 use common_telemetry::info;
 use common_telemetry::logging::{DEFAULT_LOGGING_DIR, TracingOptions};
 use common_version::{short_version, verbose_version};
@@ -154,8 +155,6 @@ pub struct StartCommand {
     #[clap(short, long)]
     selector: Option<String>,
     #[clap(long)]
-    use_memory_store: Option<bool>,
-    #[clap(long)]
     enable_region_failover: Option<bool>,
     #[clap(long)]
     http_addr: Option<String>,
@@ -185,7 +184,6 @@ impl Debug for StartCommand {
             .field("store_addrs", &self.sanitize_store_addrs())
             .field("config_file", &self.config_file)
             .field("selector", &self.selector)
-            .field("use_memory_store", &self.use_memory_store)
             .field("enable_region_failover", &self.enable_region_failover)
             .field("http_addr", &self.http_addr)
             .field("http_timeout", &self.http_timeout)
@@ -267,10 +265,6 @@ impl StartCommand {
                 .context(error::UnsupportedSelectorTypeSnafu { selector_type })?;
         }
 
-        if let Some(use_memory_store) = self.use_memory_store {
-            opts.use_memory_store = use_memory_store;
-        }
-
         if let Some(enable_region_failover) = self.enable_region_failover {
             opts.enable_region_failover = enable_region_failover;
         }
@@ -327,6 +321,7 @@ impl StartCommand {
         log_versions(verbose_version(), short_version(), APP_NAME);
         maybe_activate_heap_profile(&opts.component.memory);
         create_resource_limit_metrics(APP_NAME);
+        init_distributed_time_constants(opts.component.heartbeat_interval);
 
         info!("Metasrv start command: {:#?}", self);
 
@@ -389,7 +384,6 @@ mod tests {
             server_addr = "127.0.0.1:3002"
             store_addr = "127.0.0.1:2379"
             selector = "LeaseBased"
-            use_memory_store = false
 
             [logging]
             level = "debug"
@@ -468,7 +462,6 @@ mod tests {
             server_addr = "127.0.0.1:3002"
             datanode_lease_secs = 15
             selector = "LeaseBased"
-            use_memory_store = false
 
             [http]
             addr = "127.0.0.1:4000"

src/cmd/src/standalone.rs

@@ -62,7 +62,7 @@ use plugins::frontend::context::{
     CatalogManagerConfigureContext, StandaloneCatalogManagerConfigureContext,
 };
 use plugins::standalone::context::DdlManagerConfigureContext;
-use servers::tls::{TlsMode, TlsOption};
+use servers::tls::{TlsMode, TlsOption, merge_tls_option};
 use snafu::ResultExt;
 use standalone::StandaloneInformationExtension;
 use standalone::options::StandaloneOptions;
@@ -293,19 +293,20 @@ impl StartCommand {
                     ),
                 }.fail();
             }
-            opts.grpc.bind_addr.clone_from(addr)
+            opts.grpc.bind_addr.clone_from(addr);
+            opts.grpc.tls = merge_tls_option(&opts.grpc.tls, tls_opts.clone());
         }
 
         if let Some(addr) = &self.mysql_addr {
             opts.mysql.enable = true;
             opts.mysql.addr.clone_from(addr);
-            opts.mysql.tls = tls_opts.clone();
+            opts.mysql.tls = merge_tls_option(&opts.mysql.tls, tls_opts.clone());
         }
 
         if let Some(addr) = &self.postgres_addr {
             opts.postgres.enable = true;
             opts.postgres.addr.clone_from(addr);
-            opts.postgres.tls = tls_opts;
+            opts.postgres.tls = merge_tls_option(&opts.postgres.tls, tls_opts.clone());
         }
 
         if self.influxdb_enable {
@@ -551,9 +552,8 @@ impl StartCommand {
         let grpc_handler = fe_instance.clone() as Arc<dyn GrpcQueryHandlerWithBoxedError>;
         let weak_grpc_handler = Arc::downgrade(&grpc_handler);
         frontend_instance_handler
-            .lock()
-            .unwrap()
-            .replace(weak_grpc_handler);
+            .set_handler(weak_grpc_handler)
+            .await;
 
         // set the frontend invoker for flownode
         let flow_streaming_engine = flownode.flow_engine().streaming_engine();
@@ -765,7 +765,6 @@ mod tests {
             user_provider: Some("static_user_provider:cmd:test=test".to_string()),
             mysql_addr: Some("127.0.0.1:4002".to_string()),
             postgres_addr: Some("127.0.0.1:4003".to_string()),
-            tls_watch: true,
             ..Default::default()
         };
 
@@ -782,8 +781,6 @@ mod tests {
 
         assert_eq!("./greptimedb_data/test/logs", opts.logging.dir);
         assert_eq!("debug", opts.logging.level.unwrap());
-        assert!(opts.mysql.tls.watch);
-        assert!(opts.postgres.tls.watch);
     }
 
     #[test]

src/common/config/Cargo.toml

@@ -11,8 +11,10 @@ workspace = true
 common-base.workspace = true
 common-error.workspace = true
 common-macro.workspace = true
+common-telemetry.workspace = true
 config.workspace = true
 humantime-serde.workspace = true
+notify.workspace = true
 object-store.workspace = true
 serde.workspace = true
 serde_json.workspace = true

src/common/config/src/error.rs

@@ -49,14 +49,31 @@ pub enum Error {
         #[snafu(implicit)]
         location: Location,
     },
+
+    #[snafu(display("Failed to watch file: {}", path))]
+    FileWatch {
+        path: String,
+        #[snafu(source)]
+        error: notify::Error,
+        #[snafu(implicit)]
+        location: Location,
+    },
+
+    #[snafu(display("Invalid path '{}': expected a file, not a directory", path))]
+    InvalidPath {
+        path: String,
+        #[snafu(implicit)]
+        location: Location,
+    },
 }
 
 impl ErrorExt for Error {
     fn status_code(&self) -> StatusCode {
         match self {
-            Error::TomlFormat { .. } | Error::LoadLayeredConfig { .. } => {
-                StatusCode::InvalidArguments
-            }
+            Error::TomlFormat { .. }
+            | Error::LoadLayeredConfig { .. }
+            | Error::FileWatch { .. }
+            | Error::InvalidPath { .. } => StatusCode::InvalidArguments,
             Error::SerdeJson { .. } => StatusCode::Unexpected,
         }
     }

src/common/config/src/file_watcher.rs

@@ -0,0 +1,277 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Common file watching utilities for configuration hot-reloading.
+//!
+//! This module provides a generic file watcher that can be used to watch
+//! files for changes and trigger callbacks when changes occur.
+//!
+//! The watcher monitors the parent directory of each file rather than the
+//! file itself. This ensures that file deletions and recreations are properly
+//! tracked, which is common with editors that use atomic saves or when
+//! configuration files are replaced.
+
+use std::collections::HashSet;
+use std::path::{Path, PathBuf};
+use std::sync::mpsc::channel;
+
+use common_telemetry::{error, info, warn};
+use notify::{EventKind, RecursiveMode, Watcher};
+use snafu::ResultExt;
+
+use crate::error::{FileWatchSnafu, InvalidPathSnafu, Result};
+
+/// Configuration for the file watcher behavior.
+#[derive(Debug, Clone, Default)]
+pub struct FileWatcherConfig {
+    /// Whether to include Remove events in addition to Modify and Create.
+    pub include_remove_events: bool,
+}
+
+impl FileWatcherConfig {
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    pub fn include_remove_events(mut self) -> Self {
+        self.include_remove_events = true;
+        self
+    }
+}
+
+/// A builder for creating file watchers with flexible configuration.
+///
+/// The watcher monitors the parent directory of each file to handle file
+/// deletion and recreation properly. Events are filtered to only trigger
+/// callbacks for the specific files being watched.
+pub struct FileWatcherBuilder {
+    config: FileWatcherConfig,
+    /// Canonicalized paths of files to watch.
+    file_paths: Vec<PathBuf>,
+}
+
+impl FileWatcherBuilder {
+    /// Create a new builder with default configuration.
+    pub fn new() -> Self {
+        Self {
+            config: FileWatcherConfig::default(),
+            file_paths: Vec::new(),
+        }
+    }
+
+    /// Set the watcher configuration.
+    pub fn config(mut self, config: FileWatcherConfig) -> Self {
+        self.config = config;
+        self
+    }
+
+    /// Add a file path to watch.
+    ///
+    /// Returns an error if the path is a directory.
+    /// The path is canonicalized for reliable comparison with events.
+    pub fn watch_path<P: AsRef<Path>>(mut self, path: P) -> Result<Self> {
+        let path = path.as_ref();
+        snafu::ensure!(
+            path.is_file(),
+            InvalidPathSnafu {
+                path: path.display().to_string(),
+            }
+        );
+
+        self.file_paths.push(path.to_path_buf());
+        Ok(self)
+    }
+
+    /// Add multiple file paths to watch.
+    ///
+    /// Returns an error if any path is a directory.
+    pub fn watch_paths<P: AsRef<Path>, I: IntoIterator<Item = P>>(
+        mut self,
+        paths: I,
+    ) -> Result<Self> {
+        for path in paths {
+            self = self.watch_path(path)?;
+        }
+        Ok(self)
+    }
+
+    /// Build and spawn the file watcher with the given callback.
+    ///
+    /// The callback is invoked when relevant file events are detected for
+    /// the watched files. The watcher monitors the parent directories to
+    /// handle file deletion and recreation properly.
+    ///
+    /// The spawned watcher thread runs for the lifetime of the process.
+    pub fn spawn<F>(self, callback: F) -> Result<()>
+    where
+        F: Fn() + Send + 'static,
+    {
+        let (tx, rx) = channel::<notify::Result<notify::Event>>();
+        let mut watcher =
+            notify::recommended_watcher(tx).context(FileWatchSnafu { path: "<none>" })?;
+
+        // Collect unique parent directories to watch
+        let mut watched_dirs: HashSet<PathBuf> = HashSet::new();
+        for file_path in &self.file_paths {
+            if let Some(parent) = file_path.parent()
+                && watched_dirs.insert(parent.to_path_buf())
+            {
+                watcher
+                    .watch(parent, RecursiveMode::NonRecursive)
+                    .context(FileWatchSnafu {
+                        path: parent.display().to_string(),
+                    })?;
+            }
+        }
+
+        let config = self.config;
+
+        info!(
+            "Spawning file watcher for paths: {:?} (watching parent directories)",
+            self.file_paths
+                .iter()
+                .map(|p| p.display().to_string())
+                .collect::<Vec<_>>()
+        );
+
+        std::thread::spawn(move || {
+            // Keep watcher alive in the thread
+            let _watcher = watcher;
+
+            while let Ok(res) = rx.recv() {
+                match res {
+                    Ok(event) => {
+                        if !is_relevant_event(&event.kind, &config) {
+                            continue;
+                        }
+
+                        info!(?event.kind, ?event.paths, "Detected folder change");
+                        callback();
+                    }
+                    Err(err) => {
+                        warn!("File watcher error: {}", err);
+                    }
+                }
+            }
+
+            error!("File watcher channel closed unexpectedly");
+        });
+
+        Ok(())
+    }
+}
+
+impl Default for FileWatcherBuilder {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+/// Check if an event kind is relevant based on the configuration.
+fn is_relevant_event(kind: &EventKind, config: &FileWatcherConfig) -> bool {
+    match kind {
+        EventKind::Modify(_) | EventKind::Create(_) => true,
+        EventKind::Remove(_) => config.include_remove_events,
+        _ => false,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+    use std::sync::atomic::{AtomicUsize, Ordering};
+    use std::time::Duration;
+
+    use common_test_util::temp_dir::create_temp_dir;
+
+    use super::*;
+
+    #[test]
+    fn test_file_watcher_detects_changes() {
+        common_telemetry::init_default_ut_logging();
+
+        let dir = create_temp_dir("test_file_watcher");
+        let file_path = dir.path().join("test_file.txt");
+
+        // Create initial file
+        std::fs::write(&file_path, "initial content").unwrap();
+
+        let counter = Arc::new(AtomicUsize::new(0));
+        let counter_clone = counter.clone();
+
+        FileWatcherBuilder::new()
+            .watch_path(&file_path)
+            .unwrap()
+            .config(FileWatcherConfig::new())
+            .spawn(move || {
+                counter_clone.fetch_add(1, Ordering::SeqCst);
+            })
+            .unwrap();
+
+        // Give watcher time to start
+        std::thread::sleep(Duration::from_millis(100));
+
+        // Modify the file
+        std::fs::write(&file_path, "modified content").unwrap();
+
+        // Wait for the event to be processed
+        std::thread::sleep(Duration::from_millis(500));
+
+        assert!(
+            counter.load(Ordering::SeqCst) >= 1,
+            "Watcher should have detected at least one change"
+        );
+    }
+
+    #[test]
+    fn test_file_watcher_detects_delete_and_recreate() {
+        common_telemetry::init_default_ut_logging();
+
+        let dir = create_temp_dir("test_file_watcher_recreate");
+        let file_path = dir.path().join("test_file.txt");
+
+        // Create initial file
+        std::fs::write(&file_path, "initial content").unwrap();
+
+        let counter = Arc::new(AtomicUsize::new(0));
+        let counter_clone = counter.clone();
+
+        FileWatcherBuilder::new()
+            .watch_path(&file_path)
+            .unwrap()
+            .config(FileWatcherConfig::new())
+            .spawn(move || {
+                counter_clone.fetch_add(1, Ordering::SeqCst);
+            })
+            .unwrap();
+
+        // Give watcher time to start
+        std::thread::sleep(Duration::from_millis(100));
+
+        // Delete the file
+        std::fs::remove_file(&file_path).unwrap();
+        std::thread::sleep(Duration::from_millis(100));
+
+        // Recreate the file - this should still be detected because we watch the directory
+        std::fs::write(&file_path, "recreated content").unwrap();
+
+        // Wait for the event to be processed
+        std::thread::sleep(Duration::from_millis(500));
+
+        assert!(
+            counter.load(Ordering::SeqCst) >= 1,
+            "Watcher should have detected file recreation"
+        );
+    }
+}

src/common/config/src/lib.rs

@@ -14,6 +14,7 @@
 
 pub mod config;
 pub mod error;
+pub mod file_watcher;
 
 use std::time::Duration;
 

src/common/datasource/src/object_store/s3.rs

@@ -27,6 +27,7 @@ const SECRET_ACCESS_KEY: &str = "secret_access_key";
 const SESSION_TOKEN: &str = "session_token";
 const REGION: &str = "region";
 const ENABLE_VIRTUAL_HOST_STYLE: &str = "enable_virtual_host_style";
+const DISABLE_EC2_METADATA: &str = "disable_ec2_metadata";
 
 pub fn is_supported_in_s3(key: &str) -> bool {
     [
@@ -36,6 +37,7 @@ pub fn is_supported_in_s3(key: &str) -> bool {
         SESSION_TOKEN,
         REGION,
         ENABLE_VIRTUAL_HOST_STYLE,
+        DISABLE_EC2_METADATA,
     ]
     .contains(&key)
 }
@@ -82,6 +84,21 @@ pub fn build_s3_backend(
         }
     }
 
+    if let Some(disable_str) = connection.get(DISABLE_EC2_METADATA) {
+        let disable = disable_str.as_str().parse::<bool>().map_err(|e| {
+            error::InvalidConnectionSnafu {
+                msg: format!(
+                    "failed to parse the option {}={}, {}",
+                    DISABLE_EC2_METADATA, disable_str, e
+                ),
+            }
+            .build()
+        })?;
+        if disable {
+            builder = builder.disable_ec2_metadata();
+        }
+    }
+
     // TODO(weny): Consider finding a better way to eliminate duplicate code.
     Ok(ObjectStore::new(builder)
         .context(error::BuildBackendSnafu)?
@@ -109,6 +126,7 @@ mod tests {
         assert!(is_supported_in_s3(SESSION_TOKEN));
         assert!(is_supported_in_s3(REGION));
         assert!(is_supported_in_s3(ENABLE_VIRTUAL_HOST_STYLE));
+        assert!(is_supported_in_s3(DISABLE_EC2_METADATA));
         assert!(!is_supported_in_s3("foo"))
     }
 }

src/common/error/src/lib.rs

@@ -21,6 +21,8 @@ pub mod status_code;
 use http::{HeaderMap, HeaderValue};
 pub use snafu;
 
+use crate::status_code::StatusCode;
+
 // HACK - these headers are here for shared in gRPC services. For common HTTP headers,
 // please define in `src/servers/src/http/header.rs`.
 pub const GREPTIME_DB_HEADER_ERROR_CODE: &str = "x-greptime-err-code";
@@ -46,6 +48,29 @@ pub fn from_err_code_msg_to_header(code: u32, msg: &str) -> HeaderMap {
     header
 }
 
+/// Extract [StatusCode] and error message from [HeaderMap], if any.
+///
+/// Note that if the [StatusCode] is illegal, for example, a random number that is not pre-defined
+/// as a [StatusCode], the result is still `None`.
+pub fn from_header_to_err_code_msg(headers: &HeaderMap) -> Option<(StatusCode, &str)> {
+    let code = headers
+        .get(GREPTIME_DB_HEADER_ERROR_CODE)
+        .and_then(|value| {
+            value
+                .to_str()
+                .ok()
+                .and_then(|x| x.parse::<u32>().ok())
+                .and_then(StatusCode::from_u32)
+        });
+    let msg = headers
+        .get(GREPTIME_DB_HEADER_ERROR_MSG)
+        .and_then(|x| x.to_str().ok());
+    match (code, msg) {
+        (Some(code), Some(msg)) => Some((code, msg)),
+        _ => None,
+    }
+}
+
 /// Returns the external root cause of the source error (exclude the current error).
 pub fn root_source(err: &dyn std::error::Error) -> Option<&dyn std::error::Error> {
     // There are some divergence about the behavior of the `sources()` API

src/common/error/src/status_code.rs

@@ -42,6 +42,8 @@ pub enum StatusCode {
     External = 1007,
     /// The request is deadline exceeded (typically server-side).
     DeadlineExceeded = 1008,
+    /// Service got suspended for various reason. For example, resources exceed limit.
+    Suspended = 1009,
     // ====== End of common status code ================
 
     // ====== Begin of SQL related status code =========
@@ -175,7 +177,8 @@ impl StatusCode {
             | StatusCode::AccessDenied
             | StatusCode::PermissionDenied
             | StatusCode::RequestOutdated
-            | StatusCode::External => false,
+            | StatusCode::External
+            | StatusCode::Suspended => false,
         }
     }
 
@@ -223,7 +226,8 @@ impl StatusCode {
             | StatusCode::InvalidAuthHeader
             | StatusCode::AccessDenied
             | StatusCode::PermissionDenied
-            | StatusCode::RequestOutdated => false,
+            | StatusCode::RequestOutdated
+            | StatusCode::Suspended => false,
         }
     }
 
@@ -347,7 +351,8 @@ pub fn status_to_tonic_code(status_code: StatusCode) -> Code {
         | StatusCode::RegionNotReady => Code::Unavailable,
         StatusCode::RuntimeResourcesExhausted
         | StatusCode::RateLimited
-        | StatusCode::RegionBusy => Code::ResourceExhausted,
+        | StatusCode::RegionBusy
+        | StatusCode::Suspended => Code::ResourceExhausted,
         StatusCode::UnsupportedPasswordType
         | StatusCode::UserPasswordMismatch
         | StatusCode::AuthHeaderNotFound

src/common/function/Cargo.toml

@@ -19,7 +19,7 @@ arc-swap = "1.0"
 arrow.workspace = true
 arrow-schema.workspace = true
 async-trait.workspace = true
-bincode = "1.3"
+bincode = "=1.3.3"
 catalog.workspace = true
 chrono.workspace = true
 common-base.workspace = true
@@ -39,7 +39,7 @@ datafusion-functions-aggregate-common.workspace = true
 datafusion-pg-catalog.workspace = true
 datafusion-physical-expr.workspace = true
 datatypes.workspace = true
-derive_more = { version = "1", default-features = false, features = ["display"] }
+derive_more.workspace = true
 geo = { version = "0.29", optional = true }
 geo-types = { version = "0.7", optional = true }
 geohash = { version = "0.13", optional = true }

src/common/function/src/scalars/geo/relation.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::fmt::Display;
 use std::sync::Arc;
 
 use datafusion_common::arrow::array::{Array, AsArray, BooleanBuilder};

src/common/function/src/system/pg_catalog.rs

@@ -387,6 +387,8 @@ impl PGCatalogFunction {
         registry.register(pg_catalog::create_pg_stat_get_numscans());
         registry.register(pg_catalog::create_pg_get_constraintdef());
         registry.register(pg_catalog::create_pg_get_partition_ancestors_udf());
+        registry.register(pg_catalog::quote_ident_udf::create_quote_ident_udf());
+        registry.register(pg_catalog::quote_ident_udf::create_parse_ident_udf());
         registry.register_scalar(ObjDescriptionFunction::new());
         registry.register_scalar(ColDescriptionFunction::new());
         registry.register_scalar(ShobjDescriptionFunction::new());

src/common/grpc/Cargo.toml

@@ -12,6 +12,7 @@ api.workspace = true
 arrow-flight.workspace = true
 bytes.workspace = true
 common-base.workspace = true
+common-config.workspace = true
 common-error.workspace = true
 common-macro.workspace = true
 common-recordbatch.workspace = true
@@ -23,7 +24,6 @@ datatypes.workspace = true
 flatbuffers = "25.2"
 hyper.workspace = true
 lazy_static.workspace = true
-notify.workspace = true
 prost.workspace = true
 serde.workspace = true
 serde_json.workspace = true

src/common/grpc/src/error.rs

@@ -38,11 +38,10 @@ pub enum Error {
         location: Location,
     },
 
-    #[snafu(display("Failed to watch config file path: {}", path))]
+    #[snafu(display("Failed to watch config file"))]
     FileWatch {
-        path: String,
         #[snafu(source)]
-        error: notify::Error,
+        source: common_config::error::Error,
         #[snafu(implicit)]
         location: Location,
     },

src/common/grpc/src/reloadable_tls.rs

@@ -15,11 +15,10 @@
 use std::path::Path;
 use std::result::Result as StdResult;
 use std::sync::atomic::{AtomicUsize, Ordering};
-use std::sync::mpsc::channel;
 use std::sync::{Arc, RwLock};
 
+use common_config::file_watcher::{FileWatcherBuilder, FileWatcherConfig};
 use common_telemetry::{error, info};
-use notify::{EventKind, RecursiveMode, Watcher};
 use snafu::ResultExt;
 
 use crate::error::{FileWatchSnafu, Result};
@@ -119,45 +118,28 @@ where
         return Ok(());
     }
 
+    let watch_paths: Vec<_> = tls_config
+        .get_tls_option()
+        .watch_paths()
+        .iter()
+        .map(|p| p.to_path_buf())
+        .collect();
+
     let tls_config_for_watcher = tls_config.clone();
 
-    let (tx, rx) = channel::<notify::Result<notify::Event>>();
-    let mut watcher = notify::recommended_watcher(tx).context(FileWatchSnafu { path: "<none>" })?;
-
-    // Watch all paths returned by the TlsConfigLoader
-    for path in tls_config.get_tls_option().watch_paths() {
-        watcher
-            .watch(path, RecursiveMode::NonRecursive)
-            .with_context(|_| FileWatchSnafu {
-                path: path.display().to_string(),
-            })?;
-    }
-
-    info!("Spawning background task for watching TLS cert/key file changes");
-    std::thread::spawn(move || {
-        let _watcher = watcher;
-        loop {
-            match rx.recv() {
-                Ok(Ok(event)) => {
-                    if let EventKind::Modify(_) | EventKind::Create(_) = event.kind {
-                        info!("Detected TLS cert/key file change: {:?}", event);
+    FileWatcherBuilder::new()
+        .watch_paths(&watch_paths)
+        .context(FileWatchSnafu)?
+        .config(FileWatcherConfig::new())
+        .spawn(move || {
             if let Err(err) = tls_config_for_watcher.reload() {
                 error!("Failed to reload TLS config: {}", err);
             } else {
                 info!("Reloaded TLS cert/key file successfully.");
                 on_reload();
             }
-                    }
-                }
-                Ok(Err(err)) => {
-                    error!("Failed to watch TLS cert/key file: {}", err);
-                }
-                Err(err) => {
-                    error!("TLS cert/key file watcher channel closed: {}", err);
-                }
-            }
-        }
-    });
+        })
+        .context(FileWatchSnafu)?;
 
     Ok(())
 }

src/common/memory-manager/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "common-memory-manager"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+
+[lints]
+workspace = true
+
+[dependencies]
+common-error = { workspace = true }
+common-macro = { workspace = true }
+common-telemetry = { workspace = true }
+humantime = { workspace = true }
+serde = { workspace = true }
+snafu = { workspace = true }
+tokio = { workspace = true, features = ["sync"] }
+
+[dev-dependencies]
+tokio = { workspace = true, features = ["rt", "macros"] }

src/common/memory-manager/src/error.rs

@@ -0,0 +1,63 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::any::Any;
+use std::time::Duration;
+
+use common_error::ext::ErrorExt;
+use common_error::status_code::StatusCode;
+use common_macro::stack_trace_debug;
+use snafu::Snafu;
+
+pub type Result<T> = std::result::Result<T, Error>;
+
+#[derive(Snafu)]
+#[snafu(visibility(pub))]
+#[stack_trace_debug]
+pub enum Error {
+    #[snafu(display(
+        "Memory limit exceeded: requested {requested_bytes} bytes, limit {limit_bytes} bytes"
+    ))]
+    MemoryLimitExceeded {
+        requested_bytes: u64,
+        limit_bytes: u64,
+    },
+
+    #[snafu(display("Memory semaphore unexpectedly closed"))]
+    MemorySemaphoreClosed,
+
+    #[snafu(display(
+        "Timeout waiting for memory quota: requested {requested_bytes} bytes, waited {waited:?}"
+    ))]
+    MemoryAcquireTimeout {
+        requested_bytes: u64,
+        waited: Duration,
+    },
+}
+
+impl ErrorExt for Error {
+    fn status_code(&self) -> StatusCode {
+        use Error::*;
+
+        match self {
+            MemoryLimitExceeded { .. } => StatusCode::RuntimeResourcesExhausted,
+            MemorySemaphoreClosed => StatusCode::Unexpected,
+            MemoryAcquireTimeout { .. } => StatusCode::RuntimeResourcesExhausted,
+        }
+    }
+
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+}

src/common/memory-manager/src/granularity.rs

@@ -0,0 +1,168 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::fmt;
+
+/// Memory permit granularity for different use cases.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+pub enum PermitGranularity {
+    /// 1 KB per permit
+    ///
+    /// Use for:
+    /// - HTTP/gRPC request limiting (small, high-concurrency operations)
+    /// - Small batch operations
+    /// - Scenarios requiring fine-grained fairness
+    Kilobyte,
+
+    /// 1 MB per permit (default)
+    ///
+    /// Use for:
+    /// - Query execution memory management
+    /// - Compaction memory control
+    /// - Large, long-running operations
+    #[default]
+    Megabyte,
+}
+
+impl PermitGranularity {
+    /// Returns the number of bytes per permit.
+    #[inline]
+    pub const fn bytes(self) -> u64 {
+        match self {
+            Self::Kilobyte => 1024,
+            Self::Megabyte => 1024 * 1024,
+        }
+    }
+
+    /// Returns a human-readable string representation.
+    pub const fn as_str(self) -> &'static str {
+        match self {
+            Self::Kilobyte => "1KB",
+            Self::Megabyte => "1MB",
+        }
+    }
+
+    /// Converts bytes to permits based on this granularity.
+    ///
+    /// Rounds up to ensure the requested bytes are fully covered.
+    /// Clamped to Semaphore::MAX_PERMITS.
+    #[inline]
+    pub fn bytes_to_permits(self, bytes: u64) -> u32 {
+        use tokio::sync::Semaphore;
+
+        let granularity_bytes = self.bytes();
+        bytes
+            .saturating_add(granularity_bytes - 1)
+            .saturating_div(granularity_bytes)
+            .min(Semaphore::MAX_PERMITS as u64)
+            .min(u32::MAX as u64) as u32
+    }
+
+    /// Converts permits to bytes based on this granularity.
+    #[inline]
+    pub fn permits_to_bytes(self, permits: u32) -> u64 {
+        (permits as u64).saturating_mul(self.bytes())
+    }
+}
+
+impl fmt::Display for PermitGranularity {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.as_str())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_bytes_to_permits_kilobyte() {
+        let granularity = PermitGranularity::Kilobyte;
+
+        // Exact multiples
+        assert_eq!(granularity.bytes_to_permits(1024), 1);
+        assert_eq!(granularity.bytes_to_permits(2048), 2);
+        assert_eq!(granularity.bytes_to_permits(10 * 1024), 10);
+
+        // Rounds up
+        assert_eq!(granularity.bytes_to_permits(1), 1);
+        assert_eq!(granularity.bytes_to_permits(1025), 2);
+        assert_eq!(granularity.bytes_to_permits(2047), 2);
+    }
+
+    #[test]
+    fn test_bytes_to_permits_megabyte() {
+        let granularity = PermitGranularity::Megabyte;
+
+        // Exact multiples
+        assert_eq!(granularity.bytes_to_permits(1024 * 1024), 1);
+        assert_eq!(granularity.bytes_to_permits(2 * 1024 * 1024), 2);
+
+        // Rounds up
+        assert_eq!(granularity.bytes_to_permits(1), 1);
+        assert_eq!(granularity.bytes_to_permits(1024), 1);
+        assert_eq!(granularity.bytes_to_permits(1024 * 1024 + 1), 2);
+    }
+
+    #[test]
+    fn test_bytes_to_permits_zero_bytes() {
+        assert_eq!(PermitGranularity::Kilobyte.bytes_to_permits(0), 0);
+        assert_eq!(PermitGranularity::Megabyte.bytes_to_permits(0), 0);
+    }
+
+    #[test]
+    fn test_bytes_to_permits_clamps_to_maximum() {
+        use tokio::sync::Semaphore;
+
+        let max_permits = (Semaphore::MAX_PERMITS as u64).min(u32::MAX as u64) as u32;
+
+        assert_eq!(
+            PermitGranularity::Kilobyte.bytes_to_permits(u64::MAX),
+            max_permits
+        );
+        assert_eq!(
+            PermitGranularity::Megabyte.bytes_to_permits(u64::MAX),
+            max_permits
+        );
+    }
+
+    #[test]
+    fn test_permits_to_bytes() {
+        assert_eq!(PermitGranularity::Kilobyte.permits_to_bytes(1), 1024);
+        assert_eq!(PermitGranularity::Kilobyte.permits_to_bytes(10), 10 * 1024);
+
+        assert_eq!(PermitGranularity::Megabyte.permits_to_bytes(1), 1024 * 1024);
+        assert_eq!(
+            PermitGranularity::Megabyte.permits_to_bytes(10),
+            10 * 1024 * 1024
+        );
+    }
+
+    #[test]
+    fn test_round_trip_conversion() {
+        // Kilobyte: bytes -> permits -> bytes (should round up)
+        let kb = PermitGranularity::Kilobyte;
+        let permits = kb.bytes_to_permits(1500);
+        let bytes = kb.permits_to_bytes(permits);
+        assert!(bytes >= 1500); // Must cover original request
+        assert_eq!(bytes, 2048); // 2KB
+
+        // Megabyte: bytes -> permits -> bytes (should round up)
+        let mb = PermitGranularity::Megabyte;
+        let permits = mb.bytes_to_permits(1500);
+        let bytes = mb.permits_to_bytes(permits);
+        assert!(bytes >= 1500);
+        assert_eq!(bytes, 1024 * 1024); // 1MB
+    }
+}

src/common/memory-manager/src/guard.rs

@@ -0,0 +1,141 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::{fmt, mem};
+
+use common_telemetry::debug;
+use tokio::sync::{OwnedSemaphorePermit, TryAcquireError};
+
+use crate::manager::{MemoryMetrics, MemoryQuota};
+
+/// Guard representing a slice of reserved memory.
+pub struct MemoryGuard<M: MemoryMetrics> {
+    pub(crate) state: GuardState<M>,
+}
+
+pub(crate) enum GuardState<M: MemoryMetrics> {
+    Unlimited,
+    Limited {
+        permit: OwnedSemaphorePermit,
+        quota: MemoryQuota<M>,
+    },
+}
+
+impl<M: MemoryMetrics> MemoryGuard<M> {
+    pub(crate) fn unlimited() -> Self {
+        Self {
+            state: GuardState::Unlimited,
+        }
+    }
+
+    pub(crate) fn limited(permit: OwnedSemaphorePermit, quota: MemoryQuota<M>) -> Self {
+        Self {
+            state: GuardState::Limited { permit, quota },
+        }
+    }
+
+    /// Returns granted quota in bytes.
+    pub fn granted_bytes(&self) -> u64 {
+        match &self.state {
+            GuardState::Unlimited => 0,
+            GuardState::Limited { permit, quota } => {
+                quota.permits_to_bytes(permit.num_permits() as u32)
+            }
+        }
+    }
+
+    /// Tries to allocate additional memory during task execution.
+    ///
+    /// On success, merges the new memory into this guard and returns true.
+    /// On failure, returns false and leaves this guard unchanged.
+    pub fn request_additional(&mut self, bytes: u64) -> bool {
+        match &mut self.state {
+            GuardState::Unlimited => true,
+            GuardState::Limited { permit, quota } => {
+                if bytes == 0 {
+                    return true;
+                }
+
+                let additional_permits = quota.bytes_to_permits(bytes);
+
+                match quota
+                    .semaphore
+                    .clone()
+                    .try_acquire_many_owned(additional_permits)
+                {
+                    Ok(additional_permit) => {
+                        permit.merge(additional_permit);
+                        quota.update_in_use_metric();
+                        debug!("Allocated additional {} bytes", bytes);
+                        true
+                    }
+                    Err(TryAcquireError::NoPermits) | Err(TryAcquireError::Closed) => {
+                        quota.metrics.inc_rejected("request_additional");
+                        false
+                    }
+                }
+            }
+        }
+    }
+
+    /// Releases a portion of granted memory back to the pool early,
+    /// before the guard is dropped.
+    ///
+    /// Returns true if the release succeeds or is a no-op; false if the request exceeds granted.
+    pub fn early_release_partial(&mut self, bytes: u64) -> bool {
+        match &mut self.state {
+            GuardState::Unlimited => true,
+            GuardState::Limited { permit, quota } => {
+                if bytes == 0 {
+                    return true;
+                }
+
+                let release_permits = quota.bytes_to_permits(bytes);
+
+                match permit.split(release_permits as usize) {
+                    Some(released_permit) => {
+                        let released_bytes =
+                            quota.permits_to_bytes(released_permit.num_permits() as u32);
+                        drop(released_permit);
+                        quota.update_in_use_metric();
+                        debug!("Early released {} bytes from memory guard", released_bytes);
+                        true
+                    }
+                    None => false,
+                }
+            }
+        }
+    }
+}
+
+impl<M: MemoryMetrics> Drop for MemoryGuard<M> {
+    fn drop(&mut self) {
+        if let GuardState::Limited { permit, quota } =
+            mem::replace(&mut self.state, GuardState::Unlimited)
+        {
+            let bytes = quota.permits_to_bytes(permit.num_permits() as u32);
+            drop(permit);
+            quota.update_in_use_metric();
+            debug!("Released memory: {} bytes", bytes);
+        }
+    }
+}
+
+impl<M: MemoryMetrics> fmt::Debug for MemoryGuard<M> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("MemoryGuard")
+            .field("granted_bytes", &self.granted_bytes())
+            .finish()
+    }
+}

src/common/memory-manager/src/lib.rs

@@ -0,0 +1,49 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Generic memory management for resource-constrained operations.
+//!
+//! This crate provides a reusable memory quota system based on semaphores,
+//! allowing different subsystems (compaction, flush, index build, etc.) to
+//! share the same allocation logic while using their own metrics.
+
+mod error;
+mod granularity;
+mod guard;
+mod manager;
+mod policy;
+
+#[cfg(test)]
+mod tests;
+
+pub use error::{Error, Result};
+pub use granularity::PermitGranularity;
+pub use guard::MemoryGuard;
+pub use manager::{MemoryManager, MemoryMetrics};
+pub use policy::{DEFAULT_MEMORY_WAIT_TIMEOUT, OnExhaustedPolicy};
+
+/// No-op metrics implementation for testing.
+#[derive(Clone, Copy, Debug, Default)]
+pub struct NoOpMetrics;
+
+impl MemoryMetrics for NoOpMetrics {
+    #[inline(always)]
+    fn set_limit(&self, _: i64) {}
+
+    #[inline(always)]
+    fn set_in_use(&self, _: i64) {}
+
+    #[inline(always)]
+    fn inc_rejected(&self, _: &str) {}
+}

src/common/memory-manager/src/manager.rs

@@ -0,0 +1,222 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::sync::Arc;
+
+use snafu::ensure;
+use tokio::sync::{Semaphore, TryAcquireError};
+
+use crate::error::{
+    MemoryAcquireTimeoutSnafu, MemoryLimitExceededSnafu, MemorySemaphoreClosedSnafu, Result,
+};
+use crate::granularity::PermitGranularity;
+use crate::guard::MemoryGuard;
+use crate::policy::OnExhaustedPolicy;
+
+/// Trait for recording memory usage metrics.
+pub trait MemoryMetrics: Clone + Send + Sync + 'static {
+    fn set_limit(&self, bytes: i64);
+    fn set_in_use(&self, bytes: i64);
+    fn inc_rejected(&self, reason: &str);
+}
+
+/// Generic memory manager for quota-controlled operations.
+#[derive(Clone)]
+pub struct MemoryManager<M: MemoryMetrics> {
+    quota: Option<MemoryQuota<M>>,
+}
+
+impl<M: MemoryMetrics + Default> Default for MemoryManager<M> {
+    fn default() -> Self {
+        Self::new(0, M::default())
+    }
+}
+
+#[derive(Clone)]
+pub(crate) struct MemoryQuota<M: MemoryMetrics> {
+    pub(crate) semaphore: Arc<Semaphore>,
+    pub(crate) limit_permits: u32,
+    pub(crate) granularity: PermitGranularity,
+    pub(crate) metrics: M,
+}
+
+impl<M: MemoryMetrics> MemoryManager<M> {
+    /// Creates a new memory manager with the given limit in bytes.
+    /// `limit_bytes = 0` disables the limit.
+    pub fn new(limit_bytes: u64, metrics: M) -> Self {
+        Self::with_granularity(limit_bytes, PermitGranularity::default(), metrics)
+    }
+
+    /// Creates a new memory manager with specified granularity.
+    pub fn with_granularity(limit_bytes: u64, granularity: PermitGranularity, metrics: M) -> Self {
+        if limit_bytes == 0 {
+            metrics.set_limit(0);
+            return Self { quota: None };
+        }
+
+        let limit_permits = granularity.bytes_to_permits(limit_bytes);
+        let limit_aligned_bytes = granularity.permits_to_bytes(limit_permits);
+        metrics.set_limit(limit_aligned_bytes as i64);
+
+        Self {
+            quota: Some(MemoryQuota {
+                semaphore: Arc::new(Semaphore::new(limit_permits as usize)),
+                limit_permits,
+                granularity,
+                metrics,
+            }),
+        }
+    }
+
+    /// Returns the configured limit in bytes (0 if unlimited).
+    pub fn limit_bytes(&self) -> u64 {
+        self.quota
+            .as_ref()
+            .map(|quota| quota.permits_to_bytes(quota.limit_permits))
+            .unwrap_or(0)
+    }
+
+    /// Returns currently used bytes.
+    pub fn used_bytes(&self) -> u64 {
+        self.quota
+            .as_ref()
+            .map(|quota| quota.permits_to_bytes(quota.used_permits()))
+            .unwrap_or(0)
+    }
+
+    /// Returns available bytes.
+    pub fn available_bytes(&self) -> u64 {
+        self.quota
+            .as_ref()
+            .map(|quota| quota.permits_to_bytes(quota.available_permits_clamped()))
+            .unwrap_or(0)
+    }
+
+    /// Acquires memory, waiting if necessary until enough is available.
+    ///
+    /// # Errors
+    /// - Returns error if requested bytes exceed the total limit
+    /// - Returns error if the semaphore is unexpectedly closed
+    pub async fn acquire(&self, bytes: u64) -> Result<MemoryGuard<M>> {
+        match &self.quota {
+            None => Ok(MemoryGuard::unlimited()),
+            Some(quota) => {
+                let permits = quota.bytes_to_permits(bytes);
+
+                ensure!(
+                    permits <= quota.limit_permits,
+                    MemoryLimitExceededSnafu {
+                        requested_bytes: bytes,
+                        limit_bytes: self.limit_bytes()
+                    }
+                );
+
+                let permit = quota
+                    .semaphore
+                    .clone()
+                    .acquire_many_owned(permits)
+                    .await
+                    .map_err(|_| MemorySemaphoreClosedSnafu.build())?;
+                quota.update_in_use_metric();
+                Ok(MemoryGuard::limited(permit, quota.clone()))
+            }
+        }
+    }
+
+    /// Tries to acquire memory. Returns Some(guard) on success, None if insufficient.
+    pub fn try_acquire(&self, bytes: u64) -> Option<MemoryGuard<M>> {
+        match &self.quota {
+            None => Some(MemoryGuard::unlimited()),
+            Some(quota) => {
+                let permits = quota.bytes_to_permits(bytes);
+
+                match quota.semaphore.clone().try_acquire_many_owned(permits) {
+                    Ok(permit) => {
+                        quota.update_in_use_metric();
+                        Some(MemoryGuard::limited(permit, quota.clone()))
+                    }
+                    Err(TryAcquireError::NoPermits) | Err(TryAcquireError::Closed) => {
+                        quota.metrics.inc_rejected("try_acquire");
+                        None
+                    }
+                }
+            }
+        }
+    }
+
+    /// Acquires memory based on the given policy.
+    ///
+    /// - For `OnExhaustedPolicy::Wait`: Waits up to the timeout duration for memory to become available
+    /// - For `OnExhaustedPolicy::Fail`: Returns immediately if memory is not available
+    ///
+    /// # Errors
+    /// - `MemoryLimitExceeded`: Requested bytes exceed the total limit (both policies), or memory is currently exhausted (Fail policy only)
+    /// - `MemoryAcquireTimeout`: Timeout elapsed while waiting for memory (Wait policy only)
+    /// - `MemorySemaphoreClosed`: The internal semaphore is unexpectedly closed (rare, indicates system issue)
+    pub async fn acquire_with_policy(
+        &self,
+        bytes: u64,
+        policy: OnExhaustedPolicy,
+    ) -> Result<MemoryGuard<M>> {
+        match policy {
+            OnExhaustedPolicy::Wait { timeout } => {
+                match tokio::time::timeout(timeout, self.acquire(bytes)).await {
+                    Ok(Ok(guard)) => Ok(guard),
+                    Ok(Err(e)) => Err(e),
+                    Err(_elapsed) => {
+                        // Timeout elapsed while waiting
+                        MemoryAcquireTimeoutSnafu {
+                            requested_bytes: bytes,
+                            waited: timeout,
+                        }
+                        .fail()
+                    }
+                }
+            }
+            OnExhaustedPolicy::Fail => self.try_acquire(bytes).ok_or_else(|| {
+                MemoryLimitExceededSnafu {
+                    requested_bytes: bytes,
+                    limit_bytes: self.limit_bytes(),
+                }
+                .build()
+            }),
+        }
+    }
+}
+
+impl<M: MemoryMetrics> MemoryQuota<M> {
+    pub(crate) fn bytes_to_permits(&self, bytes: u64) -> u32 {
+        self.granularity.bytes_to_permits(bytes)
+    }
+
+    pub(crate) fn permits_to_bytes(&self, permits: u32) -> u64 {
+        self.granularity.permits_to_bytes(permits)
+    }
+
+    pub(crate) fn used_permits(&self) -> u32 {
+        self.limit_permits
+            .saturating_sub(self.available_permits_clamped())
+    }
+
+    pub(crate) fn available_permits_clamped(&self) -> u32 {
+        self.semaphore
+            .available_permits()
+            .min(self.limit_permits as usize) as u32
+    }
+
+    pub(crate) fn update_in_use_metric(&self) {
+        let bytes = self.permits_to_bytes(self.used_permits());
+        self.metrics.set_in_use(bytes as i64);
+    }
+}

src/common/memory-manager/src/policy.rs

@@ -0,0 +1,83 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::time::Duration;
+
+use humantime::{format_duration, parse_duration};
+use serde::{Deserialize, Serialize};
+
+/// Default wait timeout for memory acquisition.
+pub const DEFAULT_MEMORY_WAIT_TIMEOUT: Duration = Duration::from_secs(10);
+
+/// Defines how to react when memory cannot be acquired immediately.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum OnExhaustedPolicy {
+    /// Wait until enough memory is released, bounded by timeout.
+    Wait { timeout: Duration },
+
+    /// Fail immediately if memory is not available.
+    Fail,
+}
+
+impl Default for OnExhaustedPolicy {
+    fn default() -> Self {
+        OnExhaustedPolicy::Wait {
+            timeout: DEFAULT_MEMORY_WAIT_TIMEOUT,
+        }
+    }
+}
+
+impl Serialize for OnExhaustedPolicy {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        let text = match self {
+            OnExhaustedPolicy::Fail => "fail".to_string(),
+            OnExhaustedPolicy::Wait { timeout } if *timeout == DEFAULT_MEMORY_WAIT_TIMEOUT => {
+                "wait".to_string()
+            }
+            OnExhaustedPolicy::Wait { timeout } => format!("wait({})", format_duration(*timeout)),
+        };
+        serializer.serialize_str(&text)
+    }
+}
+
+impl<'de> Deserialize<'de> for OnExhaustedPolicy {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let raw = String::deserialize(deserializer)?;
+        let lower = raw.to_ascii_lowercase();
+
+        // Accept both "skip" (legacy) and "fail".
+        if lower == "skip" || lower == "fail" {
+            return Ok(OnExhaustedPolicy::Fail);
+        }
+        if lower == "wait" {
+            return Ok(OnExhaustedPolicy::default());
+        }
+        if lower.starts_with("wait(") && lower.ends_with(')') {
+            let inner = &raw[5..raw.len() - 1];
+            let timeout = parse_duration(inner).map_err(serde::de::Error::custom)?;
+            return Ok(OnExhaustedPolicy::Wait { timeout });
+        }
+
+        Err(serde::de::Error::custom(format!(
+            "invalid memory policy: {}, expected wait, wait(<duration>), fail",
+            raw
+        )))
+    }
+}

src/common/memory-manager/src/tests.rs

@@ -0,0 +1,250 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use tokio::time::{Duration, sleep};
+
+use crate::{MemoryManager, NoOpMetrics, PermitGranularity};
+
+// Helper constant for tests - use default Megabyte granularity
+const PERMIT_GRANULARITY_BYTES: u64 = PermitGranularity::Megabyte.bytes();
+
+#[test]
+fn test_try_acquire_unlimited() {
+    let manager = MemoryManager::new(0, NoOpMetrics);
+    let guard = manager.try_acquire(10 * PERMIT_GRANULARITY_BYTES).unwrap();
+    assert_eq!(manager.limit_bytes(), 0);
+    assert_eq!(guard.granted_bytes(), 0);
+}
+
+#[test]
+fn test_try_acquire_limited_success_and_release() {
+    let bytes = 2 * PERMIT_GRANULARITY_BYTES;
+    let manager = MemoryManager::new(bytes, NoOpMetrics);
+    {
+        let guard = manager.try_acquire(PERMIT_GRANULARITY_BYTES).unwrap();
+        assert_eq!(guard.granted_bytes(), PERMIT_GRANULARITY_BYTES);
+        assert_eq!(manager.used_bytes(), PERMIT_GRANULARITY_BYTES);
+        drop(guard);
+    }
+    assert_eq!(manager.used_bytes(), 0);
+}
+
+#[test]
+fn test_try_acquire_exceeds_limit() {
+    let limit = PERMIT_GRANULARITY_BYTES;
+    let manager = MemoryManager::new(limit, NoOpMetrics);
+    let result = manager.try_acquire(limit + PERMIT_GRANULARITY_BYTES);
+    assert!(result.is_none());
+}
+
+#[tokio::test(flavor = "current_thread")]
+async fn test_acquire_blocks_and_unblocks() {
+    let bytes = 2 * PERMIT_GRANULARITY_BYTES;
+    let manager = MemoryManager::new(bytes, NoOpMetrics);
+    let guard = manager.try_acquire(bytes).unwrap();
+
+    // Spawn a task that will block on acquire()
+    let waiter = {
+        let manager = manager.clone();
+        tokio::spawn(async move {
+            // This will block until memory is available
+            let _guard = manager.acquire(bytes).await.unwrap();
+        })
+    };
+
+    sleep(Duration::from_millis(10)).await;
+    // Release memory - this should unblock the waiter
+    drop(guard);
+
+    // Waiter should complete now
+    waiter.await.unwrap();
+}
+
+#[test]
+fn test_request_additional_success() {
+    let limit = 10 * PERMIT_GRANULARITY_BYTES; // 10MB limit
+    let manager = MemoryManager::new(limit, NoOpMetrics);
+
+    // Acquire base quota (5MB)
+    let base = 5 * PERMIT_GRANULARITY_BYTES;
+    let mut guard = manager.try_acquire(base).unwrap();
+    assert_eq!(guard.granted_bytes(), base);
+    assert_eq!(manager.used_bytes(), base);
+
+    // Request additional memory (3MB) - should succeed and merge
+    assert!(guard.request_additional(3 * PERMIT_GRANULARITY_BYTES));
+    assert_eq!(guard.granted_bytes(), 8 * PERMIT_GRANULARITY_BYTES);
+    assert_eq!(manager.used_bytes(), 8 * PERMIT_GRANULARITY_BYTES);
+}
+
+#[test]
+fn test_request_additional_exceeds_limit() {
+    let limit = 10 * PERMIT_GRANULARITY_BYTES; // 10MB limit
+    let manager = MemoryManager::new(limit, NoOpMetrics);
+
+    // Acquire base quota (5MB)
+    let base = 5 * PERMIT_GRANULARITY_BYTES;
+    let mut guard = manager.try_acquire(base).unwrap();
+
+    // Request additional memory (3MB) - should succeed
+    assert!(guard.request_additional(3 * PERMIT_GRANULARITY_BYTES));
+    assert_eq!(manager.used_bytes(), 8 * PERMIT_GRANULARITY_BYTES);
+
+    // Request more (3MB) - should fail (would exceed 10MB limit)
+    let result = guard.request_additional(3 * PERMIT_GRANULARITY_BYTES);
+    assert!(!result);
+
+    // Still at 8MB
+    assert_eq!(manager.used_bytes(), 8 * PERMIT_GRANULARITY_BYTES);
+    assert_eq!(guard.granted_bytes(), 8 * PERMIT_GRANULARITY_BYTES);
+}
+
+#[test]
+fn test_request_additional_auto_release_on_guard_drop() {
+    let limit = 10 * PERMIT_GRANULARITY_BYTES;
+    let manager = MemoryManager::new(limit, NoOpMetrics);
+
+    {
+        let mut guard = manager.try_acquire(5 * PERMIT_GRANULARITY_BYTES).unwrap();
+
+        // Request additional - memory is merged into guard
+        assert!(guard.request_additional(3 * PERMIT_GRANULARITY_BYTES));
+        assert_eq!(manager.used_bytes(), 8 * PERMIT_GRANULARITY_BYTES);
+
+        // When guard drops, all memory (base + additional) is released together
+    }
+
+    // After scope, all memory should be released
+    assert_eq!(manager.used_bytes(), 0);
+}
+
+#[test]
+fn test_request_additional_unlimited() {
+    let manager = MemoryManager::new(0, NoOpMetrics); // Unlimited
+    let mut guard = manager.try_acquire(5 * PERMIT_GRANULARITY_BYTES).unwrap();
+
+    // Should always succeed with unlimited manager
+    assert!(guard.request_additional(100 * PERMIT_GRANULARITY_BYTES));
+    assert_eq!(guard.granted_bytes(), 0);
+    assert_eq!(manager.used_bytes(), 0);
+}
+
+#[test]
+fn test_request_additional_zero_bytes() {
+    let limit = 10 * PERMIT_GRANULARITY_BYTES;
+    let manager = MemoryManager::new(limit, NoOpMetrics);
+
+    let mut guard = manager.try_acquire(5 * PERMIT_GRANULARITY_BYTES).unwrap();
+
+    // Request 0 bytes should succeed without affecting anything
+    assert!(guard.request_additional(0));
+    assert_eq!(guard.granted_bytes(), 5 * PERMIT_GRANULARITY_BYTES);
+    assert_eq!(manager.used_bytes(), 5 * PERMIT_GRANULARITY_BYTES);
+}
+
+#[test]
+fn test_early_release_partial_success() {
+    let limit = 10 * PERMIT_GRANULARITY_BYTES;
+    let manager = MemoryManager::new(limit, NoOpMetrics);
+
+    let mut guard = manager.try_acquire(8 * PERMIT_GRANULARITY_BYTES).unwrap();
+    assert_eq!(manager.used_bytes(), 8 * PERMIT_GRANULARITY_BYTES);
+
+    // Release half
+    assert!(guard.early_release_partial(4 * PERMIT_GRANULARITY_BYTES));
+    assert_eq!(guard.granted_bytes(), 4 * PERMIT_GRANULARITY_BYTES);
+    assert_eq!(manager.used_bytes(), 4 * PERMIT_GRANULARITY_BYTES);
+
+    // Released memory should be available to others
+    let _guard2 = manager.try_acquire(4 * PERMIT_GRANULARITY_BYTES).unwrap();
+    assert_eq!(manager.used_bytes(), 8 * PERMIT_GRANULARITY_BYTES);
+}
+
+#[test]
+fn test_early_release_partial_exceeds_granted() {
+    let manager = MemoryManager::new(10 * PERMIT_GRANULARITY_BYTES, NoOpMetrics);
+    let mut guard = manager.try_acquire(5 * PERMIT_GRANULARITY_BYTES).unwrap();
+
+    // Try to release more than granted - should fail
+    assert!(!guard.early_release_partial(10 * PERMIT_GRANULARITY_BYTES));
+    assert_eq!(guard.granted_bytes(), 5 * PERMIT_GRANULARITY_BYTES);
+    assert_eq!(manager.used_bytes(), 5 * PERMIT_GRANULARITY_BYTES);
+}
+
+#[test]
+fn test_early_release_partial_unlimited() {
+    let manager = MemoryManager::new(0, NoOpMetrics);
+    let mut guard = manager.try_acquire(100 * PERMIT_GRANULARITY_BYTES).unwrap();
+
+    // Unlimited guard - release should succeed (no-op)
+    assert!(guard.early_release_partial(50 * PERMIT_GRANULARITY_BYTES));
+    assert_eq!(guard.granted_bytes(), 0);
+}
+
+#[test]
+fn test_request_and_early_release_symmetry() {
+    let limit = 20 * PERMIT_GRANULARITY_BYTES;
+    let manager = MemoryManager::new(limit, NoOpMetrics);
+
+    let mut guard = manager.try_acquire(5 * PERMIT_GRANULARITY_BYTES).unwrap();
+
+    // Request additional
+    assert!(guard.request_additional(5 * PERMIT_GRANULARITY_BYTES));
+    assert_eq!(guard.granted_bytes(), 10 * PERMIT_GRANULARITY_BYTES);
+    assert_eq!(manager.used_bytes(), 10 * PERMIT_GRANULARITY_BYTES);
+
+    // Early release some
+    assert!(guard.early_release_partial(3 * PERMIT_GRANULARITY_BYTES));
+    assert_eq!(guard.granted_bytes(), 7 * PERMIT_GRANULARITY_BYTES);
+    assert_eq!(manager.used_bytes(), 7 * PERMIT_GRANULARITY_BYTES);
+
+    // Request again
+    assert!(guard.request_additional(2 * PERMIT_GRANULARITY_BYTES));
+    assert_eq!(guard.granted_bytes(), 9 * PERMIT_GRANULARITY_BYTES);
+    assert_eq!(manager.used_bytes(), 9 * PERMIT_GRANULARITY_BYTES);
+
+    // Early release again
+    assert!(guard.early_release_partial(4 * PERMIT_GRANULARITY_BYTES));
+    assert_eq!(guard.granted_bytes(), 5 * PERMIT_GRANULARITY_BYTES);
+    assert_eq!(manager.used_bytes(), 5 * PERMIT_GRANULARITY_BYTES);
+
+    drop(guard);
+    assert_eq!(manager.used_bytes(), 0);
+}
+
+#[test]
+fn test_small_allocation_rounds_up() {
+    // Test that allocations smaller than PERMIT_GRANULARITY_BYTES
+    // round up to 1 permit and can use request_additional()
+    let limit = 10 * PERMIT_GRANULARITY_BYTES;
+    let manager = MemoryManager::new(limit, NoOpMetrics);
+
+    let mut guard = manager.try_acquire(512 * 1024).unwrap(); // 512KB
+    assert_eq!(guard.granted_bytes(), PERMIT_GRANULARITY_BYTES); // Rounds up to 1MB
+    assert!(guard.request_additional(2 * PERMIT_GRANULARITY_BYTES)); // Can request more
+    assert_eq!(guard.granted_bytes(), 3 * PERMIT_GRANULARITY_BYTES);
+}
+
+#[test]
+fn test_acquire_zero_bytes_lazy_allocation() {
+    // Test that acquire(0) returns 0 permits but can request_additional() later
+    let manager = MemoryManager::new(10 * PERMIT_GRANULARITY_BYTES, NoOpMetrics);
+
+    let mut guard = manager.try_acquire(0).unwrap();
+    assert_eq!(guard.granted_bytes(), 0); // No permits consumed
+    assert_eq!(manager.used_bytes(), 0);
+
+    assert!(guard.request_additional(3 * PERMIT_GRANULARITY_BYTES)); // Lazy allocation
+    assert_eq!(guard.granted_bytes(), 3 * PERMIT_GRANULARITY_BYTES);
+}

src/common/meta/src/cluster.rs

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::fmt::{Display, Formatter};
 use std::hash::{DefaultHasher, Hash, Hasher};
 use std::str::FromStr;
 
@@ -60,7 +61,7 @@ pub trait ClusterInfo {
 }
 
 /// The key of [NodeInfo] in the storage. The format is `__meta_cluster_node_info-0-{role}-{node_id}`.
-#[derive(Debug, Clone, Copy, Eq, Hash, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, Copy, Eq, Hash, PartialEq, Serialize, Deserialize, PartialOrd, Ord)]
 pub struct NodeInfoKey {
     /// The role of the node. It can be `[Role::Datanode]` or `[Role::Frontend]`.
     pub role: Role,
@@ -135,7 +136,7 @@ pub struct NodeInfo {
     pub hostname: String,
 }
 
-#[derive(Debug, Clone, Copy, Eq, Hash, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, Copy, Eq, Hash, PartialEq, Serialize, Deserialize, PartialOrd, Ord)]
 pub enum Role {
     Datanode,
     Frontend,
@@ -241,6 +242,12 @@ impl From<&NodeInfoKey> for Vec<u8> {
     }
 }
 
+impl Display for NodeInfoKey {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{:?}-{}", self.role, self.node_id)
+    }
+}
+
 impl FromStr for NodeInfo {
     type Err = Error;
 

src/common/meta/src/ddl.rs

@@ -31,6 +31,7 @@ use crate::region_registry::LeaderRegionRegistryRef;
 pub mod alter_database;
 pub mod alter_logical_tables;
 pub mod alter_table;
+pub mod comment_on;
 pub mod create_database;
 pub mod create_flow;
 pub mod create_logical_tables;

src/common/meta/src/ddl/alter_table/executor.rs

@@ -301,8 +301,8 @@ fn build_new_table_info(
         | AlterKind::UnsetTableOptions { .. }
         | AlterKind::SetIndexes { .. }
         | AlterKind::UnsetIndexes { .. }
-        | AlterKind::DropDefaults { .. } => {}
-        AlterKind::SetDefaults { .. } => {}
+        | AlterKind::DropDefaults { .. }
+        | AlterKind::SetDefaults { .. } => {}
     }
 
     info!(

src/common/meta/src/ddl/comment_on.rs

@@ -0,0 +1,509 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use async_trait::async_trait;
+use chrono::Utc;
+use common_catalog::format_full_table_name;
+use common_procedure::error::{FromJsonSnafu, Result as ProcedureResult, ToJsonSnafu};
+use common_procedure::{Context as ProcedureContext, LockKey, Procedure, Status};
+use common_telemetry::tracing::info;
+use datatypes::schema::COMMENT_KEY as COLUMN_COMMENT_KEY;
+use serde::{Deserialize, Serialize};
+use snafu::{OptionExt, ResultExt, ensure};
+use store_api::storage::TableId;
+use strum::AsRefStr;
+use table::metadata::RawTableInfo;
+use table::requests::COMMENT_KEY as TABLE_COMMENT_KEY;
+use table::table_name::TableName;
+
+use crate::cache_invalidator::Context;
+use crate::ddl::DdlContext;
+use crate::ddl::utils::map_to_procedure_error;
+use crate::error::{ColumnNotFoundSnafu, FlowNotFoundSnafu, Result, TableNotFoundSnafu};
+use crate::instruction::CacheIdent;
+use crate::key::flow::flow_info::{FlowInfoKey, FlowInfoValue};
+use crate::key::table_info::{TableInfoKey, TableInfoValue};
+use crate::key::table_name::TableNameKey;
+use crate::key::{DeserializedValueWithBytes, FlowId, MetadataKey, MetadataValue};
+use crate::lock_key::{CatalogLock, FlowNameLock, SchemaLock, TableNameLock};
+use crate::rpc::ddl::{CommentObjectType, CommentOnTask};
+use crate::rpc::store::PutRequest;
+
+pub struct CommentOnProcedure {
+    pub context: DdlContext,
+    pub data: CommentOnData,
+}
+
+impl CommentOnProcedure {
+    pub const TYPE_NAME: &'static str = "metasrv-procedure::CommentOn";
+
+    pub fn new(task: CommentOnTask, context: DdlContext) -> Self {
+        Self {
+            context,
+            data: CommentOnData::new(task),
+        }
+    }
+
+    pub fn from_json(json: &str, context: DdlContext) -> ProcedureResult<Self> {
+        let data = serde_json::from_str(json).context(FromJsonSnafu)?;
+
+        Ok(Self { context, data })
+    }
+
+    pub async fn on_prepare(&mut self) -> Result<Status> {
+        match self.data.object_type {
+            CommentObjectType::Table | CommentObjectType::Column => {
+                self.prepare_table_or_column().await?;
+            }
+            CommentObjectType::Flow => {
+                self.prepare_flow().await?;
+            }
+        }
+
+        // Fast path: if comment is unchanged, skip update
+        if self.data.is_unchanged {
+            let object_desc = match self.data.object_type {
+                CommentObjectType::Table => format!(
+                    "table {}",
+                    format_full_table_name(
+                        &self.data.catalog_name,
+                        &self.data.schema_name,
+                        &self.data.object_name,
+                    )
+                ),
+                CommentObjectType::Column => format!(
+                    "column {}.{}",
+                    format_full_table_name(
+                        &self.data.catalog_name,
+                        &self.data.schema_name,
+                        &self.data.object_name,
+                    ),
+                    self.data.column_name.as_ref().unwrap()
+                ),
+                CommentObjectType::Flow => {
+                    format!("flow {}.{}", self.data.catalog_name, self.data.object_name)
+                }
+            };
+            info!("Comment unchanged for {}, skipping update", object_desc);
+            return Ok(Status::done());
+        }
+
+        self.data.state = CommentOnState::UpdateMetadata;
+        Ok(Status::executing(true))
+    }
+
+    async fn prepare_table_or_column(&mut self) -> Result<()> {
+        let table_name_key = TableNameKey::new(
+            &self.data.catalog_name,
+            &self.data.schema_name,
+            &self.data.object_name,
+        );
+
+        let table_id = self
+            .context
+            .table_metadata_manager
+            .table_name_manager()
+            .get(table_name_key)
+            .await?
+            .with_context(|| TableNotFoundSnafu {
+                table_name: format_full_table_name(
+                    &self.data.catalog_name,
+                    &self.data.schema_name,
+                    &self.data.object_name,
+                ),
+            })?
+            .table_id();
+
+        let table_info = self
+            .context
+            .table_metadata_manager
+            .table_info_manager()
+            .get(table_id)
+            .await?
+            .with_context(|| TableNotFoundSnafu {
+                table_name: format_full_table_name(
+                    &self.data.catalog_name,
+                    &self.data.schema_name,
+                    &self.data.object_name,
+                ),
+            })?;
+
+        // For column comments, validate the column exists
+        if self.data.object_type == CommentObjectType::Column {
+            let column_name = self.data.column_name.as_ref().unwrap();
+            let column_exists = table_info
+                .table_info
+                .meta
+                .schema
+                .column_schemas
+                .iter()
+                .any(|col| &col.name == column_name);
+
+            ensure!(
+                column_exists,
+                ColumnNotFoundSnafu {
+                    column_name,
+                    column_id: 0u32, // column_id is not known here
+                }
+            );
+        }
+
+        self.data.table_id = Some(table_id);
+
+        // Check if comment is unchanged for early exit optimization
+        match self.data.object_type {
+            CommentObjectType::Table => {
+                let current_comment = &table_info.table_info.desc;
+                if &self.data.comment == current_comment {
+                    self.data.is_unchanged = true;
+                }
+            }
+            CommentObjectType::Column => {
+                let column_name = self.data.column_name.as_ref().unwrap();
+                let column_schema = table_info
+                    .table_info
+                    .meta
+                    .schema
+                    .column_schemas
+                    .iter()
+                    .find(|col| &col.name == column_name)
+                    .unwrap(); // Safe: validated above
+
+                let current_comment = column_schema.metadata().get(COLUMN_COMMENT_KEY);
+                if self.data.comment.as_deref() == current_comment.map(String::as_str) {
+                    self.data.is_unchanged = true;
+                }
+            }
+            CommentObjectType::Flow => {
+                // this branch is handled in `prepare_flow`
+            }
+        }
+
+        self.data.table_info = Some(table_info);
+
+        Ok(())
+    }
+
+    async fn prepare_flow(&mut self) -> Result<()> {
+        let flow_name_value = self
+            .context
+            .flow_metadata_manager
+            .flow_name_manager()
+            .get(&self.data.catalog_name, &self.data.object_name)
+            .await?
+            .with_context(|| FlowNotFoundSnafu {
+                flow_name: &self.data.object_name,
+            })?;
+
+        let flow_id = flow_name_value.flow_id();
+        let flow_info = self
+            .context
+            .flow_metadata_manager
+            .flow_info_manager()
+            .get_raw(flow_id)
+            .await?
+            .with_context(|| FlowNotFoundSnafu {
+                flow_name: &self.data.object_name,
+            })?;
+
+        self.data.flow_id = Some(flow_id);
+
+        // Check if comment is unchanged for early exit optimization
+        let current_comment = &flow_info.get_inner_ref().comment;
+        let new_comment = self.data.comment.as_deref().unwrap_or("");
+        if new_comment == current_comment.as_str() {
+            self.data.is_unchanged = true;
+        }
+
+        self.data.flow_info = Some(flow_info);
+
+        Ok(())
+    }
+
+    pub async fn on_update_metadata(&mut self) -> Result<Status> {
+        match self.data.object_type {
+            CommentObjectType::Table => {
+                self.update_table_comment().await?;
+            }
+            CommentObjectType::Column => {
+                self.update_column_comment().await?;
+            }
+            CommentObjectType::Flow => {
+                self.update_flow_comment().await?;
+            }
+        }
+
+        self.data.state = CommentOnState::InvalidateCache;
+        Ok(Status::executing(true))
+    }
+
+    async fn update_table_comment(&mut self) -> Result<()> {
+        let table_info_value = self.data.table_info.as_ref().unwrap();
+        let mut new_table_info = table_info_value.table_info.clone();
+
+        new_table_info.desc = self.data.comment.clone();
+
+        // Sync comment to table options
+        sync_table_comment_option(
+            &mut new_table_info.meta.options,
+            new_table_info.desc.as_deref(),
+        );
+
+        self.update_table_info(table_info_value, new_table_info)
+            .await?;
+
+        info!(
+            "Updated comment for table {}.{}.{}",
+            self.data.catalog_name, self.data.schema_name, self.data.object_name
+        );
+
+        Ok(())
+    }
+
+    async fn update_column_comment(&mut self) -> Result<()> {
+        let table_info_value = self.data.table_info.as_ref().unwrap();
+        let mut new_table_info = table_info_value.table_info.clone();
+
+        let column_name = self.data.column_name.as_ref().unwrap();
+        let column_schema = new_table_info
+            .meta
+            .schema
+            .column_schemas
+            .iter_mut()
+            .find(|col| &col.name == column_name)
+            .unwrap(); // Safe: validated in prepare
+
+        update_column_comment_metadata(column_schema, self.data.comment.clone());
+
+        self.update_table_info(table_info_value, new_table_info)
+            .await?;
+
+        info!(
+            "Updated comment for column {}.{}.{}.{}",
+            self.data.catalog_name, self.data.schema_name, self.data.object_name, column_name
+        );
+
+        Ok(())
+    }
+
+    async fn update_flow_comment(&mut self) -> Result<()> {
+        let flow_id = self.data.flow_id.unwrap();
+        let flow_info_value = self.data.flow_info.as_ref().unwrap();
+
+        let mut new_flow_info = flow_info_value.get_inner_ref().clone();
+        new_flow_info.comment = self.data.comment.clone().unwrap_or_default();
+        new_flow_info.updated_time = Utc::now();
+
+        let raw_value = new_flow_info.try_as_raw_value()?;
+
+        self.context
+            .table_metadata_manager
+            .kv_backend()
+            .put(
+                PutRequest::new()
+                    .with_key(FlowInfoKey::new(flow_id).to_bytes())
+                    .with_value(raw_value),
+            )
+            .await?;
+
+        info!(
+            "Updated comment for flow {}.{}",
+            self.data.catalog_name, self.data.object_name
+        );
+
+        Ok(())
+    }
+
+    async fn update_table_info(
+        &self,
+        current_table_info: &DeserializedValueWithBytes<TableInfoValue>,
+        new_table_info: RawTableInfo,
+    ) -> Result<()> {
+        let table_id = current_table_info.table_info.ident.table_id;
+        let new_table_info_value = current_table_info.update(new_table_info);
+        let raw_value = new_table_info_value.try_as_raw_value()?;
+
+        self.context
+            .table_metadata_manager
+            .kv_backend()
+            .put(
+                PutRequest::new()
+                    .with_key(TableInfoKey::new(table_id).to_bytes())
+                    .with_value(raw_value),
+            )
+            .await?;
+
+        Ok(())
+    }
+
+    pub async fn on_invalidate_cache(&mut self) -> Result<Status> {
+        let cache_invalidator = &self.context.cache_invalidator;
+
+        match self.data.object_type {
+            CommentObjectType::Table | CommentObjectType::Column => {
+                let table_id = self.data.table_id.unwrap();
+                let table_name = TableName::new(
+                    self.data.catalog_name.clone(),
+                    self.data.schema_name.clone(),
+                    self.data.object_name.clone(),
+                );
+
+                let cache_ident = vec![
+                    CacheIdent::TableId(table_id),
+                    CacheIdent::TableName(table_name),
+                ];
+
+                cache_invalidator
+                    .invalidate(&Context::default(), &cache_ident)
+                    .await?;
+            }
+            CommentObjectType::Flow => {
+                let flow_id = self.data.flow_id.unwrap();
+                let cache_ident = vec![CacheIdent::FlowId(flow_id)];
+
+                cache_invalidator
+                    .invalidate(&Context::default(), &cache_ident)
+                    .await?;
+            }
+        }
+
+        Ok(Status::done())
+    }
+}
+
+#[async_trait]
+impl Procedure for CommentOnProcedure {
+    fn type_name(&self) -> &str {
+        Self::TYPE_NAME
+    }
+
+    async fn execute(&mut self, _ctx: &ProcedureContext) -> ProcedureResult<Status> {
+        match self.data.state {
+            CommentOnState::Prepare => self.on_prepare().await,
+            CommentOnState::UpdateMetadata => self.on_update_metadata().await,
+            CommentOnState::InvalidateCache => self.on_invalidate_cache().await,
+        }
+        .map_err(map_to_procedure_error)
+    }
+
+    fn dump(&self) -> ProcedureResult<String> {
+        serde_json::to_string(&self.data).context(ToJsonSnafu)
+    }
+
+    fn lock_key(&self) -> LockKey {
+        let catalog = &self.data.catalog_name;
+        let schema = &self.data.schema_name;
+
+        let lock_key = match self.data.object_type {
+            CommentObjectType::Table | CommentObjectType::Column => {
+                vec![
+                    CatalogLock::Read(catalog).into(),
+                    SchemaLock::read(catalog, schema).into(),
+                    TableNameLock::new(catalog, schema, &self.data.object_name).into(),
+                ]
+            }
+            CommentObjectType::Flow => {
+                vec![
+                    CatalogLock::Read(catalog).into(),
+                    FlowNameLock::new(catalog, &self.data.object_name).into(),
+                ]
+            }
+        };
+
+        LockKey::new(lock_key)
+    }
+}
+
+#[derive(Debug, Serialize, Deserialize, AsRefStr)]
+enum CommentOnState {
+    Prepare,
+    UpdateMetadata,
+    InvalidateCache,
+}
+
+/// The data of comment on procedure.
+#[derive(Debug, Serialize, Deserialize)]
+pub struct CommentOnData {
+    state: CommentOnState,
+    catalog_name: String,
+    schema_name: String,
+    object_type: CommentObjectType,
+    object_name: String,
+    /// Column name (only for Column comments)
+    column_name: Option<String>,
+    comment: Option<String>,
+    /// Cached table ID (for Table/Column)
+    #[serde(skip_serializing_if = "Option::is_none")]
+    table_id: Option<TableId>,
+    /// Cached table info (for Table/Column)
+    #[serde(skip)]
+    table_info: Option<DeserializedValueWithBytes<TableInfoValue>>,
+    /// Cached flow ID (for Flow)
+    #[serde(skip_serializing_if = "Option::is_none")]
+    flow_id: Option<FlowId>,
+    /// Cached flow info (for Flow)
+    #[serde(skip)]
+    flow_info: Option<DeserializedValueWithBytes<FlowInfoValue>>,
+    /// Whether the comment is unchanged (optimization for early exit)
+    #[serde(skip)]
+    is_unchanged: bool,
+}
+
+impl CommentOnData {
+    pub fn new(task: CommentOnTask) -> Self {
+        Self {
+            state: CommentOnState::Prepare,
+            catalog_name: task.catalog_name,
+            schema_name: task.schema_name,
+            object_type: task.object_type,
+            object_name: task.object_name,
+            column_name: task.column_name,
+            comment: task.comment,
+            table_id: None,
+            table_info: None,
+            flow_id: None,
+            flow_info: None,
+            is_unchanged: false,
+        }
+    }
+}
+
+fn update_column_comment_metadata(
+    column_schema: &mut datatypes::schema::ColumnSchema,
+    comment: Option<String>,
+) {
+    match comment {
+        Some(value) => {
+            column_schema
+                .mut_metadata()
+                .insert(COLUMN_COMMENT_KEY.to_string(), value);
+        }
+        None => {
+            column_schema.mut_metadata().remove(COLUMN_COMMENT_KEY);
+        }
+    }
+}
+
+fn sync_table_comment_option(options: &mut table::requests::TableOptions, comment: Option<&str>) {
+    match comment {
+        Some(value) => {
+            options
+                .extra_options
+                .insert(TABLE_COMMENT_KEY.to_string(), value.to_string());
+        }
+        None => {
+            options.extra_options.remove(TABLE_COMMENT_KEY);
+        }
+    }
+}

src/common/meta/src/ddl_manager.rs

@@ -27,6 +27,7 @@ use store_api::storage::TableId;
 use crate::ddl::alter_database::AlterDatabaseProcedure;
 use crate::ddl::alter_logical_tables::AlterLogicalTablesProcedure;
 use crate::ddl::alter_table::AlterTableProcedure;
+use crate::ddl::comment_on::CommentOnProcedure;
 use crate::ddl::create_database::CreateDatabaseProcedure;
 use crate::ddl::create_flow::CreateFlowProcedure;
 use crate::ddl::create_logical_tables::CreateLogicalTablesProcedure;
@@ -52,18 +53,18 @@ use crate::rpc::ddl::DdlTask::CreateTrigger;
 #[cfg(feature = "enterprise")]
 use crate::rpc::ddl::DdlTask::DropTrigger;
 use crate::rpc::ddl::DdlTask::{
-    AlterDatabase, AlterLogicalTables, AlterTable, CreateDatabase, CreateFlow, CreateLogicalTables,
-    CreateTable, CreateView, DropDatabase, DropFlow, DropLogicalTables, DropTable, DropView,
-    TruncateTable,
+    AlterDatabase, AlterLogicalTables, AlterTable, CommentOn, CreateDatabase, CreateFlow,
+    CreateLogicalTables, CreateTable, CreateView, DropDatabase, DropFlow, DropLogicalTables,
+    DropTable, DropView, TruncateTable,
 };
 #[cfg(feature = "enterprise")]
 use crate::rpc::ddl::trigger::CreateTriggerTask;
 #[cfg(feature = "enterprise")]
 use crate::rpc::ddl::trigger::DropTriggerTask;
 use crate::rpc::ddl::{
-    AlterDatabaseTask, AlterTableTask, CreateDatabaseTask, CreateFlowTask, CreateTableTask,
-    CreateViewTask, DropDatabaseTask, DropFlowTask, DropTableTask, DropViewTask, QueryContext,
-    SubmitDdlTaskRequest, SubmitDdlTaskResponse, TruncateTableTask,
+    AlterDatabaseTask, AlterTableTask, CommentOnTask, CreateDatabaseTask, CreateFlowTask,
+    CreateTableTask, CreateViewTask, DropDatabaseTask, DropFlowTask, DropTableTask, DropViewTask,
+    QueryContext, SubmitDdlTaskRequest, SubmitDdlTaskResponse, TruncateTableTask,
 };
 use crate::rpc::router::RegionRoute;
 
@@ -192,7 +193,8 @@ impl DdlManager {
             TruncateTableProcedure,
             CreateDatabaseProcedure,
             DropDatabaseProcedure,
-            DropViewProcedure
+            DropViewProcedure,
+            CommentOnProcedure
         );
 
         for (type_name, loader_factory) in loaders {
@@ -408,6 +410,19 @@ impl DdlManager {
         self.submit_procedure(procedure_with_id).await
     }
 
+    /// Submits and executes a comment on task.
+    #[tracing::instrument(skip_all)]
+    pub async fn submit_comment_on_task(
+        &self,
+        comment_on_task: CommentOnTask,
+    ) -> Result<(ProcedureId, Option<Output>)> {
+        let context = self.create_context();
+        let procedure = CommentOnProcedure::new(comment_on_task, context);
+        let procedure_with_id = ProcedureWithId::with_random_id(Box::new(procedure));
+
+        self.submit_procedure(procedure_with_id).await
+    }
+
     async fn submit_procedure(
         &self,
         procedure_with_id: ProcedureWithId,
@@ -476,6 +491,7 @@ impl DdlManager {
                     handle_create_view_task(self, create_view_task).await
                 }
                 DropView(drop_view_task) => handle_drop_view_task(self, drop_view_task).await,
+                CommentOn(comment_on_task) => handle_comment_on_task(self, comment_on_task).await,
                 #[cfg(feature = "enterprise")]
                 CreateTrigger(create_trigger_task) => {
                     handle_create_trigger_task(
@@ -907,6 +923,26 @@ async fn handle_create_view_task(
     })
 }
 
+async fn handle_comment_on_task(
+    ddl_manager: &DdlManager,
+    comment_on_task: CommentOnTask,
+) -> Result<SubmitDdlTaskResponse> {
+    let (id, _) = ddl_manager
+        .submit_comment_on_task(comment_on_task.clone())
+        .await?;
+
+    let procedure_id = id.to_string();
+    info!(
+        "Comment on {}.{}.{} is updated via procedure_id {id:?}",
+        comment_on_task.catalog_name, comment_on_task.schema_name, comment_on_task.object_name
+    );
+
+    Ok(SubmitDdlTaskResponse {
+        key: procedure_id.into(),
+        ..Default::default()
+    })
+}
+
 #[cfg(test)]
 mod tests {
     use std::sync::Arc;

src/common/meta/src/distributed_time_constants.rs

@@ -12,25 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::sync::OnceLock;
 use std::time::Duration;
 
-/// Heartbeat interval time (is the basic unit of various time).
-pub const HEARTBEAT_INTERVAL_MILLIS: u64 = 3000;
-
-/// The frontend will also send heartbeats to Metasrv, sending an empty
-/// heartbeat every HEARTBEAT_INTERVAL_MILLIS * 6 seconds.
-pub const FRONTEND_HEARTBEAT_INTERVAL_MILLIS: u64 = HEARTBEAT_INTERVAL_MILLIS * 6;
-
-/// The lease seconds of a region. It's set by 3 heartbeat intervals
-/// (HEARTBEAT_INTERVAL_MILLIS × 3), plus some extra buffer (1 second).
-pub const REGION_LEASE_SECS: u64 =
-    Duration::from_millis(HEARTBEAT_INTERVAL_MILLIS * 3).as_secs() + 1;
-
-/// When creating table or region failover, a target node needs to be selected.
-/// If the node's lease has expired, the `Selector` will not select it.
-pub const DATANODE_LEASE_SECS: u64 = REGION_LEASE_SECS;
-
-pub const FLOWNODE_LEASE_SECS: u64 = DATANODE_LEASE_SECS;
+pub const BASE_HEARTBEAT_INTERVAL: Duration = Duration::from_secs(3);
 
 /// The lease seconds of metasrv leader.
 pub const META_LEASE_SECS: u64 = 5;
@@ -45,12 +30,10 @@ pub const META_KEEP_ALIVE_INTERVAL_SECS: u64 = META_LEASE_SECS / 2;
 pub const HEARTBEAT_TIMEOUT: Duration = Duration::from_secs(META_KEEP_ALIVE_INTERVAL_SECS + 1);
 
 /// The keep-alive interval of the heartbeat channel.
-pub const HEARTBEAT_CHANNEL_KEEP_ALIVE_INTERVAL_SECS: Duration =
-    Duration::from_secs(META_KEEP_ALIVE_INTERVAL_SECS + 1);
+pub const HEARTBEAT_CHANNEL_KEEP_ALIVE_INTERVAL_SECS: Duration = Duration::from_secs(15);
 
 /// The keep-alive timeout of the heartbeat channel.
-pub const HEARTBEAT_CHANNEL_KEEP_ALIVE_TIMEOUT_SECS: Duration =
-    Duration::from_secs(META_KEEP_ALIVE_INTERVAL_SECS + 1);
+pub const HEARTBEAT_CHANNEL_KEEP_ALIVE_TIMEOUT_SECS: Duration = Duration::from_secs(5);
 
 /// The default mailbox round-trip timeout.
 pub const MAILBOX_RTT_SECS: u64 = 1;
@@ -60,3 +43,60 @@ pub const TOPIC_STATS_REPORT_INTERVAL_SECS: u64 = 15;
 
 /// The retention seconds of topic stats.
 pub const TOPIC_STATS_RETENTION_SECS: u64 = TOPIC_STATS_REPORT_INTERVAL_SECS * 100;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+/// The distributed time constants.
+pub struct DistributedTimeConstants {
+    pub heartbeat_interval: Duration,
+    pub frontend_heartbeat_interval: Duration,
+    pub region_lease: Duration,
+    pub datanode_lease: Duration,
+    pub flownode_lease: Duration,
+}
+
+/// The frontend heartbeat interval is 6 times of the base heartbeat interval.
+pub fn frontend_heartbeat_interval(base_heartbeat_interval: Duration) -> Duration {
+    base_heartbeat_interval * 6
+}
+
+impl DistributedTimeConstants {
+    /// Create a new DistributedTimeConstants from the heartbeat interval.
+    pub fn from_heartbeat_interval(heartbeat_interval: Duration) -> Self {
+        let region_lease = heartbeat_interval * 3 + Duration::from_secs(1);
+        let datanode_lease = region_lease;
+        let flownode_lease = datanode_lease;
+        Self {
+            heartbeat_interval,
+            frontend_heartbeat_interval: frontend_heartbeat_interval(heartbeat_interval),
+            region_lease,
+            datanode_lease,
+            flownode_lease,
+        }
+    }
+}
+
+impl Default for DistributedTimeConstants {
+    fn default() -> Self {
+        Self::from_heartbeat_interval(BASE_HEARTBEAT_INTERVAL)
+    }
+}
+
+static DEFAULT_DISTRIBUTED_TIME_CONSTANTS: OnceLock<DistributedTimeConstants> = OnceLock::new();
+
+/// Get the default distributed time constants.
+pub fn default_distributed_time_constants() -> &'static DistributedTimeConstants {
+    DEFAULT_DISTRIBUTED_TIME_CONSTANTS.get_or_init(Default::default)
+}
+
+/// Initialize the default distributed time constants.
+pub fn init_distributed_time_constants(base_heartbeat_interval: Duration) {
+    let distributed_time_constants =
+        DistributedTimeConstants::from_heartbeat_interval(base_heartbeat_interval);
+    DEFAULT_DISTRIBUTED_TIME_CONSTANTS
+        .set(distributed_time_constants)
+        .expect("Failed to set default distributed time constants");
+    common_telemetry::info!(
+        "Initialized default distributed time constants: {:#?}",
+        distributed_time_constants
+    );
+}

src/common/meta/src/error.rs

@@ -272,13 +272,6 @@ pub enum Error {
         location: Location,
     },
 
-    #[snafu(display("Failed to send message: {err_msg}"))]
-    SendMessage {
-        err_msg: String,
-        #[snafu(implicit)]
-        location: Location,
-    },
-
     #[snafu(display("Failed to serde json"))]
     SerdeJson {
         #[snafu(source)]
@@ -1118,7 +1111,7 @@ impl ErrorExt for Error {
             | DeserializeFlexbuffers { .. }
             | ConvertTimeRanges { .. } => StatusCode::Unexpected,
 
-            SendMessage { .. } | GetKvCache { .. } | CacheNotGet { .. } => StatusCode::Internal,
+            GetKvCache { .. } | CacheNotGet { .. } => StatusCode::Internal,
 
             SchemaAlreadyExists { .. } => StatusCode::DatabaseAlreadyExists,
 

src/common/meta/src/heartbeat/handler.rs

@@ -23,6 +23,7 @@ use crate::heartbeat::mailbox::{IncomingMessage, MailboxRef};
 
 pub mod invalidate_table_cache;
 pub mod parse_mailbox_message;
+pub mod suspend;
 #[cfg(test)]
 mod tests;
 

src/common/meta/src/heartbeat/handler/suspend.rs

@@ -0,0 +1,69 @@
+// Copyright 2023 Greptime Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::sync::Arc;
+use std::sync::atomic::{AtomicBool, Ordering};
+
+use async_trait::async_trait;
+use common_telemetry::{info, warn};
+
+use crate::error::Result;
+use crate::heartbeat::handler::{
+    HandleControl, HeartbeatResponseHandler, HeartbeatResponseHandlerContext,
+};
+use crate::instruction::Instruction;
+
+/// A heartbeat response handler that handles special "suspend" error.
+/// It will simply set or clear (if previously set) the inner suspend atomic state.
+pub struct SuspendHandler {
+    suspend: Arc<AtomicBool>,
+}
+
+impl SuspendHandler {
+    pub fn new(suspend: Arc<AtomicBool>) -> Self {
+        Self { suspend }
+    }
+}
+
+#[async_trait]
+impl HeartbeatResponseHandler for SuspendHandler {
+    fn is_acceptable(&self, context: &HeartbeatResponseHandlerContext) -> bool {
+        matches!(
+            context.incoming_message,
+            Some((_, Instruction::Suspend)) | None
+        )
+    }
+
+    async fn handle(&self, context: &mut HeartbeatResponseHandlerContext) -> Result<HandleControl> {
+        let flip_state = |expect: bool| {
+            self.suspend
+                .compare_exchange(expect, !expect, Ordering::Relaxed, Ordering::Relaxed)
+                .is_ok()
+        };
+
+        if let Some((_, Instruction::Suspend)) = context.incoming_message.take() {
+            if flip_state(false) {
+                warn!("Suspend instruction received from meta, entering suspension state");
+            }
+        } else {
+            // Suspended components are made always tried to get rid of this state, we don't want
+            // an "un-suspend" instruction to resume them running. That can be error-prone.
+            // So if the "suspend" instruction is not found in the heartbeat, just unset the state.
+            if flip_state(true) {
+                info!("clear suspend state");
+            }
+        }
+        Ok(HandleControl::Continue)
+    }
+}

src/common/meta/src/heartbeat/mailbox.rs

@@ -15,8 +15,8 @@
 use std::sync::Arc;
 
 use tokio::sync::mpsc::Sender;
+use tokio::sync::mpsc::error::SendError;
 
-use crate::error::{self, Result};
 use crate::instruction::{Instruction, InstructionReply};
 
 pub type IncomingMessage = (MessageMeta, Instruction);
@@ -51,13 +51,8 @@ impl HeartbeatMailbox {
         Self { sender }
     }
 
-    pub async fn send(&self, message: OutgoingMessage) -> Result<()> {
-        self.sender.send(message).await.map_err(|e| {
-            error::SendMessageSnafu {
-                err_msg: e.to_string(),
-            }
-            .build()
-        })
+    pub async fn send(&self, message: OutgoingMessage) -> Result<(), SendError<OutgoingMessage>> {
+        self.sender.send(message).await
     }
 }
 

src/common/meta/src/instruction.rs

@@ -539,6 +539,8 @@ pub enum Instruction {
     GetFileRefs(GetFileRefs),
     /// Triggers garbage collection for a region.
     GcRegions(GcRegions),
+    /// Temporary suspend serving reads or writes
+    Suspend,
 }
 
 impl Instruction {

src/common/meta/src/key/table_info.rs

@@ -94,7 +94,7 @@ impl TableInfoValue {
         }
     }
 
-    pub(crate) fn update(&self, new_table_info: RawTableInfo) -> Self {
+    pub fn update(&self, new_table_info: RawTableInfo) -> Self {
         Self {
             table_info: new_table_info,
             version: self.version + 1,

src/common/meta/src/kv_backend/rds/postgres.rs

@@ -848,7 +848,7 @@ impl PgStore {
                 .context(CreatePostgresPoolSnafu)?,
         };
 
-        Self::with_pg_pool(pool, None, table_name, max_txn_ops).await
+        Self::with_pg_pool(pool, None, table_name, max_txn_ops, false).await
     }
 
     /// Create [PgStore] impl of [KvBackendRef] from url (backward compatibility).
@@ -862,6 +862,7 @@ impl PgStore {
         schema_name: Option<&str>,
         table_name: &str,
         max_txn_ops: usize,
+        auto_create_schema: bool,
     ) -> Result<KvBackendRef> {
         // Ensure the postgres metadata backend is ready to use.
         let client = match pool.get().await {
@@ -873,9 +874,23 @@ impl PgStore {
                 .fail();
             }
         };
+
+        // Automatically create schema if enabled and schema_name is provided.
+        if auto_create_schema
+            && let Some(schema) = schema_name
+            && !schema.is_empty()
+        {
+            let create_schema_sql = format!("CREATE SCHEMA IF NOT EXISTS \"{}\"", schema);
+            client
+                .execute(&create_schema_sql, &[])
+                .await
+                .with_context(|_| PostgresExecutionSnafu {
+                    sql: create_schema_sql.clone(),
+                })?;
+        }
+
         let template_factory = PgSqlTemplateFactory::new(schema_name, table_name);
         let sql_template_set = template_factory.build();
-        // Do not attempt to create schema implicitly.
         client
             .execute(&sql_template_set.create_table_statement, &[])
             .await
@@ -959,7 +974,7 @@ mod tests {
         let Some(pool) = build_pg15_pool().await else {
             return;
         };
-        let res = PgStore::with_pg_pool(pool, None, "pg15_public_should_fail", 128).await;
+        let res = PgStore::with_pg_pool(pool, None, "pg15_public_should_fail", 128, false).await;
         assert!(
             res.is_err(),
             "creating table in public should fail for test_user"
@@ -1214,4 +1229,249 @@ mod tests {
         let t = PgSqlTemplateFactory::format_table_ident(Some(""), "test_table");
         assert_eq!(t, "\"test_table\"");
     }
+
+    #[tokio::test]
+    async fn test_auto_create_schema_enabled() {
+        common_telemetry::init_default_ut_logging();
+        maybe_skip_postgres_integration_test!();
+        let endpoints = std::env::var("GT_POSTGRES_ENDPOINTS").unwrap();
+        let mut cfg = Config::new();
+        cfg.url = Some(endpoints);
+        let pool = cfg
+            .create_pool(Some(Runtime::Tokio1), NoTls)
+            .context(CreatePostgresPoolSnafu)
+            .unwrap();
+
+        let schema_name = "test_auto_create_enabled";
+        let table_name = "test_table";
+
+        // Drop the schema if it exists to start clean
+        let client = pool.get().await.unwrap();
+        let _ = client
+            .execute(
+                &format!("DROP SCHEMA IF EXISTS \"{}\" CASCADE", schema_name),
+                &[],
+            )
+            .await;
+
+        // Create store with auto_create_schema enabled
+        let _ = PgStore::with_pg_pool(pool.clone(), Some(schema_name), table_name, 128, true)
+            .await
+            .unwrap();
+
+        // Verify schema was created
+        let row = client
+            .query_one(
+                "SELECT schema_name FROM information_schema.schemata WHERE schema_name = $1",
+                &[&schema_name],
+            )
+            .await
+            .unwrap();
+        let created_schema: String = row.get(0);
+        assert_eq!(created_schema, schema_name);
+
+        // Verify table was created in the schema
+        let row = client
+            .query_one(
+                "SELECT table_schema, table_name FROM information_schema.tables WHERE table_schema = $1 AND table_name = $2",
+                &[&schema_name, &table_name],
+            )
+            .await
+            .unwrap();
+        let created_table_schema: String = row.get(0);
+        let created_table_name: String = row.get(1);
+        assert_eq!(created_table_schema, schema_name);
+        assert_eq!(created_table_name, table_name);
+
+        // Cleanup
+        let _ = client
+            .execute(
+                &format!("DROP SCHEMA IF EXISTS \"{}\" CASCADE", schema_name),
+                &[],
+            )
+            .await;
+    }
+
+    #[tokio::test]
+    async fn test_auto_create_schema_disabled() {
+        common_telemetry::init_default_ut_logging();
+        maybe_skip_postgres_integration_test!();
+        let endpoints = std::env::var("GT_POSTGRES_ENDPOINTS").unwrap();
+        let mut cfg = Config::new();
+        cfg.url = Some(endpoints);
+        let pool = cfg
+            .create_pool(Some(Runtime::Tokio1), NoTls)
+            .context(CreatePostgresPoolSnafu)
+            .unwrap();
+
+        let schema_name = "test_auto_create_disabled";
+        let table_name = "test_table";
+
+        // Drop the schema if it exists to start clean
+        let client = pool.get().await.unwrap();
+        let _ = client
+            .execute(
+                &format!("DROP SCHEMA IF EXISTS \"{}\" CASCADE", schema_name),
+                &[],
+            )
+            .await;
+
+        // Try to create store with auto_create_schema disabled (should fail)
+        let result =
+            PgStore::with_pg_pool(pool.clone(), Some(schema_name), table_name, 128, false).await;
+
+        // Verify it failed because schema doesn't exist
+        assert!(
+            result.is_err(),
+            "Expected error when schema doesn't exist and auto_create_schema is disabled"
+        );
+    }
+
+    #[tokio::test]
+    async fn test_auto_create_schema_already_exists() {
+        common_telemetry::init_default_ut_logging();
+        maybe_skip_postgres_integration_test!();
+        let endpoints = std::env::var("GT_POSTGRES_ENDPOINTS").unwrap();
+        let mut cfg = Config::new();
+        cfg.url = Some(endpoints);
+        let pool = cfg
+            .create_pool(Some(Runtime::Tokio1), NoTls)
+            .context(CreatePostgresPoolSnafu)
+            .unwrap();
+
+        let schema_name = "test_auto_create_existing";
+        let table_name = "test_table";
+
+        // Manually create the schema first
+        let client = pool.get().await.unwrap();
+        let _ = client
+            .execute(
+                &format!("DROP SCHEMA IF EXISTS \"{}\" CASCADE", schema_name),
+                &[],
+            )
+            .await;
+        client
+            .execute(&format!("CREATE SCHEMA \"{}\"", schema_name), &[])
+            .await
+            .unwrap();
+
+        // Create store with auto_create_schema enabled (should succeed idempotently)
+        let _ = PgStore::with_pg_pool(pool.clone(), Some(schema_name), table_name, 128, true)
+            .await
+            .unwrap();
+
+        // Verify schema still exists
+        let row = client
+            .query_one(
+                "SELECT schema_name FROM information_schema.schemata WHERE schema_name = $1",
+                &[&schema_name],
+            )
+            .await
+            .unwrap();
+        let created_schema: String = row.get(0);
+        assert_eq!(created_schema, schema_name);
+
+        // Verify table was created in the schema
+        let row = client
+            .query_one(
+                "SELECT table_schema, table_name FROM information_schema.tables WHERE table_schema = $1 AND table_name = $2",
+                &[&schema_name, &table_name],
+            )
+            .await
+            .unwrap();
+        let created_table_schema: String = row.get(0);
+        let created_table_name: String = row.get(1);
+        assert_eq!(created_table_schema, schema_name);
+        assert_eq!(created_table_name, table_name);
+
+        // Cleanup
+        let _ = client
+            .execute(
+                &format!("DROP SCHEMA IF EXISTS \"{}\" CASCADE", schema_name),
+                &[],
+            )
+            .await;
+    }
+
+    #[tokio::test]
+    async fn test_auto_create_schema_no_schema_name() {
+        common_telemetry::init_default_ut_logging();
+        maybe_skip_postgres_integration_test!();
+        let endpoints = std::env::var("GT_POSTGRES_ENDPOINTS").unwrap();
+        let mut cfg = Config::new();
+        cfg.url = Some(endpoints);
+        let pool = cfg
+            .create_pool(Some(Runtime::Tokio1), NoTls)
+            .context(CreatePostgresPoolSnafu)
+            .unwrap();
+
+        let table_name = "test_table_no_schema";
+
+        // Create store with auto_create_schema enabled but no schema name (should succeed)
+        // This should create the table in the default schema (public)
+        let _ = PgStore::with_pg_pool(pool.clone(), None, table_name, 128, true)
+            .await
+            .unwrap();
+
+        // Verify table was created in public schema
+        let client = pool.get().await.unwrap();
+        let row = client
+            .query_one(
+                "SELECT table_schema, table_name FROM information_schema.tables WHERE table_name = $1",
+                &[&table_name],
+            )
+            .await
+            .unwrap();
+        let created_table_schema: String = row.get(0);
+        let created_table_name: String = row.get(1);
+        assert_eq!(created_table_name, table_name);
+        // Verify it's in public schema (or whichever is the default)
+        assert!(created_table_schema == "public" || !created_table_schema.is_empty());
+
+        // Cleanup
+        let _ = client
+            .execute(&format!("DROP TABLE IF EXISTS \"{}\"", table_name), &[])
+            .await;
+    }
+
+    #[tokio::test]
+    async fn test_auto_create_schema_with_empty_schema_name() {
+        common_telemetry::init_default_ut_logging();
+        maybe_skip_postgres_integration_test!();
+        let endpoints = std::env::var("GT_POSTGRES_ENDPOINTS").unwrap();
+        let mut cfg = Config::new();
+        cfg.url = Some(endpoints);
+        let pool = cfg
+            .create_pool(Some(Runtime::Tokio1), NoTls)
+            .context(CreatePostgresPoolSnafu)
+            .unwrap();
+
+        let table_name = "test_table_empty_schema";
+
+        // Create store with auto_create_schema enabled but empty schema name (should succeed)
+        // This should create the table in the default schema (public)
+        let _ = PgStore::with_pg_pool(pool.clone(), Some(""), table_name, 128, true)
+            .await
+            .unwrap();
+
+        // Verify table was created in public schema
+        let client = pool.get().await.unwrap();
+        let row = client
+            .query_one(
+                "SELECT table_schema, table_name FROM information_schema.tables WHERE table_name = $1",
+                &[&table_name],
+            )
+            .await
+            .unwrap();
+        let created_table_schema: String = row.get(0);
+        let created_table_name: String = row.get(1);
+        assert_eq!(created_table_name, table_name);
+        // Verify it's in public schema (or whichever is the default)
+        assert!(created_table_schema == "public" || !created_table_schema.is_empty());
+
+        // Cleanup
+        let _ = client
+            .execute(&format!("DROP TABLE IF EXISTS \"{}\"", table_name), &[])
+            .await;
+    }
 }

src/common/meta/src/rpc/ddl.rs

@@ -23,19 +23,20 @@ use api::v1::alter_database_expr::Kind as PbAlterDatabaseKind;
 use api::v1::meta::ddl_task_request::Task;
 use api::v1::meta::{
     AlterDatabaseTask as PbAlterDatabaseTask, AlterTableTask as PbAlterTableTask,
-    AlterTableTasks as PbAlterTableTasks, CreateDatabaseTask as PbCreateDatabaseTask,
-    CreateFlowTask as PbCreateFlowTask, CreateTableTask as PbCreateTableTask,
-    CreateTableTasks as PbCreateTableTasks, CreateViewTask as PbCreateViewTask,
-    DdlTaskRequest as PbDdlTaskRequest, DdlTaskResponse as PbDdlTaskResponse,
-    DropDatabaseTask as PbDropDatabaseTask, DropFlowTask as PbDropFlowTask,
-    DropTableTask as PbDropTableTask, DropTableTasks as PbDropTableTasks,
-    DropViewTask as PbDropViewTask, Partition, ProcedureId,
+    AlterTableTasks as PbAlterTableTasks, CommentOnTask as PbCommentOnTask,
+    CreateDatabaseTask as PbCreateDatabaseTask, CreateFlowTask as PbCreateFlowTask,
+    CreateTableTask as PbCreateTableTask, CreateTableTasks as PbCreateTableTasks,
+    CreateViewTask as PbCreateViewTask, DdlTaskRequest as PbDdlTaskRequest,
+    DdlTaskResponse as PbDdlTaskResponse, DropDatabaseTask as PbDropDatabaseTask,
+    DropFlowTask as PbDropFlowTask, DropTableTask as PbDropTableTask,
+    DropTableTasks as PbDropTableTasks, DropViewTask as PbDropViewTask, Partition, ProcedureId,
     TruncateTableTask as PbTruncateTableTask,
 };
 use api::v1::{
-    AlterDatabaseExpr, AlterTableExpr, CreateDatabaseExpr, CreateFlowExpr, CreateTableExpr,
-    CreateViewExpr, DropDatabaseExpr, DropFlowExpr, DropTableExpr, DropViewExpr, EvalInterval,
-    ExpireAfter, Option as PbOption, QueryContext as PbQueryContext, TruncateTableExpr,
+    AlterDatabaseExpr, AlterTableExpr, CommentObjectType as PbCommentObjectType, CommentOnExpr,
+    CreateDatabaseExpr, CreateFlowExpr, CreateTableExpr, CreateViewExpr, DropDatabaseExpr,
+    DropFlowExpr, DropTableExpr, DropViewExpr, EvalInterval, ExpireAfter, Option as PbOption,
+    QueryContext as PbQueryContext, TruncateTableExpr,
 };
 use base64::Engine as _;
 use base64::engine::general_purpose;
@@ -78,6 +79,7 @@ pub enum DdlTask {
     DropView(DropViewTask),
     #[cfg(feature = "enterprise")]
     CreateTrigger(trigger::CreateTriggerTask),
+    CommentOn(CommentOnTask),
 }
 
 impl DdlTask {
@@ -200,6 +202,11 @@ impl DdlTask {
             view_info,
         })
     }
+
+    /// Creates a [`DdlTask`] to comment on a table, column, or flow.
+    pub fn new_comment_on(task: CommentOnTask) -> Self {
+        DdlTask::CommentOn(task)
+    }
 }
 
 impl TryFrom<Task> for DdlTask {
@@ -278,6 +285,7 @@ impl TryFrom<Task> for DdlTask {
                     .fail()
                 }
             }
+            Task::CommentOnTask(comment_on) => Ok(DdlTask::CommentOn(comment_on.try_into()?)),
         }
     }
 }
@@ -332,6 +340,7 @@ impl TryFrom<SubmitDdlTaskRequest> for PbDdlTaskRequest {
             DdlTask::CreateTrigger(task) => Task::CreateTriggerTask(task.try_into()?),
             #[cfg(feature = "enterprise")]
             DdlTask::DropTrigger(task) => Task::DropTriggerTask(task.into()),
+            DdlTask::CommentOn(task) => Task::CommentOnTask(task.into()),
         };
 
         Ok(Self {
@@ -1277,6 +1286,119 @@ impl From<DropFlowTask> for PbDropFlowTask {
     }
 }
 
+/// Represents the ID of the object being commented on (Table or Flow).
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+pub enum CommentObjectId {
+    Table(TableId),
+    Flow(FlowId),
+}
+
+/// Comment on table, column, or flow
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+pub struct CommentOnTask {
+    pub catalog_name: String,
+    pub schema_name: String,
+    pub object_type: CommentObjectType,
+    pub object_name: String,
+    /// Column name (only for Column comments)
+    pub column_name: Option<String>,
+    /// Object ID (Table or Flow) for validation and cache invalidation
+    pub object_id: Option<CommentObjectId>,
+    pub comment: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+pub enum CommentObjectType {
+    Table,
+    Column,
+    Flow,
+}
+
+impl CommentOnTask {
+    pub fn table_ref(&self) -> TableReference<'_> {
+        TableReference {
+            catalog: &self.catalog_name,
+            schema: &self.schema_name,
+            table: &self.object_name,
+        }
+    }
+}
+
+// Proto conversions for CommentObjectType
+impl From<CommentObjectType> for PbCommentObjectType {
+    fn from(object_type: CommentObjectType) -> Self {
+        match object_type {
+            CommentObjectType::Table => PbCommentObjectType::Table,
+            CommentObjectType::Column => PbCommentObjectType::Column,
+            CommentObjectType::Flow => PbCommentObjectType::Flow,
+        }
+    }
+}
+
+impl TryFrom<i32> for CommentObjectType {
+    type Error = error::Error;
+
+    fn try_from(value: i32) -> Result<Self> {
+        match value {
+            0 => Ok(CommentObjectType::Table),
+            1 => Ok(CommentObjectType::Column),
+            2 => Ok(CommentObjectType::Flow),
+            _ => error::InvalidProtoMsgSnafu {
+                err_msg: format!(
+                    "Invalid CommentObjectType value: {}. Valid values are: 0 (Table), 1 (Column), 2 (Flow)",
+                    value
+                ),
+            }
+            .fail(),
+        }
+    }
+}
+
+// Proto conversions for CommentOnTask
+impl TryFrom<PbCommentOnTask> for CommentOnTask {
+    type Error = error::Error;
+
+    fn try_from(pb: PbCommentOnTask) -> Result<Self> {
+        let comment_on = pb.comment_on.context(error::InvalidProtoMsgSnafu {
+            err_msg: "expected comment_on",
+        })?;
+
+        Ok(CommentOnTask {
+            catalog_name: comment_on.catalog_name,
+            schema_name: comment_on.schema_name,
+            object_type: comment_on.object_type.try_into()?,
+            object_name: comment_on.object_name,
+            column_name: if comment_on.column_name.is_empty() {
+                None
+            } else {
+                Some(comment_on.column_name)
+            },
+            comment: if comment_on.comment.is_empty() {
+                None
+            } else {
+                Some(comment_on.comment)
+            },
+            object_id: None,
+        })
+    }
+}
+
+impl From<CommentOnTask> for PbCommentOnTask {
+    fn from(task: CommentOnTask) -> Self {
+        let pb_object_type: PbCommentObjectType = task.object_type.into();
+        PbCommentOnTask {
+            comment_on: Some(CommentOnExpr {
+                catalog_name: task.catalog_name,
+                schema_name: task.schema_name,
+                object_type: pb_object_type as i32,
+                object_name: task.object_name,
+                column_name: task.column_name.unwrap_or_default(),
+                comment: task.comment.unwrap_or_default(),
+            }),
+        }
+    }
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 pub struct QueryContext {
     pub(crate) current_catalog: String,

src/common/meta/src/wal_options_allocator/topic_creator.rs

@@ -205,11 +205,14 @@ impl KafkaTopicCreator {
         self.partition_client(topic).await.unwrap()
     }
 }
+
 /// Builds a kafka [Client](rskafka::client::Client).
 pub async fn build_kafka_client(connection: &KafkaConnectionConfig) -> Result<Client> {
     // Builds an kafka controller client for creating topics.
     let mut builder = ClientBuilder::new(connection.broker_endpoints.clone())
-        .backoff_config(DEFAULT_BACKOFF_CONFIG);
+        .backoff_config(DEFAULT_BACKOFF_CONFIG)
+        .connect_timeout(Some(connection.connect_timeout))
+        .timeout(Some(connection.timeout));
     if let Some(sasl) = &connection.sasl {
         builder = builder.sasl_config(sasl.config.clone().into_sasl_config());
     };

src/common/procedure/src/local/runner.rs

@@ -331,8 +331,29 @@ impl Runner {
                         }
 
                         match status {
-                            Status::Executing { .. } => {}
+                            Status::Executing { .. } => {
+                                let prev_state = self.meta.state();
+                                if !matches!(prev_state, ProcedureState::Running) {
+                                    info!(
+                                        "Set Procedure {}-{} state to running, prev_state: {:?}",
+                                        self.procedure.type_name(),
+                                        self.meta.id,
+                                        prev_state
+                                    );
+                                    self.meta.set_state(ProcedureState::Running);
+                                }
+                            }
                             Status::Suspended { subprocedures, .. } => {
+                                let prev_state = self.meta.state();
+                                if !matches!(prev_state, ProcedureState::Running) {
+                                    info!(
+                                        "Set Procedure {}-{} state to running, prev_state: {:?}",
+                                        self.procedure.type_name(),
+                                        self.meta.id,
+                                        prev_state
+                                    );
+                                    self.meta.set_state(ProcedureState::Running);
+                                }
                                 self.on_suspended(subprocedures).await;
                             }
                             Status::Done { output } => {
@@ -393,8 +414,12 @@ impl Runner {
                             return;
                         }
 
+                        if self.procedure.rollback_supported() {
                             self.meta
                                 .set_state(ProcedureState::prepare_rollback(Arc::new(e)));
+                        } else {
+                            self.meta.set_state(ProcedureState::failed(Arc::new(e)));
+                        }
                     }
                 }
             }
@@ -1080,20 +1105,10 @@ mod tests {
         let mut runner = new_runner(meta.clone(), Box::new(fail), procedure_store.clone());
         runner.manager_ctx.start();
 
-        runner.execute_once(&ctx).await;
-        let state = runner.meta.state();
-        assert!(state.is_prepare_rollback(), "{state:?}");
-
         runner.execute_once(&ctx).await;
         let state = runner.meta.state();
         assert!(state.is_failed(), "{state:?}");
-        check_files(
-            &object_store,
-            &procedure_store,
-            ctx.procedure_id,
-            &["0000000000.rollback"],
-        )
-        .await;
+        check_files(&object_store, &procedure_store, ctx.procedure_id, &[]).await;
     }
 
     #[tokio::test]
@@ -1146,6 +1161,8 @@ mod tests {
             async move {
                 if times == 1 {
                     Err(Error::retry_later(MockError::new(StatusCode::Unexpected)))
+                } else if times == 2 {
+                    Ok(Status::executing(false))
                 } else {
                     Ok(Status::done())
                 }
@@ -1172,6 +1189,10 @@ mod tests {
         let state = runner.meta.state();
         assert!(state.is_retrying(), "{state:?}");
 
+        runner.execute_once(&ctx).await;
+        let state = runner.meta.state();
+        assert!(state.is_running(), "{state:?}");
+
         runner.execute_once(&ctx).await;
         let state = runner.meta.state();
         assert!(state.is_done(), "{state:?}");
@@ -1185,6 +1206,86 @@ mod tests {
         .await;
     }
 
+    #[tokio::test(flavor = "multi_thread")]
+    async fn test_execute_on_retry_later_error_with_child() {
+        common_telemetry::init_default_ut_logging();
+        let mut times = 0;
+        let child_id = ProcedureId::random();
+
+        let exec_fn = move |_| {
+            times += 1;
+            async move {
+                debug!("times: {}", times);
+                if times == 1 {
+                    Err(Error::retry_later(MockError::new(StatusCode::Unexpected)))
+                } else if times == 2 {
+                    let exec_fn = |_| {
+                        async { Err(Error::external(MockError::new(StatusCode::Unexpected))) }
+                            .boxed()
+                    };
+                    let fail = ProcedureAdapter {
+                        data: "fail".to_string(),
+                        lock_key: LockKey::single_exclusive("catalog.schema.table.region-0"),
+                        poison_keys: PoisonKeys::default(),
+                        exec_fn,
+                        rollback_fn: None,
+                    };
+
+                    Ok(Status::Suspended {
+                        subprocedures: vec![ProcedureWithId {
+                            id: child_id,
+                            procedure: Box::new(fail),
+                        }],
+                        persist: true,
+                    })
+                } else {
+                    Ok(Status::done())
+                }
+            }
+            .boxed()
+        };
+
+        let retry_later = ProcedureAdapter {
+            data: "retry_later".to_string(),
+            lock_key: LockKey::single_exclusive("catalog.schema.table"),
+            poison_keys: PoisonKeys::default(),
+            exec_fn,
+            rollback_fn: None,
+        };
+
+        let dir = create_temp_dir("retry_later");
+        let meta = retry_later.new_meta(ROOT_ID);
+        let ctx = context_without_provider(meta.id);
+        let object_store = test_util::new_object_store(&dir);
+        let procedure_store = Arc::new(ProcedureStore::from_object_store(object_store.clone()));
+        let mut runner = new_runner(meta.clone(), Box::new(retry_later), procedure_store.clone());
+        runner.manager_ctx.start();
+        debug!("execute_once 1");
+        runner.execute_once(&ctx).await;
+        let state = runner.meta.state();
+        assert!(state.is_retrying(), "{state:?}");
+
+        let moved_meta = meta.clone();
+        tokio::spawn(async move {
+            moved_meta.child_notify.notify_one();
+        });
+        runner.execute_once(&ctx).await;
+        let state = runner.meta.state();
+        assert!(state.is_running(), "{state:?}");
+
+        runner.execute_once(&ctx).await;
+        let state = runner.meta.state();
+        assert!(state.is_done(), "{state:?}");
+        assert!(meta.state().is_done());
+        check_files(
+            &object_store,
+            &procedure_store,
+            ctx.procedure_id,
+            &["0000000000.step", "0000000001.commit"],
+        )
+        .await;
+    }
+
     #[tokio::test]
     async fn test_execute_exceed_max_retry_later() {
         let exec_fn =
@@ -1304,7 +1405,7 @@ mod tests {
     async fn test_child_error() {
         let mut times = 0;
         let child_id = ProcedureId::random();
-
+        common_telemetry::init_default_ut_logging();
         let exec_fn = move |ctx: Context| {
             times += 1;
             async move {
@@ -1529,7 +1630,7 @@ mod tests {
 
         runner.execute_once(&ctx).await;
         let state = runner.meta.state();
-        assert!(state.is_prepare_rollback(), "{state:?}");
+        assert!(state.is_failed(), "{state:?}");
 
         let procedure_id = runner
             .manager_ctx
@@ -1596,11 +1697,6 @@ mod tests {
         let state = runner.meta.state();
         assert!(state.is_running(), "{state:?}");
 
-        runner.execute_once(&ctx).await;
-        let state = runner.meta.state();
-        assert!(state.is_prepare_rollback(), "{state:?}");
-        assert!(meta.state().is_prepare_rollback());
-
         runner.execute_once(&ctx).await;
         let state = runner.meta.state();
         assert!(state.is_failed(), "{state:?}");

src/common/query/src/lib.rs

@@ -46,6 +46,22 @@ pub enum OutputData {
     Stream(SendableRecordBatchStream),
 }
 
+impl OutputData {
+    /// Consume the data to pretty printed string.
+    pub async fn pretty_print(self) -> String {
+        match self {
+            OutputData::AffectedRows(x) => {
+                format!("Affected Rows: {x}")
+            }
+            OutputData::RecordBatches(x) => x.pretty_print().unwrap_or_else(|e| e.to_string()),
+            OutputData::Stream(x) => common_recordbatch::util::collect_batches(x)
+                .await
+                .and_then(|x| x.pretty_print())
+                .unwrap_or_else(|e| e.to_string()),
+        }
+    }
+}
+
 /// OutputMeta stores meta information produced/generated during the execution
 #[derive(Debug, Default)]
 pub struct OutputMeta {

src/common/stat/src/resource.rs

@@ -58,10 +58,14 @@ pub fn get_total_memory_bytes() -> i64 {
     }
 }
 
-/// Get the total CPU cores. The result will be rounded to the nearest integer.
-/// For example, if the total CPU is 1.5 cores(1500 millicores), the result will be 2.
+/// Get the total CPU cores. The result will be rounded up to the next integer (ceiling).
+/// For example, if the total CPU is 1.1 cores (1100 millicores) or 1.5 cores (1500 millicores), the result will be 2.
 pub fn get_total_cpu_cores() -> usize {
-    ((get_total_cpu_millicores() as f64) / 1000.0).round() as usize
+    cpu_cores(get_total_cpu_millicores())
+}
+
+fn cpu_cores(cpu_millicores: i64) -> usize {
+    ((cpu_millicores as f64) / 1_000.0).ceil() as usize
 }
 
 /// Get the total memory in readable size.
@@ -178,6 +182,13 @@ mod tests {
     #[test]
     fn test_get_total_cpu_cores() {
         assert!(get_total_cpu_cores() > 0);
+        assert_eq!(cpu_cores(1), 1);
+        assert_eq!(cpu_cores(100), 1);
+        assert_eq!(cpu_cores(500), 1);
+        assert_eq!(cpu_cores(1000), 1);
+        assert_eq!(cpu_cores(1100), 2);
+        assert_eq!(cpu_cores(1900), 2);
+        assert_eq!(cpu_cores(10_000), 10);
     }
 
     #[test]

src/common/telemetry/src/metric.rs

@@ -71,6 +71,7 @@ pub fn convert_metric_to_write_request(
                         timestamp,
                     }],
                     exemplars: vec![],
+                    histograms: vec![],
                 }),
                 MetricType::GAUGE => timeseries.push(TimeSeries {
                     labels: convert_label(m.get_label(), mf_name, None),
@@ -79,6 +80,7 @@ pub fn convert_metric_to_write_request(
                         timestamp,
                     }],
                     exemplars: vec![],
+                    histograms: vec![],
                 }),
                 MetricType::HISTOGRAM => {
                     let h = m.get_histogram();
@@ -97,6 +99,7 @@ pub fn convert_metric_to_write_request(
                                 timestamp,
                             }],
                             exemplars: vec![],
+                            histograms: vec![],
                         });
                         if upper_bound.is_sign_positive() && upper_bound.is_infinite() {
                             inf_seen = true;
@@ -114,6 +117,7 @@ pub fn convert_metric_to_write_request(
                                 timestamp,
                             }],
                             exemplars: vec![],
+                            histograms: vec![],
                         });
                     }
                     timeseries.push(TimeSeries {
@@ -127,6 +131,7 @@ pub fn convert_metric_to_write_request(
                             timestamp,
                         }],
                         exemplars: vec![],
+                        histograms: vec![],
                     });
                     timeseries.push(TimeSeries {
                         labels: convert_label(
@@ -139,6 +144,7 @@ pub fn convert_metric_to_write_request(
                             timestamp,
                         }],
                         exemplars: vec![],
+                        histograms: vec![],
                     });
                 }
                 MetricType::SUMMARY => {
@@ -155,6 +161,7 @@ pub fn convert_metric_to_write_request(
                                 timestamp,
                             }],
                             exemplars: vec![],
+                            histograms: vec![],
                         });
                     }
                     timeseries.push(TimeSeries {
@@ -168,6 +175,7 @@ pub fn convert_metric_to_write_request(
                             timestamp,
                         }],
                         exemplars: vec![],
+                        histograms: vec![],
                     });
                     timeseries.push(TimeSeries {
                         labels: convert_label(
@@ -180,6 +188,7 @@ pub fn convert_metric_to_write_request(
                             timestamp,
                         }],
                         exemplars: vec![],
+                        histograms: vec![],
                     });
                 }
                 MetricType::UNTYPED => {
@@ -274,7 +283,7 @@ mod test {
 
         assert_eq!(
             format!("{:?}", write_quest.timeseries),
-            r#"[TimeSeries { labels: [Label { name: "__name__", value: "test_counter" }, Label { name: "a", value: "1" }, Label { name: "b", value: "2" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [] }]"#
+            r#"[TimeSeries { labels: [Label { name: "__name__", value: "test_counter" }, Label { name: "a", value: "1" }, Label { name: "b", value: "2" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [], histograms: [] }]"#
         );
 
         let gauge_opts = Opts::new("test_gauge", "test help")
@@ -288,7 +297,7 @@ mod test {
         let write_quest = convert_metric_to_write_request(mf, None, 0);
         assert_eq!(
             format!("{:?}", write_quest.timeseries),
-            r#"[TimeSeries { labels: [Label { name: "__name__", value: "test_gauge" }, Label { name: "a", value: "1" }, Label { name: "b", value: "2" }], samples: [Sample { value: 42.0, timestamp: 0 }], exemplars: [] }]"#
+            r#"[TimeSeries { labels: [Label { name: "__name__", value: "test_gauge" }, Label { name: "a", value: "1" }, Label { name: "b", value: "2" }], samples: [Sample { value: 42.0, timestamp: 0 }], exemplars: [], histograms: [] }]"#
         );
     }
 
@@ -305,20 +314,20 @@ mod test {
             .iter()
             .map(|x| format!("{:?}", x))
             .collect();
-        let ans = r#"TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.005" }], samples: [Sample { value: 0.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.01" }], samples: [Sample { value: 0.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.025" }], samples: [Sample { value: 0.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.05" }], samples: [Sample { value: 0.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.1" }], samples: [Sample { value: 0.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.25" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.5" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "1" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "2.5" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "5" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "10" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "+Inf" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_sum" }, Label { name: "a", value: "1" }], samples: [Sample { value: 0.25, timestamp: 0 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_count" }, Label { name: "a", value: "1" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [] }"#;
+        let ans = r#"TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.005" }], samples: [Sample { value: 0.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.01" }], samples: [Sample { value: 0.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.025" }], samples: [Sample { value: 0.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.05" }], samples: [Sample { value: 0.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.1" }], samples: [Sample { value: 0.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.25" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "0.5" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "1" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "2.5" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "5" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "10" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_bucket" }, Label { name: "a", value: "1" }, Label { name: "le", value: "+Inf" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_sum" }, Label { name: "a", value: "1" }], samples: [Sample { value: 0.25, timestamp: 0 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_count" }, Label { name: "a", value: "1" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [], histograms: [] }"#;
         assert_eq!(write_quest_str.join("\n"), ans);
     }
 
@@ -355,10 +364,10 @@ TimeSeries { labels: [Label { name: "__name__", value: "test_histogram_count" },
             .iter()
             .map(|x| format!("{:?}", x))
             .collect();
-        let ans = r#"TimeSeries { labels: [Label { name: "__name__", value: "test_summary" }, Label { name: "quantile", value: "50" }], samples: [Sample { value: 3.0, timestamp: 20 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_summary" }, Label { name: "quantile", value: "100" }], samples: [Sample { value: 5.0, timestamp: 20 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_summary_sum" }], samples: [Sample { value: 15.0, timestamp: 20 }], exemplars: [] }
-TimeSeries { labels: [Label { name: "__name__", value: "test_summary_count" }], samples: [Sample { value: 5.0, timestamp: 20 }], exemplars: [] }"#;
+        let ans = r#"TimeSeries { labels: [Label { name: "__name__", value: "test_summary" }, Label { name: "quantile", value: "50" }], samples: [Sample { value: 3.0, timestamp: 20 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_summary" }, Label { name: "quantile", value: "100" }], samples: [Sample { value: 5.0, timestamp: 20 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_summary_sum" }], samples: [Sample { value: 15.0, timestamp: 20 }], exemplars: [], histograms: [] }
+TimeSeries { labels: [Label { name: "__name__", value: "test_summary_count" }], samples: [Sample { value: 5.0, timestamp: 20 }], exemplars: [], histograms: [] }"#;
         assert_eq!(write_quest_str.join("\n"), ans);
     }
 
@@ -385,11 +394,11 @@ TimeSeries { labels: [Label { name: "__name__", value: "test_summary_count" }],
         let write_quest2 = convert_metric_to_write_request(mf, Some(&filter), 0);
         assert_eq!(
             format!("{:?}", write_quest1.timeseries),
-            r#"[TimeSeries { labels: [Label { name: "__name__", value: "filter_counter" }, Label { name: "a", value: "1" }, Label { name: "b", value: "2" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [] }, TimeSeries { labels: [Label { name: "__name__", value: "test_counter" }, Label { name: "a", value: "1" }, Label { name: "b", value: "2" }], samples: [Sample { value: 2.0, timestamp: 0 }], exemplars: [] }]"#
+            r#"[TimeSeries { labels: [Label { name: "__name__", value: "filter_counter" }, Label { name: "a", value: "1" }, Label { name: "b", value: "2" }], samples: [Sample { value: 1.0, timestamp: 0 }], exemplars: [], histograms: [] }, TimeSeries { labels: [Label { name: "__name__", value: "test_counter" }, Label { name: "a", value: "1" }, Label { name: "b", value: "2" }], samples: [Sample { value: 2.0, timestamp: 0 }], exemplars: [], histograms: [] }]"#
         );
         assert_eq!(
             format!("{:?}", write_quest2.timeseries),
-            r#"[TimeSeries { labels: [Label { name: "__name__", value: "test_counter" }, Label { name: "a", value: "1" }, Label { name: "b", value: "2" }], samples: [Sample { value: 2.0, timestamp: 0 }], exemplars: [] }]"#
+            r#"[TimeSeries { labels: [Label { name: "__name__", value: "test_counter" }, Label { name: "a", value: "1" }, Label { name: "b", value: "2" }], samples: [Sample { value: 2.0, timestamp: 0 }], exemplars: [], histograms: [] }]"#
         );
     }
 }

src/common/wal/src/config.rs

@@ -206,6 +206,8 @@ mod tests {
                     client_cert_path: None,
                     client_key_path: None,
                 }),
+                connect_timeout: Duration::from_secs(3),
+                timeout: Duration::from_secs(3),
             },
             kafka_topic: KafkaTopicConfig {
                 num_topics: 32,
@@ -239,6 +241,8 @@ mod tests {
                     client_cert_path: None,
                     client_key_path: None,
                 }),
+                connect_timeout: Duration::from_secs(3),
+                timeout: Duration::from_secs(3),
             },
             max_batch_bytes: ReadableSize::mb(1),
             consumer_wait_timeout: Duration::from_millis(100),

src/common/wal/src/config/kafka/common.rs

@@ -164,6 +164,12 @@ pub struct KafkaConnectionConfig {
     pub sasl: Option<KafkaClientSasl>,
     /// Client TLS config
     pub tls: Option<KafkaClientTls>,
+    /// The connect timeout for kafka client.
+    #[serde(with = "humantime_serde")]
+    pub connect_timeout: Duration,
+    /// The timeout for kafka client.
+    #[serde(with = "humantime_serde")]
+    pub timeout: Duration,
 }
 
 impl Default for KafkaConnectionConfig {
@@ -172,6 +178,8 @@ impl Default for KafkaConnectionConfig {
             broker_endpoints: vec![BROKER_ENDPOINT.to_string()],
             sasl: None,
             tls: None,
+            connect_timeout: Duration::from_secs(3),
+            timeout: Duration::from_secs(3),
         }
     }
 }

src/datanode/src/datanode.rs

@@ -22,6 +22,7 @@ use common_base::Plugins;
 use common_error::ext::BoxedError;
 use common_greptimedb_telemetry::GreptimeDBTelemetryTask;
 use common_meta::cache::{LayeredCacheRegistry, SchemaCacheRef, TableSchemaCacheRef};
+use common_meta::cache_invalidator::CacheInvalidatorRef;
 use common_meta::datanode::TopicStatsReporter;
 use common_meta::key::runtime_switch::RuntimeSwitchManager;
 use common_meta::key::{SchemaMetadataManager, SchemaMetadataManagerRef};
@@ -281,21 +282,11 @@ impl DatanodeBuilder {
             open_all_regions.await?;
         }
 
-        let mut resource_stat = ResourceStatImpl::default();
-        resource_stat.start_collect_cpu_usage();
-
         let heartbeat_task = if let Some(meta_client) = meta_client {
-            Some(
-                HeartbeatTask::try_new(
-                    &self.opts,
-                    region_server.clone(),
-                    meta_client,
-                    cache_registry,
-                    self.plugins.clone(),
-                    Arc::new(resource_stat),
-                )
-                .await?,
-            )
+            let task = self
+                .create_heartbeat_task(&region_server, meta_client, cache_registry)
+                .await?;
+            Some(task)
         } else {
             None
         };
@@ -324,6 +315,29 @@ impl DatanodeBuilder {
         })
     }
 
+    async fn create_heartbeat_task(
+        &self,
+        region_server: &RegionServer,
+        meta_client: MetaClientRef,
+        cache_invalidator: CacheInvalidatorRef,
+    ) -> Result<HeartbeatTask> {
+        let stat = {
+            let mut stat = ResourceStatImpl::default();
+            stat.start_collect_cpu_usage();
+            Arc::new(stat)
+        };
+
+        HeartbeatTask::try_new(
+            &self.opts,
+            region_server.clone(),
+            meta_client,
+            cache_invalidator,
+            self.plugins.clone(),
+            stat,
+        )
+        .await
+    }
+
     /// Builds [ObjectStoreManager] from [StorageConfig].
     pub async fn build_object_store_manager(cfg: &StorageConfig) -> Result<ObjectStoreManagerRef> {
         let object_store = store::new_object_store(cfg.store.clone(), &cfg.data_home).await?;

src/datanode/src/error.rs

@@ -410,14 +410,6 @@ pub enum Error {
         location: Location,
     },
 
-    #[snafu(display("Failed to build cache store"))]
-    BuildCacheStore {
-        #[snafu(source)]
-        error: object_store::Error,
-        #[snafu(implicit)]
-        location: Location,
-    },
-
     #[snafu(display("Not yet implemented: {what}"))]
     NotYetImplemented { what: String },
 }
@@ -493,7 +485,6 @@ impl ErrorExt for Error {
             SerializeJson { .. } => StatusCode::Internal,
 
             ObjectStore { source, .. } => source.status_code(),
-            BuildCacheStore { .. } => StatusCode::StorageUnavailable,
         }
     }
 

src/datanode/src/heartbeat.rs

@@ -25,6 +25,7 @@ use common_meta::datanode::REGION_STATISTIC_KEY;
 use common_meta::distributed_time_constants::META_KEEP_ALIVE_INTERVAL_SECS;
 use common_meta::heartbeat::handler::invalidate_table_cache::InvalidateCacheHandler;
 use common_meta::heartbeat::handler::parse_mailbox_message::ParseMailboxMessageHandler;
+use common_meta::heartbeat::handler::suspend::SuspendHandler;
 use common_meta::heartbeat::handler::{
     HandlerGroupExecutor, HeartbeatResponseHandlerContext, HeartbeatResponseHandlerExecutorRef,
 };
@@ -91,6 +92,7 @@ impl HeartbeatTask {
         let resp_handler_executor = Arc::new(HandlerGroupExecutor::new(vec![
             region_alive_keeper.clone(),
             Arc::new(ParseMailboxMessageHandler),
+            Arc::new(SuspendHandler::new(region_server.suspend_state())),
             Arc::new(
                 RegionHeartbeatResponseHandler::new(region_server.clone())
                     .with_open_region_parallelism(opts.init_regions_parallelism),

src/datanode/src/heartbeat/handler.rs

@@ -99,26 +99,30 @@ impl RegionHeartbeatResponseHandler {
         self
     }
 
-    fn build_handler(&self, instruction: &Instruction) -> MetaResult<Box<InstructionHandlers>> {
+    fn build_handler(
+        &self,
+        instruction: &Instruction,
+    ) -> MetaResult<Option<Box<InstructionHandlers>>> {
         match instruction {
-            Instruction::CloseRegions(_) => Ok(Box::new(CloseRegionsHandler.into())),
-            Instruction::OpenRegions(_) => Ok(Box::new(
+            Instruction::CloseRegions(_) => Ok(Some(Box::new(CloseRegionsHandler.into()))),
+            Instruction::OpenRegions(_) => Ok(Some(Box::new(
                 OpenRegionsHandler {
                     open_region_parallelism: self.open_region_parallelism,
                 }
                 .into(),
-            )),
-            Instruction::FlushRegions(_) => Ok(Box::new(FlushRegionsHandler.into())),
-            Instruction::DowngradeRegions(_) => Ok(Box::new(DowngradeRegionsHandler.into())),
-            Instruction::UpgradeRegions(_) => Ok(Box::new(
+            ))),
+            Instruction::FlushRegions(_) => Ok(Some(Box::new(FlushRegionsHandler.into()))),
+            Instruction::DowngradeRegions(_) => Ok(Some(Box::new(DowngradeRegionsHandler.into()))),
+            Instruction::UpgradeRegions(_) => Ok(Some(Box::new(
                 UpgradeRegionsHandler {
                     upgrade_region_parallelism: self.open_region_parallelism,
                 }
                 .into(),
-            )),
-            Instruction::GetFileRefs(_) => Ok(Box::new(GetFileRefsHandler.into())),
-            Instruction::GcRegions(_) => Ok(Box::new(GcRegionsHandler.into())),
+            ))),
+            Instruction::GetFileRefs(_) => Ok(Some(Box::new(GetFileRefsHandler.into()))),
+            Instruction::GcRegions(_) => Ok(Some(Box::new(GcRegionsHandler.into()))),
             Instruction::InvalidateCaches(_) => InvalidHeartbeatResponseSnafu.fail(),
+            Instruction::Suspend => Ok(None),
         }
     }
 }
@@ -216,30 +220,24 @@ impl HeartbeatResponseHandler for RegionHeartbeatResponseHandler {
             .context(InvalidHeartbeatResponseSnafu)?;
 
         let mailbox = ctx.mailbox.clone();
-        let region_server = self.region_server.clone();
-        let downgrade_tasks = self.downgrade_tasks.clone();
-        let flush_tasks = self.flush_tasks.clone();
-        let gc_tasks = self.gc_tasks.clone();
-        let handler = self.build_handler(&instruction)?;
+        if let Some(handler) = self.build_handler(&instruction)? {
+            let context = HandlerContext {
+                region_server: self.region_server.clone(),
+                downgrade_tasks: self.downgrade_tasks.clone(),
+                flush_tasks: self.flush_tasks.clone(),
+                gc_tasks: self.gc_tasks.clone(),
+            };
             let _handle = common_runtime::spawn_global(async move {
-            let reply = handler
-                .handle(
-                    &HandlerContext {
-                        region_server,
-                        downgrade_tasks,
-                        flush_tasks,
-                        gc_tasks,
-                    },
-                    instruction,
-                )
-                .await;
-
+                let reply = handler.handle(&context, instruction).await;
                 if let Some(reply) = reply
                     && let Err(e) = mailbox.send((meta, reply)).await
                 {
-                error!(e; "Failed to send reply to mailbox");
+                    let error = e.to_string();
+                    let (meta, reply) = e.0;
+                    error!("Failed to send reply {reply} to {meta:?}: {error}");
                 }
             });
+        }
 
         Ok(HandleControl::Continue)
     }

src/datanode/src/region_server.rs

@@ -17,6 +17,7 @@ mod catalog;
 use std::collections::HashMap;
 use std::fmt::Debug;
 use std::ops::Deref;
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, RwLock};
 use std::time::Duration;
 
@@ -52,7 +53,9 @@ pub use query::dummy_catalog::{
     DummyCatalogList, DummyTableProviderFactory, TableProviderFactoryRef,
 };
 use serde_json;
-use servers::error::{self as servers_error, ExecuteGrpcRequestSnafu, Result as ServerResult};
+use servers::error::{
+    self as servers_error, ExecuteGrpcRequestSnafu, Result as ServerResult, SuspendedSnafu,
+};
 use servers::grpc::FlightCompression;
 use servers::grpc::flight::{FlightCraft, FlightRecordBatchStream, TonicStream};
 use servers::grpc::region_server::RegionServerHandler;
@@ -89,6 +92,7 @@ use crate::region_server::catalog::{NameAwareCatalogList, NameAwareDataSourceInj
 pub struct RegionServer {
     inner: Arc<RegionServerInner>,
     flight_compression: FlightCompression,
+    suspend: Arc<AtomicBool>,
 }
 
 pub struct RegionStat {
@@ -136,6 +140,7 @@ impl RegionServer {
                 ),
             )),
             flight_compression,
+            suspend: Arc::new(AtomicBool::new(false)),
         }
     }
 
@@ -595,6 +600,14 @@ impl RegionServer {
             .handle_sync_region(engine_with_status.engine(), region_id, manifest_info)
             .await
     }
+
+    fn is_suspended(&self) -> bool {
+        self.suspend.load(Ordering::Relaxed)
+    }
+
+    pub(crate) fn suspend_state(&self) -> Arc<AtomicBool> {
+        self.suspend.clone()
+    }
 }
 
 #[async_trait]
@@ -644,6 +657,8 @@ impl FlightCraft for RegionServer {
         &self,
         request: Request<Ticket>,
     ) -> TonicResult<Response<TonicStream<FlightData>>> {
+        ensure!(!self.is_suspended(), SuspendedSnafu);
+
         let ticket = request.into_inner().ticket;
         let request = api::v1::region::QueryRequest::decode(ticket.as_ref())
             .context(servers_error::InvalidFlightTicketSnafu)?;

src/datanode/src/store.rs

@@ -14,15 +14,10 @@
 
 //! object storage utilities
 
-use std::sync::Arc;
-
-use common_telemetry::info;
-use object_store::config::ObjectStorageCacheConfig;
+use common_telemetry::{info, warn};
 use object_store::factory::new_raw_object_store;
-use object_store::layers::LruCacheLayer;
-use object_store::services::Fs;
 use object_store::util::{clean_temp_dir, join_dir, with_instrument_layers, with_retry_layers};
-use object_store::{ATOMIC_WRITE_DIR, Access, ObjectStore, ObjectStoreBuilder};
+use object_store::{ATOMIC_WRITE_DIR, ObjectStore};
 use snafu::prelude::*;
 
 use crate::config::ObjectStoreConfig;
@@ -47,23 +42,58 @@ pub(crate) async fn new_object_store_without_cache(
     Ok(object_store)
 }
 
+/// Cleans up old LRU read cache directories that were removed.
+fn clean_old_read_cache(store: &ObjectStoreConfig, data_home: &str) {
+    if !store.is_object_storage() {
+        return;
+    }
+
+    let Some(cache_config) = store.cache_config() else {
+        return;
+    };
+
+    // Only cleans if read cache was enabled
+    if !cache_config.enable_read_cache {
+        return;
+    }
+
+    let cache_base_dir = if cache_config.cache_path.is_empty() {
+        data_home
+    } else {
+        &cache_config.cache_path
+    };
+
+    // Cleans up the old read cache directory
+    let old_read_cache_dir = join_dir(cache_base_dir, "cache/object/read");
+    info!(
+        "Cleaning up old read cache directory: {}",
+        old_read_cache_dir
+    );
+    if let Err(e) = clean_temp_dir(&old_read_cache_dir) {
+        warn!(e; "Failed to clean old read cache directory {}", old_read_cache_dir);
+    }
+
+    // Cleans up the atomic temp dir used by the cache layer
+    let cache_atomic_temp_dir = join_dir(cache_base_dir, ATOMIC_WRITE_DIR);
+    info!(
+        "Cleaning up old cache atomic temp directory: {}",
+        cache_atomic_temp_dir
+    );
+    if let Err(e) = clean_temp_dir(&cache_atomic_temp_dir) {
+        warn!(e; "Failed to clean old cache atomic temp directory {}", cache_atomic_temp_dir);
+    }
+}
+
 pub async fn new_object_store(store: ObjectStoreConfig, data_home: &str) -> Result<ObjectStore> {
+    // Cleans up old LRU read cache directories.
+    // TODO: Remove this line after the 1.0 release.
+    clean_old_read_cache(&store, data_home);
+
     let object_store = new_raw_object_store(&store, data_home)
         .await
         .context(error::ObjectStoreSnafu)?;
-    // Enable retry layer and cache layer for non-fs object storages
+    // Enables retry layer for non-fs object storages
     let object_store = if store.is_object_storage() {
-        let object_store = {
-            // It's safe to unwrap here because we already checked above.
-            let cache_config = store.cache_config().unwrap();
-            if let Some(cache_layer) = build_cache_layer(cache_config, data_home).await? {
-                // Adds cache layer
-                object_store.layer(cache_layer)
-            } else {
-                object_store
-            }
-        };
-
         // Adds retry layer
         with_retry_layers(object_store)
     } else {
@@ -73,40 +103,3 @@ pub async fn new_object_store(store: ObjectStoreConfig, data_home: &str) -> Resu
     let object_store = with_instrument_layers(object_store, true);
     Ok(object_store)
 }
-
-async fn build_cache_layer(
-    cache_config: &ObjectStorageCacheConfig,
-    data_home: &str,
-) -> Result<Option<LruCacheLayer<impl Access>>> {
-    // No need to build cache layer if read cache is disabled.
-    if !cache_config.enable_read_cache {
-        return Ok(None);
-    }
-    let cache_base_dir = if cache_config.cache_path.is_empty() {
-        data_home
-    } else {
-        &cache_config.cache_path
-    };
-    let atomic_temp_dir = join_dir(cache_base_dir, ATOMIC_WRITE_DIR);
-    clean_temp_dir(&atomic_temp_dir).context(error::ObjectStoreSnafu)?;
-
-    let cache_store = Fs::default()
-        .root(cache_base_dir)
-        .atomic_write_dir(&atomic_temp_dir)
-        .build()
-        .context(error::BuildCacheStoreSnafu)?;
-
-    let cache_layer = LruCacheLayer::new(
-        Arc::new(cache_store),
-        cache_config.cache_capacity.0 as usize,
-    )
-    .context(error::BuildCacheStoreSnafu)?;
-    cache_layer.recover_cache(false).await;
-
-    info!(
-        "Enabled local object storage cache, path: {}, capacity: {}.",
-        cache_config.cache_path, cache_config.cache_capacity
-    );
-
-    Ok(Some(cache_layer))
-}

src/datanode/src/tests.rs

@@ -33,9 +33,9 @@ use servers::grpc::FlightCompression;
 use session::context::QueryContextRef;
 use store_api::metadata::RegionMetadataRef;
 use store_api::region_engine::{
-    RegionEngine, RegionManifestInfo, RegionRole, RegionScannerRef, RegionStatistic,
-    RemapManifestsRequest, RemapManifestsResponse, SetRegionRoleStateResponse,
-    SettableRegionRoleState, SyncManifestResponse,
+    CopyRegionFromRequest, CopyRegionFromResponse, RegionEngine, RegionManifestInfo, RegionRole,
+    RegionScannerRef, RegionStatistic, RemapManifestsRequest, RemapManifestsResponse,
+    SetRegionRoleStateResponse, SettableRegionRoleState, SyncManifestResponse,
 };
 use store_api::region_request::{AffectedRows, RegionRequest};
 use store_api::storage::{RegionId, ScanRequest, SequenceNumber};
@@ -299,6 +299,14 @@ impl RegionEngine for MockRegionEngine {
         unimplemented!()
     }
 
+    async fn copy_region_from(
+        &self,
+        _region_id: RegionId,
+        _request: CopyRegionFromRequest,
+    ) -> Result<CopyRegionFromResponse, BoxedError> {
+        unimplemented!()
+    }
+
     fn as_any(&self) -> &dyn Any {
         self
     }

src/datatypes/src/schema.rs

@@ -33,7 +33,8 @@ pub use crate::schema::column_schema::{
     COLUMN_SKIPPING_INDEX_OPT_KEY_FALSE_POSITIVE_RATE, COLUMN_SKIPPING_INDEX_OPT_KEY_GRANULARITY,
     COLUMN_SKIPPING_INDEX_OPT_KEY_TYPE, COMMENT_KEY, ColumnExtType, ColumnSchema, FULLTEXT_KEY,
     FulltextAnalyzer, FulltextBackend, FulltextOptions, INVERTED_INDEX_KEY, Metadata,
-    SKIPPING_INDEX_KEY, SkippingIndexOptions, SkippingIndexType, TIME_INDEX_KEY,
+    SKIPPING_INDEX_KEY, SkippingIndexOptions, SkippingIndexType, TIME_INDEX_KEY, VECTOR_INDEX_KEY,
+    VectorDistanceMetric, VectorIndexEngineType, VectorIndexOptions,
 };
 pub use crate::schema::constraint::ColumnDefaultConstraint;
 pub use crate::schema::raw::RawSchema;

src/datatypes/src/schema/column_schema.rs

@@ -46,6 +46,8 @@ pub const FULLTEXT_KEY: &str = "greptime:fulltext";
 pub const INVERTED_INDEX_KEY: &str = "greptime:inverted_index";
 /// Key used to store skip options in arrow field's metadata.
 pub const SKIPPING_INDEX_KEY: &str = "greptime:skipping_index";
+/// Key used to store vector index options in arrow field's metadata.
+pub const VECTOR_INDEX_KEY: &str = "greptime:vector_index";
 
 /// Keys used in fulltext options
 pub const COLUMN_FULLTEXT_CHANGE_OPT_KEY_ENABLE: &str = "enable";
@@ -216,6 +218,53 @@ impl ColumnSchema {
         self.metadata.contains_key(INVERTED_INDEX_KEY)
     }
 
+    /// Checks if this column has a vector index.
+    pub fn is_vector_indexed(&self) -> bool {
+        match self.vector_index_options() {
+            Ok(opts) => opts.is_some(),
+            Err(e) => {
+                common_telemetry::warn!(
+                    "Failed to deserialize vector_index_options for column '{}': {}",
+                    self.name,
+                    e
+                );
+                false
+            }
+        }
+    }
+
+    /// Gets the vector index options.
+    pub fn vector_index_options(&self) -> Result<Option<VectorIndexOptions>> {
+        match self.metadata.get(VECTOR_INDEX_KEY) {
+            None => Ok(None),
+            Some(json) => {
+                let options =
+                    serde_json::from_str(json).context(error::DeserializeSnafu { json })?;
+                Ok(Some(options))
+            }
+        }
+    }
+
+    /// Sets the vector index options.
+    pub fn set_vector_index_options(&mut self, options: &VectorIndexOptions) -> Result<()> {
+        self.metadata.insert(
+            VECTOR_INDEX_KEY.to_string(),
+            serde_json::to_string(options).context(error::SerializeSnafu)?,
+        );
+        Ok(())
+    }
+
+    /// Removes the vector index options.
+    pub fn unset_vector_index_options(&mut self) {
+        self.metadata.remove(VECTOR_INDEX_KEY);
+    }
+
+    /// Sets vector index options and returns self for chaining.
+    pub fn with_vector_index_options(mut self, options: &VectorIndexOptions) -> Result<Self> {
+        self.set_vector_index_options(options)?;
+        Ok(self)
+    }
+
     /// Set default constraint.
     ///
     /// If a default constraint exists for the column, this method will
@@ -964,6 +1013,181 @@ impl TryFrom<HashMap<String, String>> for SkippingIndexOptions {
     }
 }
 
+/// Distance metric for vector similarity search.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default, Visit, VisitMut)]
+#[serde(rename_all = "lowercase")]
+pub enum VectorDistanceMetric {
+    /// Squared Euclidean distance (L2^2).
+    #[default]
+    L2sq,
+    /// Cosine distance (1 - cosine similarity).
+    Cosine,
+    /// Inner product (negative, for maximum inner product search).
+    #[serde(alias = "ip")]
+    InnerProduct,
+}
+
+impl fmt::Display for VectorDistanceMetric {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            VectorDistanceMetric::L2sq => write!(f, "l2sq"),
+            VectorDistanceMetric::Cosine => write!(f, "cosine"),
+            VectorDistanceMetric::InnerProduct => write!(f, "ip"),
+        }
+    }
+}
+
+impl std::str::FromStr for VectorDistanceMetric {
+    type Err = String;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        match s.to_lowercase().as_str() {
+            "l2sq" | "l2" | "euclidean" => Ok(VectorDistanceMetric::L2sq),
+            "cosine" | "cos" => Ok(VectorDistanceMetric::Cosine),
+            "inner_product" | "ip" | "dot" => Ok(VectorDistanceMetric::InnerProduct),
+            _ => Err(format!(
+                "Unknown distance metric: {}. Expected: l2sq, cosine, or ip",
+                s
+            )),
+        }
+    }
+}
+
+impl VectorDistanceMetric {
+    /// Returns the metric as u8 for blob serialization.
+    pub fn as_u8(&self) -> u8 {
+        match self {
+            Self::L2sq => 0,
+            Self::Cosine => 1,
+            Self::InnerProduct => 2,
+        }
+    }
+
+    /// Parses metric from u8 (used when reading blob).
+    pub fn try_from_u8(v: u8) -> Option<Self> {
+        match v {
+            0 => Some(Self::L2sq),
+            1 => Some(Self::Cosine),
+            2 => Some(Self::InnerProduct),
+            _ => None,
+        }
+    }
+}
+
+/// Default HNSW connectivity parameter.
+const DEFAULT_VECTOR_INDEX_CONNECTIVITY: u32 = 16;
+/// Default expansion factor during index construction.
+const DEFAULT_VECTOR_INDEX_EXPANSION_ADD: u32 = 128;
+/// Default expansion factor during search.
+const DEFAULT_VECTOR_INDEX_EXPANSION_SEARCH: u32 = 64;
+
+fn default_vector_index_connectivity() -> u32 {
+    DEFAULT_VECTOR_INDEX_CONNECTIVITY
+}
+
+fn default_vector_index_expansion_add() -> u32 {
+    DEFAULT_VECTOR_INDEX_EXPANSION_ADD
+}
+
+fn default_vector_index_expansion_search() -> u32 {
+    DEFAULT_VECTOR_INDEX_EXPANSION_SEARCH
+}
+
+/// Supported vector index engine types.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default, Serialize, Deserialize, Visit, VisitMut)]
+#[serde(rename_all = "lowercase")]
+pub enum VectorIndexEngineType {
+    /// USearch HNSW implementation.
+    #[default]
+    Usearch,
+    // Future: Vsag,
+}
+
+impl VectorIndexEngineType {
+    /// Returns the engine type as u8 for blob serialization.
+    pub fn as_u8(&self) -> u8 {
+        match self {
+            Self::Usearch => 0,
+        }
+    }
+
+    /// Parses engine type from u8 (used when reading blob).
+    pub fn try_from_u8(v: u8) -> Option<Self> {
+        match v {
+            0 => Some(Self::Usearch),
+            _ => None,
+        }
+    }
+}
+
+impl fmt::Display for VectorIndexEngineType {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Usearch => write!(f, "usearch"),
+        }
+    }
+}
+
+impl std::str::FromStr for VectorIndexEngineType {
+    type Err = String;
+
+    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
+        match s.to_lowercase().as_str() {
+            "usearch" => Ok(Self::Usearch),
+            _ => Err(format!(
+                "Unknown vector index engine: {}. Expected: usearch",
+                s
+            )),
+        }
+    }
+}
+
+/// Options for vector index (HNSW).
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Visit, VisitMut)]
+#[serde(rename_all = "kebab-case")]
+pub struct VectorIndexOptions {
+    /// Vector index engine type (default: usearch).
+    #[serde(default)]
+    pub engine: VectorIndexEngineType,
+    /// Distance metric for similarity search.
+    #[serde(default)]
+    pub metric: VectorDistanceMetric,
+    /// HNSW connectivity parameter (M in the paper).
+    /// Higher values improve recall but increase memory usage.
+    #[serde(default = "default_vector_index_connectivity")]
+    pub connectivity: u32,
+    /// Expansion factor during index construction (ef_construction).
+    /// Higher values improve index quality but slow down construction.
+    #[serde(default = "default_vector_index_expansion_add")]
+    pub expansion_add: u32,
+    /// Expansion factor during search (ef_search).
+    /// Higher values improve recall but slow down search.
+    #[serde(default = "default_vector_index_expansion_search")]
+    pub expansion_search: u32,
+}
+
+impl Default for VectorIndexOptions {
+    fn default() -> Self {
+        Self {
+            engine: VectorIndexEngineType::default(),
+            metric: VectorDistanceMetric::default(),
+            connectivity: DEFAULT_VECTOR_INDEX_CONNECTIVITY,
+            expansion_add: DEFAULT_VECTOR_INDEX_EXPANSION_ADD,
+            expansion_search: DEFAULT_VECTOR_INDEX_EXPANSION_SEARCH,
+        }
+    }
+}
+
+impl fmt::Display for VectorIndexOptions {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "engine={}, metric={}, connectivity={}, expansion_add={}, expansion_search={}",
+            self.engine, self.metric, self.connectivity, self.expansion_add, self.expansion_search
+        )
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::sync::Arc;

src/file-engine/src/engine.rs

@@ -26,10 +26,10 @@ use object_store::ObjectStore;
 use snafu::{OptionExt, ensure};
 use store_api::metadata::RegionMetadataRef;
 use store_api::region_engine::{
-    RegionEngine, RegionManifestInfo, RegionRole, RegionScannerRef, RegionStatistic,
-    RemapManifestsRequest, RemapManifestsResponse, SetRegionRoleStateResponse,
-    SetRegionRoleStateSuccess, SettableRegionRoleState, SinglePartitionScanner,
-    SyncManifestResponse,
+    CopyRegionFromRequest, CopyRegionFromResponse, RegionEngine, RegionManifestInfo, RegionRole,
+    RegionScannerRef, RegionStatistic, RemapManifestsRequest, RemapManifestsResponse,
+    SetRegionRoleStateResponse, SetRegionRoleStateSuccess, SettableRegionRoleState,
+    SinglePartitionScanner, SyncManifestResponse,
 };
 use store_api::region_request::{
     AffectedRows, RegionCloseRequest, RegionCreateRequest, RegionDropRequest, RegionOpenRequest,
@@ -163,6 +163,19 @@ impl RegionEngine for FileRegionEngine {
         ))
     }
 
+    async fn copy_region_from(
+        &self,
+        _region_id: RegionId,
+        _request: CopyRegionFromRequest,
+    ) -> Result<CopyRegionFromResponse, BoxedError> {
+        Err(BoxedError::new(
+            UnsupportedSnafu {
+                operation: "copy_region_from",
+            }
+            .build(),
+        ))
+    }
+
     fn role(&self, region_id: RegionId) -> Option<RegionRole> {
         self.inner.state(region_id)
     }

src/flow/src/batching_mode/frontend_client.rs

@@ -15,7 +15,7 @@
 //! Frontend client to run flow as batching task which is time-window-aware normal query triggered every tick set by user
 
 use std::collections::HashMap;
-use std::sync::{Arc, Weak};
+use std::sync::{Arc, Mutex, Weak};
 use std::time::SystemTime;
 
 use api::v1::greptime_request::Request;
@@ -38,6 +38,7 @@ use servers::query_handler::grpc::GrpcQueryHandler;
 use session::context::{QueryContextBuilder, QueryContextRef};
 use session::hints::READ_PREFERENCE_HINT;
 use snafu::{OptionExt, ResultExt};
+use tokio::sync::SetOnce;
 
 use crate::batching_mode::BatchingModeOptions;
 use crate::error::{
@@ -75,7 +76,19 @@ impl<E: ErrorExt + Send + Sync + 'static, T: GrpcQueryHandler<Error = E> + Send
     }
 }
 
-type HandlerMutable = Arc<std::sync::Mutex<Option<Weak<dyn GrpcQueryHandlerWithBoxedError>>>>;
+#[derive(Debug, Clone)]
+pub struct HandlerMutable {
+    handler: Arc<Mutex<Option<Weak<dyn GrpcQueryHandlerWithBoxedError>>>>,
+    is_initialized: Arc<SetOnce<()>>,
+}
+
+impl HandlerMutable {
+    pub async fn set_handler(&self, handler: Weak<dyn GrpcQueryHandlerWithBoxedError>) {
+        *self.handler.lock().unwrap() = Some(handler);
+        // Ignore the error, as we allow the handler to be set multiple times.
+        let _ = self.is_initialized.set(());
+    }
+}
 
 /// A simple frontend client able to execute sql using grpc protocol
 ///
@@ -100,7 +113,11 @@ pub enum FrontendClient {
 impl FrontendClient {
     /// Create a new empty frontend client, with a `HandlerMutable` to set the grpc handler later
     pub fn from_empty_grpc_handler(query: QueryOptions) -> (Self, HandlerMutable) {
-        let handler = Arc::new(std::sync::Mutex::new(None));
+        let is_initialized = Arc::new(SetOnce::new());
+        let handler = HandlerMutable {
+            handler: Arc::new(Mutex::new(None)),
+            is_initialized,
+        };
         (
             Self::Standalone {
                 database_client: handler.clone(),
@@ -110,6 +127,16 @@ impl FrontendClient {
         )
     }
 
+    /// Waits until the frontend client is initialized.
+    pub async fn wait_initialized(&self) {
+        if let FrontendClient::Standalone {
+            database_client, ..
+        } = self
+        {
+            database_client.is_initialized.wait().await;
+        }
+    }
+
     pub fn from_meta_client(
         meta_client: Arc<MetaClient>,
         auth: Option<FlowAuthHeader>,
@@ -138,8 +165,14 @@ impl FrontendClient {
         grpc_handler: Weak<dyn GrpcQueryHandlerWithBoxedError>,
         query: QueryOptions,
     ) -> Self {
+        let is_initialized = Arc::new(SetOnce::new_with(Some(())));
+        let handler = HandlerMutable {
+            handler: Arc::new(Mutex::new(Some(grpc_handler))),
+            is_initialized: is_initialized.clone(),
+        };
+
         Self::Standalone {
-            database_client: Arc::new(std::sync::Mutex::new(Some(grpc_handler))),
+            database_client: handler,
             query,
         }
     }
@@ -321,6 +354,7 @@ impl FrontendClient {
                 {
                     let database_client = {
                         database_client
+                            .handler
                             .lock()
                             .map_err(|e| {
                                 UnexpectedSnafu {
@@ -398,6 +432,7 @@ impl FrontendClient {
                 {
                     let database_client = {
                         database_client
+                            .handler
                             .lock()
                             .map_err(|e| {
                                 UnexpectedSnafu {
@@ -460,3 +495,73 @@ impl std::fmt::Display for PeerDesc {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use std::time::Duration;
+
+    use common_query::Output;
+    use tokio::time::timeout;
+
+    use super::*;
+
+    #[derive(Debug)]
+    struct NoopHandler;
+
+    #[async_trait::async_trait]
+    impl GrpcQueryHandlerWithBoxedError for NoopHandler {
+        async fn do_query(
+            &self,
+            _query: Request,
+            _ctx: QueryContextRef,
+        ) -> std::result::Result<Output, BoxedError> {
+            Ok(Output::new_with_affected_rows(0))
+        }
+    }
+
+    #[tokio::test]
+    async fn wait_initialized() {
+        let (client, handler_mut) =
+            FrontendClient::from_empty_grpc_handler(QueryOptions::default());
+
+        assert!(
+            timeout(Duration::from_millis(50), client.wait_initialized())
+                .await
+                .is_err()
+        );
+
+        let handler: Arc<dyn GrpcQueryHandlerWithBoxedError> = Arc::new(NoopHandler);
+        handler_mut.set_handler(Arc::downgrade(&handler)).await;
+
+        timeout(Duration::from_secs(1), client.wait_initialized())
+            .await
+            .expect("wait_initialized should complete after handler is set");
+
+        timeout(Duration::from_millis(10), client.wait_initialized())
+            .await
+            .expect("wait_initialized should be a no-op once initialized");
+
+        let handler: Arc<dyn GrpcQueryHandlerWithBoxedError> = Arc::new(NoopHandler);
+        let client =
+            FrontendClient::from_grpc_handler(Arc::downgrade(&handler), QueryOptions::default());
+        assert!(
+            timeout(Duration::from_millis(10), client.wait_initialized())
+                .await
+                .is_ok()
+        );
+
+        let meta_client = Arc::new(MetaClient::default());
+        let client = FrontendClient::from_meta_client(
+            meta_client,
+            None,
+            QueryOptions::default(),
+            BatchingModeOptions::default(),
+        )
+        .unwrap();
+        assert!(
+            timeout(Duration::from_millis(10), client.wait_initialized())
+                .await
+                .is_ok()
+        );
+    }
+}

src/flow/src/server.rs

@@ -490,7 +490,6 @@ impl<'a> FlownodeServiceBuilder<'a> {
         let config = GrpcServerConfig {
             max_recv_message_size: opts.grpc.max_recv_message_size.as_bytes() as usize,
             max_send_message_size: opts.grpc.max_send_message_size.as_bytes() as usize,
-            max_total_message_memory: opts.grpc.max_total_message_memory.as_bytes() as usize,
             tls: opts.grpc.tls.clone(),
             max_connection_age: opts.grpc.max_connection_age,
         };

src/frontend/Cargo.toml

@@ -17,6 +17,7 @@ arc-swap = "1.0"
 async-stream.workspace = true
 async-trait.workspace = true
 auth.workspace = true
+axum.workspace = true
 bytes.workspace = true
 cache.workspace = true
 catalog.workspace = true
@@ -31,6 +32,7 @@ common-frontend.workspace = true
 common-function.workspace = true
 common-grpc.workspace = true
 common-macro.workspace = true
+common-memory-manager.workspace = true
 common-meta.workspace = true
 common-options.workspace = true
 common-procedure.workspace = true
@@ -85,6 +87,9 @@ common-test-util.workspace = true
 datanode.workspace = true
 datatypes.workspace = true
 futures.workspace = true
+hyper-util = { workspace = true, features = ["tokio"] }
+meta-srv.workspace = true
+reqwest.workspace = true
 serde_json.workspace = true
 strfmt = "0.2"
 tower.workspace = true

src/frontend/src/error.rs

@@ -357,10 +357,8 @@ pub enum Error {
         location: Location,
     },
 
-    #[snafu(display("Failed to acquire more permits from limiter"))]
-    AcquireLimiter {
-        #[snafu(source)]
-        error: tokio::sync::AcquireError,
+    #[snafu(display("Service suspended"))]
+    Suspended {
         #[snafu(implicit)]
         location: Location,
     },
@@ -443,7 +441,7 @@ impl ErrorExt for Error {
 
             Error::StatementTimeout { .. } => StatusCode::Cancelled,
 
-            Error::AcquireLimiter { .. } => StatusCode::Internal,
+            Error::Suspended { .. } => StatusCode::Suspended,
         }
     }
 

src/frontend/src/frontend.rs

@@ -17,6 +17,7 @@ use std::sync::Arc;
 use common_base::readable_size::ReadableSize;
 use common_config::config::Configurable;
 use common_event_recorder::EventRecorderOptions;
+use common_memory_manager::OnExhaustedPolicy;
 use common_options::datanode::DatanodeClientOptions;
 use common_options::memory::MemoryOptions;
 use common_telemetry::logging::{LoggingOptions, SlowQueryOptions, TracingOptions};
@@ -45,6 +46,12 @@ pub struct FrontendOptions {
     pub default_timezone: Option<String>,
     pub default_column_prefix: Option<String>,
     pub heartbeat: HeartbeatOptions,
+    /// Maximum total memory for all concurrent write request bodies and messages (HTTP, gRPC, Flight).
+    /// Set to 0 to disable the limit. Default: "0" (unlimited)
+    pub max_in_flight_write_bytes: ReadableSize,
+    /// Policy when write bytes quota is exhausted.
+    /// Options: "wait" (default, 10s), "wait(<duration>)", "fail"
+    pub write_bytes_exhausted_policy: OnExhaustedPolicy,
     pub http: HttpOptions,
     pub grpc: GrpcOptions,
     /// The internal gRPC options for the frontend service.
@@ -63,7 +70,6 @@ pub struct FrontendOptions {
     pub user_provider: Option<String>,
     pub tracing: TracingOptions,
     pub query: QueryOptions,
-    pub max_in_flight_write_bytes: Option<ReadableSize>,
     pub slow_query: SlowQueryOptions,
     pub memory: MemoryOptions,
     /// The event recorder options.
@@ -77,6 +83,8 @@ impl Default for FrontendOptions {
             default_timezone: None,
             default_column_prefix: None,
             heartbeat: HeartbeatOptions::frontend_default(),
+            max_in_flight_write_bytes: ReadableSize(0),
+            write_bytes_exhausted_policy: OnExhaustedPolicy::default(),
             http: HttpOptions::default(),
             grpc: GrpcOptions::default(),
             internal_grpc: None,
@@ -93,7 +101,6 @@ impl Default for FrontendOptions {
             user_provider: None,
             tracing: TracingOptions::default(),
             query: QueryOptions::default(),
-            max_in_flight_write_bytes: None,
             slow_query: SlowQueryOptions::default(),
             memory: MemoryOptions::default(),
             event_recorder: EventRecorderOptions::default(),
@@ -141,7 +148,42 @@ impl Frontend {
 
 #[cfg(test)]
 mod tests {
+    use std::sync::atomic::{AtomicBool, Ordering};
+    use std::time::Duration;
+
+    use api::v1::meta::heartbeat_server::HeartbeatServer;
+    use api::v1::meta::mailbox_message::Payload;
+    use api::v1::meta::{
+        AskLeaderRequest, AskLeaderResponse, HeartbeatRequest, HeartbeatResponse, MailboxMessage,
+        Peer, ResponseHeader, Role, heartbeat_server,
+    };
+    use async_trait::async_trait;
+    use client::{Client, Database};
+    use common_catalog::consts::{DEFAULT_CATALOG_NAME, DEFAULT_SCHEMA_NAME};
+    use common_error::ext::ErrorExt;
+    use common_error::from_header_to_err_code_msg;
+    use common_error::status_code::StatusCode;
+    use common_grpc::channel_manager::ChannelManager;
+    use common_meta::heartbeat::handler::HandlerGroupExecutor;
+    use common_meta::heartbeat::handler::parse_mailbox_message::ParseMailboxMessageHandler;
+    use common_meta::heartbeat::handler::suspend::SuspendHandler;
+    use common_meta::instruction::Instruction;
+    use common_stat::ResourceStatImpl;
+    use meta_client::MetaClientRef;
+    use meta_client::client::MetaClientBuilder;
+    use meta_srv::service::GrpcStream;
+    use servers::grpc::{FlightCompression, GRPC_SERVER};
+    use servers::http::HTTP_SERVER;
+    use servers::http::result::greptime_result_v1::GreptimedbV1Response;
+    use tokio::sync::mpsc;
+    use tonic::codec::CompressionEncoding;
+    use tonic::codegen::tokio_stream::StreamExt;
+    use tonic::codegen::tokio_stream::wrappers::ReceiverStream;
+    use tonic::{Request, Response, Status, Streaming};
+
     use super::*;
+    use crate::instance::builder::FrontendBuilder;
+    use crate::server::Services;
 
     #[test]
     fn test_toml() {
@@ -149,4 +191,282 @@ mod tests {
         let toml_string = toml::to_string(&opts).unwrap();
         let _parsed: FrontendOptions = toml::from_str(&toml_string).unwrap();
     }
+
+    struct SuspendableHeartbeatServer {
+        suspend: Arc<AtomicBool>,
+    }
+
+    #[async_trait]
+    impl heartbeat_server::Heartbeat for SuspendableHeartbeatServer {
+        type HeartbeatStream = GrpcStream<HeartbeatResponse>;
+
+        async fn heartbeat(
+            &self,
+            request: Request<Streaming<HeartbeatRequest>>,
+        ) -> std::result::Result<Response<Self::HeartbeatStream>, Status> {
+            let (tx, rx) = mpsc::channel(4);
+
+            common_runtime::spawn_global({
+                let mut requests = request.into_inner();
+                let suspend = self.suspend.clone();
+                async move {
+                    while let Some(request) = requests.next().await {
+                        if let Err(e) = request {
+                            let _ = tx.send(Err(e)).await;
+                            return;
+                        }
+
+                        let mailbox_message =
+                            suspend.load(Ordering::Relaxed).then(|| MailboxMessage {
+                                payload: Some(Payload::Json(
+                                    serde_json::to_string(&Instruction::Suspend).unwrap(),
+                                )),
+                                ..Default::default()
+                            });
+                        let response = HeartbeatResponse {
+                            header: Some(ResponseHeader::success()),
+                            mailbox_message,
+                            ..Default::default()
+                        };
+
+                        let _ = tx.send(Ok(response)).await;
+                    }
+                }
+            });
+
+            Ok(Response::new(Box::pin(ReceiverStream::new(rx))))
+        }
+
+        async fn ask_leader(
+            &self,
+            _: Request<AskLeaderRequest>,
+        ) -> std::result::Result<Response<AskLeaderResponse>, Status> {
+            Ok(Response::new(AskLeaderResponse {
+                header: Some(ResponseHeader::success()),
+                leader: Some(Peer {
+                    addr: "localhost:0".to_string(),
+                    ..Default::default()
+                }),
+            }))
+        }
+    }
+
+    async fn create_meta_client(
+        options: &MetaClientOptions,
+        heartbeat_server: Arc<SuspendableHeartbeatServer>,
+    ) -> MetaClientRef {
+        let (client, server) = tokio::io::duplex(1024);
+
+        // create the heartbeat server:
+        common_runtime::spawn_global(async move {
+            let mut router = tonic::transport::Server::builder();
+            let router = router.add_service(
+                HeartbeatServer::from_arc(heartbeat_server)
+                    .accept_compressed(CompressionEncoding::Zstd)
+                    .send_compressed(CompressionEncoding::Zstd),
+            );
+            router
+                .serve_with_incoming(futures::stream::iter([Ok::<_, std::io::Error>(server)]))
+                .await
+        });
+
+        // Move client to an option so we can _move_ the inner value
+        // on the first attempt to connect. All other attempts will fail.
+        let mut client = Some(client);
+        let connector = tower::service_fn(move |_| {
+            let client = client.take();
+            async move {
+                if let Some(client) = client {
+                    Ok(hyper_util::rt::TokioIo::new(client))
+                } else {
+                    Err(std::io::Error::other("client already taken"))
+                }
+            }
+        });
+        let manager = ChannelManager::new();
+        manager
+            .reset_with_connector("localhost:0", connector)
+            .unwrap();
+
+        // create the heartbeat client:
+        let mut client = MetaClientBuilder::new(0, Role::Frontend)
+            .enable_heartbeat()
+            .heartbeat_channel_manager(manager)
+            .build();
+        client.start(&options.metasrv_addrs).await.unwrap();
+        Arc::new(client)
+    }
+
+    async fn create_frontend(
+        options: &FrontendOptions,
+        meta_client: MetaClientRef,
+    ) -> Result<Frontend> {
+        let instance = Arc::new(
+            FrontendBuilder::new_test(options, meta_client.clone())
+                .try_build()
+                .await?,
+        );
+
+        let servers =
+            Services::new(options.clone(), instance.clone(), Default::default()).build()?;
+
+        let executor = Arc::new(HandlerGroupExecutor::new(vec![
+            Arc::new(ParseMailboxMessageHandler),
+            Arc::new(SuspendHandler::new(instance.suspend_state())),
+        ]));
+        let heartbeat_task = Some(HeartbeatTask::new(
+            options,
+            meta_client,
+            executor,
+            Arc::new(ResourceStatImpl::default()),
+        ));
+
+        let mut frontend = Frontend {
+            instance,
+            servers,
+            heartbeat_task,
+        };
+        frontend.start().await?;
+        Ok(frontend)
+    }
+
+    async fn verify_suspend_state_by_http(
+        frontend: &Frontend,
+        expected: std::result::Result<&str, (StatusCode, &str)>,
+    ) {
+        let addr = frontend.server_handlers().addr(HTTP_SERVER).unwrap();
+        let response = reqwest::get(format!("http://{}/v1/sql?sql=SELECT 1", addr))
+            .await
+            .unwrap();
+
+        let headers = response.headers();
+        let response = if let Some((code, error)) = from_header_to_err_code_msg(headers) {
+            Err((code, error))
+        } else {
+            Ok(response.text().await.unwrap())
+        };
+
+        match (response, expected) {
+            (Ok(response), Ok(expected)) => {
+                let response: GreptimedbV1Response = serde_json::from_str(&response).unwrap();
+                let response = serde_json::to_string(response.output()).unwrap();
+                assert_eq!(&response, expected);
+            }
+            (Err(actual), Err(expected)) => assert_eq!(actual, expected),
+            _ => unreachable!(),
+        }
+    }
+
+    async fn verify_suspend_state_by_grpc(
+        frontend: &Frontend,
+        expected: std::result::Result<&str, (StatusCode, &str)>,
+    ) {
+        let addr = frontend.server_handlers().addr(GRPC_SERVER).unwrap();
+        let client = Client::with_urls([addr.to_string()]);
+        let client = Database::new(DEFAULT_CATALOG_NAME, DEFAULT_SCHEMA_NAME, client);
+        let response = client.sql("SELECT 1").await;
+
+        match (response, expected) {
+            (Ok(response), Ok(expected)) => {
+                let response = response.data.pretty_print().await;
+                assert_eq!(&response, expected.trim());
+            }
+            (Err(actual), Err(expected)) => {
+                assert_eq!(actual.status_code(), expected.0);
+                assert_eq!(actual.output_msg(), expected.1);
+            }
+            _ => unreachable!(),
+        }
+    }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+    async fn test_suspend_frontend() -> Result<()> {
+        common_telemetry::init_default_ut_logging();
+
+        let meta_client_options = MetaClientOptions {
+            metasrv_addrs: vec!["localhost:0".to_string()],
+            ..Default::default()
+        };
+        let options = FrontendOptions {
+            http: HttpOptions {
+                addr: "127.0.0.1:0".to_string(),
+                ..Default::default()
+            },
+            grpc: GrpcOptions {
+                bind_addr: "127.0.0.1:0".to_string(),
+                flight_compression: FlightCompression::None,
+                ..Default::default()
+            },
+            mysql: MysqlOptions {
+                enable: false,
+                ..Default::default()
+            },
+            postgres: PostgresOptions {
+                enable: false,
+                ..Default::default()
+            },
+            meta_client: Some(meta_client_options.clone()),
+            heartbeat: HeartbeatOptions {
+                interval: Duration::from_secs(1),
+                ..Default::default()
+            },
+            ..Default::default()
+        };
+
+        let server = Arc::new(SuspendableHeartbeatServer {
+            suspend: Arc::new(AtomicBool::new(false)),
+        });
+        let meta_client = create_meta_client(&meta_client_options, server.clone()).await;
+        let frontend = create_frontend(&options, meta_client).await?;
+
+        let frontend_heartbeat_interval = options.heartbeat.interval;
+        tokio::time::sleep(frontend_heartbeat_interval).await;
+        // initial state: not suspend:
+        assert!(!frontend.instance.is_suspended());
+        verify_suspend_state_by_http(&frontend, Ok(r#"[{"records":{"schema":{"column_schemas":[{"name":"Int64(1)","data_type":"Int64"}]},"rows":[[1]],"total_rows":1}}]"#)).await;
+        verify_suspend_state_by_grpc(
+            &frontend,
+            Ok(r#"
++----------+
+| Int64(1) |
++----------+
+| 1        |
++----------+"#),
+        )
+        .await;
+
+        // make heartbeat server returned "suspend" instruction,
+        server.suspend.store(true, Ordering::Relaxed);
+        tokio::time::sleep(frontend_heartbeat_interval).await;
+        // ... then the frontend is suspended:
+        assert!(frontend.instance.is_suspended());
+        verify_suspend_state_by_http(
+            &frontend,
+            Err((
+                StatusCode::Suspended,
+                "error: Service suspended, execution_time_ms: 0",
+            )),
+        )
+        .await;
+        verify_suspend_state_by_grpc(&frontend, Err((StatusCode::Suspended, "Service suspended")))
+            .await;
+
+        // make heartbeat server NOT returned "suspend" instruction,
+        server.suspend.store(false, Ordering::Relaxed);
+        tokio::time::sleep(frontend_heartbeat_interval).await;
+        // ... then frontend's suspend state is cleared:
+        assert!(!frontend.instance.is_suspended());
+        verify_suspend_state_by_http(&frontend, Ok(r#"[{"records":{"schema":{"column_schemas":[{"name":"Int64(1)","data_type":"Int64"}]},"rows":[[1]],"total_rows":1}}]"#)).await;
+        verify_suspend_state_by_grpc(
+            &frontend,
+            Ok(r#"
++----------+
+| Int64(1) |
++----------+
+| 1        |
++----------+"#),
+        )
+        .await;
+        Ok(())
+    }
 }

src/frontend/src/heartbeat.rs

@@ -27,7 +27,6 @@ use common_stat::ResourceStatRef;
 use common_telemetry::{debug, error, info, warn};
 use meta_client::client::{HeartbeatSender, HeartbeatStream, MetaClient};
 use servers::addrs;
-use servers::heartbeat_options::HeartbeatOptions;
 use snafu::ResultExt;
 use tokio::sync::mpsc;
 use tokio::sync::mpsc::Receiver;
@@ -54,7 +53,6 @@ impl HeartbeatTask {
     pub fn new(
         opts: &FrontendOptions,
         meta_client: Arc<MetaClient>,
-        heartbeat_opts: HeartbeatOptions,
         resp_handler_executor: HeartbeatResponseHandlerExecutorRef,
         resource_stat: ResourceStatRef,
     ) -> Self {
@@ -68,8 +66,8 @@ impl HeartbeatTask {
                 addrs::resolve_addr(&opts.grpc.bind_addr, Some(&opts.grpc.server_addr))
             },
             meta_client,
-            report_interval: heartbeat_opts.interval,
-            retry_interval: heartbeat_opts.retry_interval,
+            report_interval: opts.heartbeat.interval,
+            retry_interval: opts.heartbeat.retry_interval,
             resp_handler_executor,
             start_time_ms: common_time::util::current_time_millis() as u64,
             resource_stat,
@@ -196,7 +194,8 @@ impl HeartbeatTask {
         let report_interval = self.report_interval;
         let start_time_ms = self.start_time_ms;
         let self_peer = Some(Peer {
-            // The peer id doesn't make sense for frontend, so we just set it 0.
+            // The node id will be actually calculated from its address (by hashing the address
+            // string) in the metasrv. So it can be set to 0 here, as a placeholder.
             id: 0,
             addr: self.peer_addr.clone(),
         });

src/frontend/src/instance.rs

@@ -26,7 +26,8 @@ mod region_query;
 pub mod standalone;
 
 use std::pin::Pin;
-use std::sync::Arc;
+use std::sync::atomic::AtomicBool;
+use std::sync::{Arc, atomic};
 use std::time::{Duration, SystemTime};
 
 use async_stream::stream;
@@ -83,6 +84,7 @@ use snafu::prelude::*;
 use sql::ast::ObjectNamePartExt;
 use sql::dialect::Dialect;
 use sql::parser::{ParseOptions, ParserContext};
+use sql::statements::comment::CommentObject;
 use sql::statements::copy::{CopyDatabase, CopyTable};
 use sql::statements::statement::Statement;
 use sql::statements::tql::Tql;
@@ -95,7 +97,6 @@ use crate::error::{
     ParseSqlSnafu, PermissionSnafu, PlanStatementSnafu, Result, SqlExecInterceptedSnafu,
     StatementTimeoutSnafu, TableOperationSnafu,
 };
-use crate::limiter::LimiterRef;
 use crate::stream_wrapper::CancellableStreamWrapper;
 
 lazy_static! {
@@ -116,9 +117,9 @@ pub struct Instance {
     deleter: DeleterRef,
     table_metadata_manager: TableMetadataManagerRef,
     event_recorder: Option<EventRecorderRef>,
-    limiter: Option<LimiterRef>,
     process_manager: ProcessManagerRef,
     slow_query_options: SlowQueryOptions,
+    suspend: Arc<AtomicBool>,
 
     // cache for otlp metrics
     // first layer key: db-string
@@ -171,6 +172,14 @@ impl Instance {
     pub fn procedure_executor(&self) -> &ProcedureExecutorRef {
         self.statement_executor.procedure_executor()
     }
+
+    pub fn suspend_state(&self) -> Arc<AtomicBool> {
+        self.suspend.clone()
+    }
+
+    pub(crate) fn is_suspended(&self) -> bool {
+        self.suspend.load(atomic::Ordering::Relaxed)
+    }
 }
 
 fn parse_stmt(sql: &str, dialect: &(dyn Dialect + Send + Sync)) -> Result<Vec<Statement>> {
@@ -513,6 +522,10 @@ impl SqlQueryHandler for Instance {
 
     #[tracing::instrument(skip_all)]
     async fn do_query(&self, query: &str, query_ctx: QueryContextRef) -> Vec<Result<Output>> {
+        if self.is_suspended() {
+            return vec![error::SuspendedSnafu {}.fail()];
+        }
+
         let query_interceptor_opt = self.plugins.get::<SqlQueryInterceptorRef<Error>>();
         let query_interceptor = query_interceptor_opt.as_ref();
         let query = match query_interceptor.pre_parsing(query, query_ctx.clone()) {
@@ -580,6 +593,8 @@ impl SqlQueryHandler for Instance {
         plan: LogicalPlan,
         query_ctx: QueryContextRef,
     ) -> Result<Output> {
+        ensure!(!self.is_suspended(), error::SuspendedSnafu);
+
         if should_capture_statement(stmt.as_ref()) {
             // It's safe to unwrap here because we've already checked the type.
             let stmt = stmt.unwrap();
@@ -641,6 +656,10 @@ impl SqlQueryHandler for Instance {
         query: &PromQuery,
         query_ctx: QueryContextRef,
     ) -> Vec<Result<Output>> {
+        if self.is_suspended() {
+            return vec![error::SuspendedSnafu {}.fail()];
+        }
+
         // check will be done in prometheus handler's do_query
         let result = PrometheusHandler::do_query(self, query, query_ctx)
             .await
@@ -655,6 +674,8 @@ impl SqlQueryHandler for Instance {
         stmt: Statement,
         query_ctx: QueryContextRef,
     ) -> Result<Option<DescribeResult>> {
+        ensure!(!self.is_suspended(), error::SuspendedSnafu);
+
         if matches!(
             stmt,
             Statement::Insert(_) | Statement::Query(_) | Statement::Delete(_)
@@ -875,7 +896,7 @@ pub fn check_permission(
             validate_param(&stmt.table_name, query_ctx)?;
         }
         Statement::ShowCreateFlow(stmt) => {
-            validate_param(&stmt.flow_name, query_ctx)?;
+            validate_flow(&stmt.flow_name, query_ctx)?;
         }
         #[cfg(feature = "enterprise")]
         Statement::ShowCreateTrigger(stmt) => {
@@ -908,6 +929,12 @@ pub fn check_permission(
         // show charset and show collation won't be checked
         Statement::ShowCharset(_) | Statement::ShowCollation(_) => {}
 
+        Statement::Comment(comment) => match &comment.object {
+            CommentObject::Table(table) => validate_param(table, query_ctx)?,
+            CommentObject::Column { table, .. } => validate_param(table, query_ctx)?,
+            CommentObject::Flow(flow) => validate_flow(flow, query_ctx)?,
+        },
+
         Statement::Insert(insert) => {
             let name = insert.table_name().context(ParseSqlSnafu)?;
             validate_param(name, query_ctx)?;
@@ -993,6 +1020,27 @@ fn validate_param(name: &ObjectName, query_ctx: &QueryContextRef) -> Result<()>
         .context(SqlExecInterceptedSnafu)
 }
 
+fn validate_flow(name: &ObjectName, query_ctx: &QueryContextRef) -> Result<()> {
+    let catalog = match &name.0[..] {
+        [_flow] => query_ctx.current_catalog().to_string(),
+        [catalog, _flow] => catalog.to_string_unquoted(),
+        _ => {
+            return InvalidSqlSnafu {
+                err_msg: format!(
+                    "expect flow name to be <catalog>.<flow_name> or <flow_name>, actual: {name}",
+                ),
+            }
+            .fail();
+        }
+    };
+
+    let schema = query_ctx.current_schema();
+
+    validate_catalog_and_schema(&catalog, &schema, query_ctx)
+        .map_err(BoxedError::new)
+        .context(SqlExecInterceptedSnafu)
+}
+
 fn validate_database(name: &ObjectName, query_ctx: &QueryContextRef) -> Result<()> {
     let (catalog, schema) = match &name.0[..] {
         [schema] => (
@@ -1251,6 +1299,28 @@ mod tests {
 
         // test describe table
         let sql = "DESC TABLE {catalog}{schema}demo;";
-        replace_test(sql, plugins, &query_ctx);
+        replace_test(sql, plugins.clone(), &query_ctx);
+
+        let comment_flow_cases = [
+            ("COMMENT ON FLOW my_flow IS 'comment';", true),
+            ("COMMENT ON FLOW greptime.my_flow IS 'comment';", true),
+            ("COMMENT ON FLOW wrongcatalog.my_flow IS 'comment';", false),
+        ];
+        for (sql, is_ok) in comment_flow_cases {
+            let stmt = &parse_stmt(sql, &GreptimeDbDialect {}).unwrap()[0];
+            let result = check_permission(plugins.clone(), stmt, &query_ctx);
+            assert_eq!(result.is_ok(), is_ok);
+        }
+
+        let show_flow_cases = [
+            ("SHOW CREATE FLOW my_flow;", true),
+            ("SHOW CREATE FLOW greptime.my_flow;", true),
+            ("SHOW CREATE FLOW wrongcatalog.my_flow;", false),
+        ];
+        for (sql, is_ok) in show_flow_cases {
+            let stmt = &parse_stmt(sql, &GreptimeDbDialect {}).unwrap()[0];
+            let result = check_permission(plugins.clone(), stmt, &query_ctx);
+            assert_eq!(result.is_ok(), is_ok);
+        }
     }
 }

src/frontend/src/instance/builder.rs

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 use std::sync::Arc;
+use std::sync::atomic::AtomicBool;
 
 use cache::{TABLE_FLOWNODE_SET_CACHE_NAME, TABLE_ROUTE_CACHE_NAME};
 use catalog::CatalogManagerRef;
@@ -48,7 +49,6 @@ use crate::events::EventHandlerImpl;
 use crate::frontend::FrontendOptions;
 use crate::instance::Instance;
 use crate::instance::region_query::FrontendRegionQueryHandler;
-use crate::limiter::Limiter;
 
 /// The frontend [`Instance`] builder.
 pub struct FrontendBuilder {
@@ -87,6 +87,33 @@ impl FrontendBuilder {
         }
     }
 
+    #[cfg(test)]
+    pub(crate) fn new_test(
+        options: &FrontendOptions,
+        meta_client: meta_client::MetaClientRef,
+    ) -> Self {
+        let kv_backend = Arc::new(common_meta::kv_backend::memory::MemoryKvBackend::new());
+
+        let layered_cache_registry = Arc::new(
+            common_meta::cache::LayeredCacheRegistryBuilder::default()
+                .add_cache_registry(cache::build_fundamental_cache_registry(kv_backend.clone()))
+                .build(),
+        );
+
+        Self::new(
+            options.clone(),
+            kv_backend,
+            layered_cache_registry,
+            catalog::memory::MemoryCatalogManager::with_default_setup(),
+            Arc::new(client::client_manager::NodeClients::default()),
+            meta_client,
+            Arc::new(catalog::process_manager::ProcessManager::new(
+                "".to_string(),
+                None,
+            )),
+        )
+    }
+
     pub fn with_local_cache_invalidator(self, cache_invalidator: CacheInvalidatorRef) -> Self {
         Self {
             local_cache_invalidator: Some(cache_invalidator),
@@ -220,14 +247,6 @@ impl FrontendBuilder {
             self.options.event_recorder.ttl,
         ))));
 
-        // Create the limiter if the max_in_flight_write_bytes is set.
-        let limiter = self
-            .options
-            .max_in_flight_write_bytes
-            .map(|max_in_flight_write_bytes| {
-                Arc::new(Limiter::new(max_in_flight_write_bytes.as_bytes() as usize))
-            });
-
         Ok(Instance {
             catalog_manager: self.catalog_manager,
             pipeline_operator,
@@ -238,10 +257,10 @@ impl FrontendBuilder {
             deleter,
             table_metadata_manager: Arc::new(TableMetadataManager::new(kv_backend)),
             event_recorder: Some(event_recorder),
-            limiter,
             process_manager,
             otlp_metrics_table_legacy_cache: DashMap::new(),
             slow_query_options: self.options.slow_query.clone(),
+            suspend: Arc::new(AtomicBool::new(false)),
         })
     }
 }

src/frontend/src/instance/grpc.rs

@@ -71,12 +71,6 @@ impl GrpcQueryHandler for Instance {
             .check_permission(ctx.current_user(), PermissionReq::GrpcRequest(&request))
             .context(PermissionSnafu)?;
 
-        let _guard = if let Some(limiter) = &self.limiter {
-            Some(limiter.limit_request(&request).await?)
-        } else {
-            None
-        };
-
         let output = match request {
             Request::Inserts(requests) => self.handle_inserts(requests, ctx.clone()).await?,
             Request::RowInserts(requests) => {
@@ -234,6 +228,11 @@ impl GrpcQueryHandler for Instance {
                     DdlExpr::DropView(_) => {
                         todo!("implemented in the following PR")
                     }
+                    DdlExpr::CommentOn(expr) => {
+                        self.statement_executor
+                            .comment_by_expr(expr, ctx.clone())
+                            .await?
+                    }
                 }
             }
         };
@@ -296,22 +295,35 @@ impl GrpcQueryHandler for Instance {
         mut stream: servers::grpc::flight::PutRecordBatchRequestStream,
         ctx: QueryContextRef,
     ) -> Pin<Box<dyn Stream<Item = Result<DoPutResponse>> + Send>> {
-        // Resolve table once for the stream
         // Clone all necessary data to make it 'static
         let catalog_manager = self.catalog_manager().clone();
         let plugins = self.plugins.clone();
         let inserter = self.inserter.clone();
-        let table_name = stream.table_name().clone();
         let ctx = ctx.clone();
+        let mut table_ref: Option<TableRef> = None;
+        let mut table_checked = false;
 
         Box::pin(try_stream! {
+            // Process each request in the stream
+            while let Some(request_result) = stream.next().await {
+                let request = request_result.map_err(|e| {
+                    let error_msg = format!("Stream error: {:?}", e);
+                    IncompleteGrpcRequestSnafu { err_msg: error_msg }.build()
+                })?;
+
+                // Resolve table and check permissions on first RecordBatch (after schema is received)
+                if !table_checked {
+                    let table_name = &request.table_name;
+
                     plugins
                         .get::<PermissionCheckerRef>()
                         .as_ref()
                         .check_permission(ctx.current_user(), PermissionReq::BulkInsert)
                         .context(PermissionSnafu)?;
-            // Cache for resolved table reference - resolve once and reuse
-            let table_ref = catalog_manager
+
+                    // Resolve table reference
+                    table_ref = Some(
+                        catalog_manager
                             .table(
                                 &table_name.catalog_name,
                                 &table_name.schema_name,
@@ -322,25 +334,22 @@ impl GrpcQueryHandler for Instance {
                             .context(CatalogSnafu)?
                             .with_context(|| TableNotFoundSnafu {
                                 table_name: table_name.to_string(),
-                })?;
+                            })?,
+                    );
 
-            // Check permissions once for the stream
+                    // Check permissions for the table
                     let interceptor_ref = plugins.get::<GrpcQueryInterceptorRef<Error>>();
                     let interceptor = interceptor_ref.as_ref();
-            interceptor.pre_bulk_insert(table_ref.clone(), ctx.clone())?;
+                    interceptor.pre_bulk_insert(table_ref.clone().unwrap(), ctx.clone())?;
 
-            // Process each request in the stream
-            while let Some(request_result) = stream.next().await {
-                let request = request_result.map_err(|e| {
-                    let error_msg = format!("Stream error: {:?}", e);
-                    IncompleteGrpcRequestSnafu { err_msg: error_msg }.build()
-                })?;
+                    table_checked = true;
+                }
 
                 let request_id = request.request_id;
                 let start = Instant::now();
                 let rows = inserter
                     .handle_bulk_insert(
-                        table_ref.clone(),
+                        table_ref.clone().unwrap(),
                         request.flight_data,
                         request.record_batch,
                         request.schema_bytes,
@@ -399,6 +408,9 @@ fn fill_catalog_and_schema_from_context(ddl_expr: &mut DdlExpr, ctx: &QueryConte
         Expr::DropView(expr) => {
             check_and_fill!(expr);
         }
+        Expr::CommentOn(expr) => {
+            check_and_fill!(expr);
+        }
     }
 }
 

src/frontend/src/instance/influxdb.rs

@@ -22,7 +22,7 @@ use common_error::ext::BoxedError;
 use common_time::Timestamp;
 use common_time::timestamp::TimeUnit;
 use servers::error::{
-    AuthSnafu, CatalogSnafu, Error, OtherSnafu, TimestampOverflowSnafu, UnexpectedResultSnafu,
+    AuthSnafu, CatalogSnafu, Error, TimestampOverflowSnafu, UnexpectedResultSnafu,
 };
 use servers::influxdb::InfluxdbRequest;
 use servers::interceptor::{LineProtocolInterceptor, LineProtocolInterceptorRef};
@@ -59,18 +59,6 @@ impl InfluxdbLineProtocolHandler for Instance {
             .post_lines_conversion(requests, ctx.clone())
             .await?;
 
-        let _guard = if let Some(limiter) = &self.limiter {
-            Some(
-                limiter
-                    .limit_row_inserts(&requests)
-                    .await
-                    .map_err(BoxedError::new)
-                    .context(OtherSnafu)?,
-            )
-        } else {
-            None
-        };
-
         self.handle_influx_row_inserts(requests, ctx)
             .await
             .map_err(BoxedError::new)

src/frontend/src/instance/jaeger.rs

@@ -65,8 +65,7 @@ impl JaegerQueryHandler for Instance {
         // It's equivalent to `SELECT DISTINCT(service_name) FROM {db}.{trace_table}`.
         Ok(query_trace_table(
             ctx,
-            self.catalog_manager(),
-            self.query_engine(),
+            self,
             vec![SelectExpr::from(col(SERVICE_NAME_COLUMN))],
             vec![],
             vec![],
@@ -107,8 +106,7 @@ impl JaegerQueryHandler for Instance {
         // ```.
         Ok(query_trace_table(
             ctx,
-            self.catalog_manager(),
-            self.query_engine(),
+            self,
             vec![
                 SelectExpr::from(col(SPAN_NAME_COLUMN)),
                 SelectExpr::from(col(SPAN_KIND_COLUMN)),
@@ -160,8 +158,7 @@ impl JaegerQueryHandler for Instance {
 
         Ok(query_trace_table(
             ctx,
-            self.catalog_manager(),
-            self.query_engine(),
+            self,
             selects,
             filters,
             vec![col(TIMESTAMP_COLUMN).sort(false, false)], // Sort by timestamp in descending order.
@@ -220,8 +217,7 @@ impl JaegerQueryHandler for Instance {
         // ```.
         let output = query_trace_table(
             ctx.clone(),
-            self.catalog_manager(),
-            self.query_engine(),
+            self,
             vec![wildcard()],
             filters,
             vec![],
@@ -285,8 +281,7 @@ impl JaegerQueryHandler for Instance {
                 // query all spans
                 Ok(query_trace_table(
                     ctx,
-                    self.catalog_manager(),
-                    self.query_engine(),
+                    self,
                     vec![wildcard()],
                     filters,
                     vec![col(TIMESTAMP_COLUMN).sort(false, false)], // Sort by timestamp in descending order.
@@ -303,8 +298,7 @@ impl JaegerQueryHandler for Instance {
 #[allow(clippy::too_many_arguments)]
 async fn query_trace_table(
     ctx: QueryContextRef,
-    catalog_manager: &CatalogManagerRef,
-    query_engine: &QueryEngineRef,
+    instance: &Instance,
     selects: Vec<SelectExpr>,
     filters: Vec<Expr>,
     sorts: Vec<SortExpr>,
@@ -334,7 +328,8 @@ async fn query_trace_table(
         }
     };
 
-    let table = catalog_manager
+    let table = instance
+        .catalog_manager()
         .table(
             ctx.current_catalog(),
             &ctx.current_schema(),
@@ -367,7 +362,7 @@ async fn query_trace_table(
         .map(|s| format!("\"{}\"", s))
         .collect::<HashSet<String>>();
 
-    let df_context = create_df_context(query_engine)?;
+    let df_context = create_df_context(instance.query_engine())?;
 
     let dataframe = df_context
         .read_table(Arc::new(DfTableProviderAdapter::new(table)))

src/frontend/src/instance/log_handler.rs

@@ -23,8 +23,7 @@ use datatypes::timestamp::TimestampNanosecond;
 use pipeline::pipeline_operator::PipelineOperator;
 use pipeline::{Pipeline, PipelineInfo, PipelineVersion};
 use servers::error::{
-    AuthSnafu, Error as ServerError, ExecuteGrpcRequestSnafu, OtherSnafu, PipelineSnafu,
-    Result as ServerResult,
+    AuthSnafu, Error as ServerError, ExecuteGrpcRequestSnafu, PipelineSnafu, Result as ServerResult,
 };
 use servers::interceptor::{LogIngestInterceptor, LogIngestInterceptorRef};
 use servers::query_handler::PipelineHandler;
@@ -124,18 +123,6 @@ impl Instance {
         log: RowInsertRequests,
         ctx: QueryContextRef,
     ) -> ServerResult<Output> {
-        let _guard = if let Some(limiter) = &self.limiter {
-            Some(
-                limiter
-                    .limit_row_inserts(&log)
-                    .await
-                    .map_err(BoxedError::new)
-                    .context(OtherSnafu)?,
-            )
-        } else {
-            None
-        };
-
         self.inserter
             .handle_log_inserts(log, ctx, self.statement_executor.as_ref())
             .await
@@ -148,18 +135,6 @@ impl Instance {
         rows: RowInsertRequests,
         ctx: QueryContextRef,
     ) -> ServerResult<Output> {
-        let _guard = if let Some(limiter) = &self.limiter {
-            Some(
-                limiter
-                    .limit_row_inserts(&rows)
-                    .await
-                    .map_err(BoxedError::new)
-                    .context(OtherSnafu)?,
-            )
-        } else {
-            None
-        };
-
         self.inserter
             .handle_trace_inserts(rows, ctx, self.statement_executor.as_ref())
             .await

src/frontend/src/instance/opentsdb.rs

@@ -16,7 +16,7 @@ use async_trait::async_trait;
 use auth::{PermissionChecker, PermissionCheckerRef, PermissionReq};
 use common_error::ext::BoxedError;
 use common_telemetry::tracing;
-use servers::error::{self as server_error, AuthSnafu, ExecuteGrpcQuerySnafu, OtherSnafu};
+use servers::error::{self as server_error, AuthSnafu, ExecuteGrpcQuerySnafu};
 use servers::opentsdb::codec::DataPoint;
 use servers::opentsdb::data_point_to_grpc_row_insert_requests;
 use servers::query_handler::OpentsdbProtocolHandler;
@@ -41,18 +41,6 @@ impl OpentsdbProtocolHandler for Instance {
 
         let (requests, _) = data_point_to_grpc_row_insert_requests(data_points)?;
 
-        let _guard = if let Some(limiter) = &self.limiter {
-            Some(
-                limiter
-                    .limit_row_inserts(&requests)
-                    .await
-                    .map_err(BoxedError::new)
-                    .context(OtherSnafu)?,
-            )
-        } else {
-            None
-        };
-
         // OpenTSDB is single value.
         let output = self
             .handle_row_inserts(requests, ctx, true, true)

src/frontend/src/instance/otlp.rs

@@ -24,7 +24,7 @@ use opentelemetry_proto::tonic::collector::logs::v1::ExportLogsServiceRequest;
 use opentelemetry_proto::tonic::collector::trace::v1::ExportTraceServiceRequest;
 use otel_arrow_rust::proto::opentelemetry::collector::metrics::v1::ExportMetricsServiceRequest;
 use pipeline::{GreptimePipelineParams, PipelineWay};
-use servers::error::{self, AuthSnafu, OtherSnafu, Result as ServerResult};
+use servers::error::{self, AuthSnafu, Result as ServerResult};
 use servers::http::prom_store::PHYSICAL_TABLE_PARAM;
 use servers::interceptor::{OpenTelemetryProtocolInterceptor, OpenTelemetryProtocolInterceptorRef};
 use servers::otlp;
@@ -83,18 +83,6 @@ impl OpenTelemetryProtocolHandler for Instance {
             ctx
         };
 
-        let _guard = if let Some(limiter) = &self.limiter {
-            Some(
-                limiter
-                    .limit_row_inserts(&requests)
-                    .await
-                    .map_err(BoxedError::new)
-                    .context(OtherSnafu)?,
-            )
-        } else {
-            None
-        };
-
         // If the user uses the legacy path, it is by default without metric engine.
         if metric_ctx.is_legacy || !metric_ctx.with_metric_engine {
             self.handle_row_inserts(requests, ctx, false, false)
@@ -191,18 +179,6 @@ impl OpenTelemetryProtocolHandler for Instance {
         )
         .await?;
 
-        let _guard = if let Some(limiter) = &self.limiter {
-            Some(
-                limiter
-                    .limit_ctx_req(&opt_req)
-                    .await
-                    .map_err(BoxedError::new)
-                    .context(OtherSnafu)?,
-            )
-        } else {
-            None
-        };
-
         let mut outputs = vec![];
 
         for (temp_ctx, requests) in opt_req.as_req_iter(ctx) {

src/frontend/src/instance/prom_store.rs

@@ -175,18 +175,6 @@ impl PromStoreProtocolHandler for Instance {
             .get::<PromStoreProtocolInterceptorRef<servers::error::Error>>();
         interceptor_ref.pre_write(&request, ctx.clone())?;
 
-        let _guard = if let Some(limiter) = &self.limiter {
-            Some(
-                limiter
-                    .limit_row_inserts(&request)
-                    .await
-                    .map_err(BoxedError::new)
-                    .context(error::OtherSnafu)?,
-            )
-        } else {
-            None
-        };
-
         let output = if with_metric_engine {
             let physical_table = ctx
                 .extension(PHYSICAL_TABLE_PARAM)

src/frontend/src/lib.rs

@@ -19,7 +19,6 @@ pub mod events;
 pub mod frontend;
 pub mod heartbeat;
 pub mod instance;
-pub(crate) mod limiter;
 pub(crate) mod metrics;
 pub mod server;
 pub mod service_config;