* feat: add close-first soft-drop table flow Soft-drop now tombstones table metadata and closes datanode regions instead of issuing physical drop requests, while preserving hard-drop cleanup semantics and blocking conflicting drops of recreated table names. Files: - `src/common/meta/src/ddl.rs` - `src/common/meta/src/ddl/drop_table.rs` - `src/common/meta/src/ddl/drop_table/executor.rs` - `src/common/meta/src/error.rs` - `src/common/meta/src/ddl_manager.rs` - `src/meta-srv/src/metasrv/builder.rs` - `src/cmd/src/standalone.rs` - `src/common/meta/src/test_util.rs` - `src/meta-srv/src/procedure/utils.rs` - `tests-integration/src/standalone.rs` - `src/common/meta/src/ddl/tests/drop_table.rs` Signed-off-by: Lei, HUANG <mrsatangel@gmail.com> * feat: add undrop and purge table procedures Add soft-drop recovery and cleanup procedures, wire their DDL task handling, and update \`greptime-proto\` so the new tasks can round-trip through protobuf. Files: - \`Cargo.toml\` - \`Cargo.lock\` - \`src/common/meta/src/ddl.rs\` - \`src/common/meta/src/ddl/undrop_table.rs\` - \`src/common/meta/src/ddl/purge_dropped_table.rs\` - \`src/common/meta/src/ddl_manager.rs\` - \`src/common/meta/src/rpc/ddl.rs\` - \`src/common/meta/src/key.rs\` - \`src/common/meta/src/ddl/tests/drop_table.rs\` - \`src/mito2/src/engine/open_test.rs\` Signed-off-by: Lei, HUANG <mrsatangel@gmail.com> * fix: reopen soft-dropped regions before purge Signed-off-by: Lei, HUANG <mrsatangel@gmail.com> * feat: disable soft-drop operations for metric logical tables Prevent soft-dropping, undropping, and purging of metric engine logical tables by explicitly returning unsupported errors. This introduces `is_metric_engine_logical_table` to identify metric logical tables and adds corresponding test cases. Files: - `src/common/meta/src/ddl/drop_table/metadata.rs` - `src/common/meta/src/ddl/purge_dropped_table.rs` - `src/common/meta/src/ddl/tests/drop_table.rs` - `src/common/meta/src/ddl/undrop_table.rs` - `src/common/meta/src/ddl/utils.rs` Signed-off-by: Lei, HUANG <mrsatangel@gmail.com> * fix: sync failure detectors during soft-drop lifecycle Keep region failure detector state aligned as soft-dropped tables close, reopen, and purge regions so stale detectors do not trigger failover for unavailable or deleted regions. Files: - \`src/common/meta/src/ddl.rs\` - \`src/common/meta/src/ddl/drop_table.rs\` - \`src/common/meta/src/ddl/undrop_table.rs\` - \`src/common/meta/src/ddl/purge_dropped_table.rs\` - \`src/common/meta/src/ddl/tests/drop_table.rs\` Signed-off-by: Lei, HUANG <mrsatangel@gmail.com> * refactor: simplify soft-drop table tests Consolidate redundant soft-drop lifecycle assertions into existing end-to-end tests and share dropped-table metadata setup to keep the branch coverage focused. Files: - `src/common/meta/src/ddl/tests/drop_table.rs` - `src/common/meta/src/key.rs` - `src/mito2/src/engine/open_test.rs` Signed-off-by: Lei, HUANG <mrsatangel@gmail.com> * fix: reopen follower regions during undrop Reopen all replicas when restoring dropped physical tables so recovered replicated tables do not leave follower regions closed. Files: - `src/common/meta/src/ddl/undrop_table.rs` - `src/common/meta/src/ddl/tests/drop_table.rs` Signed-off-by: Lei, HUANG <mrsatangel@gmail.com> * feat: use dropped table ddl expr protos Update greptime-proto and adapt dropped table DDL task conversions to the shared expression wrappers required by the proto API. Files: - `Cargo.toml` - `Cargo.lock` - `src/api/src/helper.rs` - `src/common/meta/src/ddl/drop_table/executor.rs` - `src/common/meta/src/rpc/ddl.rs` Signed-off-by: Lei, HUANG <mrsatangel@gmail.com> * revert: use inline dropped table task protos Point GreptimeDB at the proto revision that restores direct dropped table task fields and remove wrapper-expression conversion code. Files: - `Cargo.toml` - `Cargo.lock` - `src/api/src/helper.rs` - `src/common/meta/src/rpc/ddl.rs` Signed-off-by: Lei, HUANG <mrsatangel@gmail.com> * feat: various soft-drop improvements - Bump `greptime-proto` dependency revision (`Cargo.toml`, `Cargo.lock`) - Pass `region_wal_options` directly without pre-serialization in undrop flow (`src/common/meta/src/ddl/undrop_table.rs`, `src/common/meta/src/key.rs`) - Remove unused `RegionNumber` import (`src/common/meta/src/ddl/utils.rs`) - Add `reset_failure_detectors` to test mock (`src/common/meta/src/ddl/tests/drop_table.rs`) - Add JSON roundtrip tests for `UndropTableTask` and `PurgeDroppedTableTask` (`src/common/meta/src/rpc/ddl.rs`) Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> * feat: validate table name match in undrop procedure Add a guard in `UndropTableProcedure::on_prepare()` to check that the dropped table name matches the undrop task name, returning `TableNotFound` on mismatch. This prevents undropping a table by a different name when only the table ID is known. - `src/common/meta/src/ddl/undrop_table.rs` — add table-name validation - `src/common/meta/src/ddl/tests/drop_table.rs` — add test for name mismatch Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> * refactor: simplify UndropTableTask to use table_id only Remove catalog, schema, and table name fields from `UndropTableTask` since the table name can be derived from the dropped table metadata in the procedure itself. This eliminates redundant fields and the associated name-validation test. Simplify locking in `UndropTableProcedure` to only use `TableLock`. Update `greptime-proto` dependency revision. - `Cargo.toml`, `Cargo.lock` - `src/common/meta/src/rpc/ddl.rs` - `src/common/meta/src/ddl/undrop_table.rs` - `src/common/meta/src/ddl/tests/drop_table.rs` Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> * feat: detect table name conflict during tombstone restore in undrop - Added `require_dest_not_exists` parameter to tombstone `move_values` to check destination key existence during restore - Added `TombstoneTargetAlreadyExists` error variant - Map tombstone conflict to `TableAlreadyExists` in undrop procedure - Added test for undrop failing when live name created after prepare Files: - `src/common/meta/src/ddl/tests/drop_table.rs` - `src/common/meta/src/ddl/undrop_table.rs` - `src/common/meta/src/error.rs` - `src/common/meta/src/key/tombstone.rs` Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> * feat: make PurgeDroppedTableTask table_id-only Streamline the purge-dropped-table flow by requiring a table_id instead of allowing name-based fallback. - Refactored `PurgeDroppedTableTask` to hold only `table_id` in `src/common/meta/src/rpc/ddl.rs` - Simplified purge procedure in `src/common/meta/src/ddl/purge_dropped_table.rs` - Adapted tests in `src/common/meta/src/ddl/tests/drop_table.rs` - Bumped `greptime-proto` dependency Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> * fix(tombstone): chunk values by per-key txn ops instead of fixed divisor Replaced the fixed `max_txn_ops() / 2` chunk size with operation-aware constants (`MOVE_VALUE_TXN_OPS_PER_KEY=4`, `RESTORE_VALUE_TXN_OPS_PER_KEY=6`) to correctly account for per-key transaction operations. Added `TxnOpLimitKvBackend` test helper and two new tests (`test_restore_chunks_by_total_txn_ops_limit`, `test_create_chunks_by_total_txn_ops_limit`) verifying chunking under tight txn op limits. Affected file: - `src/common/meta/src/key/tombstone.rs` — chunk size fix, `TxnOpLimitKvBackend` helper, two new tests Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> * feat(soft-drop): deregister failure detectors and handle replayed open-regions during purge - `src/common/meta/src/ddl/drop_table.rs`: deregister failure detectors before transitioning to DeleteTombstone state - `src/common/meta/src/ddl/undrop_table.rs`: refactor `open_regions` into `open_regions_inner` with an `ignore_region_not_found` flag; expose `open_regions_ignore_region_not_found` for purge replayer - `src/common/meta/src/ddl/purge_dropped_table.rs`: use `open_regions_ignore_region_not_found` in replayed purge procedures - `src/common/meta/src/ddl/tests/drop_table.rs`: add tests for undrop idempotency and purge replay tolerance of dropped regions Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> * chore: fix clippy Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> * fix(soft-drop): open regions before restoring undrop metadata Restore undropped table metadata only after physical regions have been reopened, keeping the table hidden while regions are still closed. Preserve the live-name conflict check before opening regions and cover the ordering with a regression test. Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> * fix(tombstone): fail fast on invalid txn op budget Fail before issuing `TombstoneManager` transactions when the configured `max_txn_ops` cannot fit one key. Add coverage for undersized restore budgets in `src/common/meta/src/key/tombstone.rs`. Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> * chore: bump greptime-proto to main branch commit Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> --------- Signed-off-by: Lei, HUANG <mrsatangel@gmail.com> Signed-off-by: Lei, HUANG <ratuthomm@gmail.com> Signed-off-by: Lei, HUANG <ratuthomm@gmail.com>
One database for metrics, logs, and traces
replacing Prometheus, Loki, and Elasticsearch
The unified OpenTelemetry backend — with SQL + PromQL on object storage.
- Introduction
- Overview
- Features
- How GreptimeDB Compares
- Architecture
- Try GreptimeDB
- Getting Started
- Build From Source
- Tools & Extensions
- Project Status
- Community
- License
- Commercial Support
- Contributing
- Acknowledgement
Introduction
GreptimeDB is an open-source observability database built for Observability 2.0 — treating metrics, logs, and traces as one unified data model (wide events) instead of three separate pillars.
Use it as the single OpenTelemetry backend — replacing Prometheus, Loki, and Elasticsearch with one database built on object storage. Query with SQL and PromQL, scale without pain, cut costs up to 50×.
Overview
A quick overview of what GreptimeDB ingests, how it connects to other systems, and what its distributed engine lets you do.
Features
| Feature | Description |
|---|---|
| Observability 2.0 native | Logs, metrics, and traces in one engine with SQL + PromQL. Native OpenTelemetry, Prometheus remote write, and Jaeger. Migrate one signal at a time, or use as a single backend. |
| Elastic compute-storage separation | Scale reads independently with horizontal replicas. Serve high-concurrency workloads from dashboards, alerting, and AI agents — without resharding or data migration. |
| Sub-second on PB–EB-scale data | Columnar engine with fulltext, inverted, and skipping indexes. Written in Rust. Designed for high-concurrency point queries, not just analytical scans. |
| 50× lower cost | Object storage (S3, GCS, Azure Blob) as primary storage, with a tiered cache (memory + local disk) to keep writes and queries fast. |
Perfect for:
- Replacing Prometheus + Loki + Elasticsearch with a single observability backend
- Scaling past Prometheus — high cardinality, long-term storage, no Thanos/Mimir overhead
- AI/agent workloads — store GenAI telemetry (OTel GenAI conventions), and serve high-concurrency reads from SRE/developer agents via horizontal read replicas
- Cutting observability costs with object storage (up to 50× savings on traces, 30% on logs)
- Edge-to-cloud observability with unified APIs on resource-constrained devices
Why Observability 2.0? Three separate databases for metrics, logs, and traces means three storage layers, three query languages, and three sets of dashboards. GreptimeDB stores all three as timestamped wide events in one columnar engine — JOIN across signals in SQL, run one stack instead of three, and ingest AI agent telemetry the same way. Read more: Observability 2.0 and the Database for It.
Learn more in Why GreptimeDB.
How GreptimeDB Compares
| Capability | GreptimeDB | Prometheus / Thanos / Mimir | Grafana Loki | Elasticsearch |
|---|---|---|---|---|
| Data types | Metrics, logs, traces | Metrics only | Logs only | Logs, traces |
| Query language | SQL + PromQL | PromQL | LogQL | Query DSL |
| Storage | Native object storage (S3, etc.) | Local disk + object storage (Thanos/Mimir) | Object storage (chunks) | Local disk |
| Scaling | Compute-storage separation, stateless nodes | Federation / Thanos / Mimir — multi-component, ops heavy | Stateless + object storage | Shard-based, ops heavy |
| Cost efficiency | Up to 50× lower storage cost | High at scale | Moderate | High (inverted index overhead) |
| OpenTelemetry | Native (metrics + logs + traces) | Partial (metrics only) | Partial (logs only) | Via instrumentation |
Benchmarks:
Architecture
GreptimeDB can run in two modes:
- Standalone — single binary for development and small deployments.
- Distributed — four components, each independently scalable:
- Frontend — protocol entry (OTel, Prometheus, MySQL/PostgreSQL, gRPC, ingestion APIs for Elasticsearch/InfluxDB/Loki) and the distributed query engine. Stateless, scales horizontally.
- Datanode — region engine with WAL, memtable, SST, cache, compaction, and indexes. Persists data to object storage. Elastic.
- Metasrv — metadata, routing, repartitioning, autopilot, and security. Backed by a pluggable KV layer (etcd or RDS).
- Flownode (optional) — continuous flow computation (streaming and materialized views).
For deeper coverage, see the architecture doc or DeepWiki.
Try GreptimeDB
For AI agents — paste this prompt into your agent:
Read https://docs.greptime.com/SKILL.md and follow the instructions
to deploy, configure, ingest, and query GreptimeDB.
docker run -p 127.0.0.1:4000-4003:4000-4003 \
-v "$(pwd)/greptimedb_data:/greptimedb_data" \
--name greptime --rm \
greptime/greptimedb:latest standalone start \
--http-addr 0.0.0.0:4000 \
--rpc-bind-addr 0.0.0.0:4001 \
--mysql-addr 0.0.0.0:4002 \
--postgres-addr 0.0.0.0:4003
Dashboard: http://localhost:4000/dashboard
Read more in the full Install Guide.
Troubleshooting:
- Cannot connect to the database? Ensure that ports
4000,4001,4002, and4003are not blocked by a firewall or used by other services. - Failed to start? Check the container logs with
docker logs greptimefor further details.
Getting Started
Build From Source
Prerequisites:
- Rust toolchain — nightly, pinned by
rust-toolchain.toml - Protobuf compiler (>= 3.15)
- C/C++ building essentials:
gcc/g++/autoconfand the glibc dev package (libc6-devon Ubuntu,glibc-develon Fedora) - Python toolchain (optional, only for some test scripts)
Build and run:
make # build greptime binary
cargo run -- standalone start # start in standalone mode
Common dev commands:
make fmt # format Rust code
make clippy # lint (fails on warnings)
make test # unit + integration tests (uses cargo-nextest)
make sqlness-test # SQL regression tests
See the Contribution Guidelines for the full developer workflow.
Tools & Extensions
- Kubernetes: GreptimeDB Operator
- Helm Charts: Greptime Helm Charts
- Dashboard: Web UI
- gRPC Ingester: Go, Java, C++, Erlang, Rust, .NET
- Grafana Data Source: GreptimeDB Grafana data source plugin
- Grafana Dashboard: Official Dashboard for monitoring
Project Status
GreptimeDB is at v1.0 GA with stable APIs and regular releases. It runs in production at scale — OceanBase Cloud operates 80+ GreptimeDB clusters managing 300 TB of logs, cutting log storage cost by 60% after migrating from Grafana Loki. See more in case studies.
Read the v1.0 highlights and 2026 roadmap, or browse the version reference.
If GreptimeDB is useful to you, please star the repo.
Community
We invite you to engage and contribute!
License
GreptimeDB is an open-core project. Its core is licensed under the Apache License 2.0.
A small set of peripheral, enterprise-only features are gated behind the
enterprise Cargo feature (not built by default) and are governed by the
separate GreptimeDB Enterprise License. Source files under
that license carry an explicit Enterprise License header.
Commercial Support
Running GreptimeDB in your organization? We offer enterprise add-ons, services, training, and consulting. Contact us for details.
Contributing
- Read our Contribution Guidelines.
- Explore Internal Concepts and DeepWiki.
- Pick up a good first issue and join the #contributors Slack channel.
Acknowledgement
Special thanks to all contributors! See AUTHOR.md.
- Uses Apache Arrow™ (memory model)
- Apache Parquet™ (file storage)
- Apache DataFusion™ (query engine)
- Apache OpenDAL™ (data access abstraction)
All trademarks, logos, and brand names referenced in this README and in the Overview diagram are the property of their respective owners. Their use is for identification purposes only and does not imply endorsement or affiliation.
