# Configurations

- [Configurations](#configurations)
  - [Standalone Mode](#standalone-mode)
  - [Distributed Mode](#distributed-mode)
    - [Frontend](#frontend)
    - [Metasrv](#metasrv)
    - [Datanode](#datanode)
    - [Flownode](#flownode)

## Standalone Mode

| Key | Type | Default | Descriptions |
| --- | -----| ------- | ----------- |
| `mode` | String | `standalone` | The running mode of the datanode. It can be `standalone` or `distributed`. |
| `default_timezone` | String | Unset | The default timezone of the server. |
| `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. |
| `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. |
| `http` | -- | -- | The HTTP server options. |
| `http.addr` | String | `127.0.0.1:4000` | The address to bind the HTTP server. |
| `http.timeout` | String | `30s` | 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. |
| `grpc` | -- | -- | The gRPC server options. |
| `grpc.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.tls` | -- | -- | gRPC server TLS options, see `mysql.tls` section. |
| `grpc.tls.mode` | String | `disable` | TLS mode. |
| `grpc.tls.cert_path` | String | Unset | Certificate file path. |
| `grpc.tls.key_path` | String | Unset | Private key file path. |
| `grpc.tls.watch` | Bool | `false` | Watch for Certificate and key file change and auto reload.<br/>For now, gRPC tls config does not support auto reload. |
| `mysql` | -- | -- | MySQL server options. |
| `mysql.enable` | Bool | `true` | Whether to enable. |
| `mysql.addr` | String | `127.0.0.1:4002` | The addr to bind the MySQL server. |
| `mysql.runtime_size` | Integer | `2` | The number of server worker threads. |
| `mysql.tls` | -- | -- | -- |
| `mysql.tls.mode` | String | `disable` | TLS mode, refer to https://www.postgresql.org/docs/current/libpq-ssl.html<br/>- `disable` (default value)<br/>- `prefer`<br/>- `require`<br/>- `verify-ca`<br/>- `verify-full` |
| `mysql.tls.cert_path` | String | Unset | Certificate file path. |
| `mysql.tls.key_path` | String | Unset | Private key file path. |
| `mysql.tls.watch` | Bool | `false` | Watch for Certificate and key file change and auto reload |
| `postgres` | -- | -- | PostgresSQL server options. |
| `postgres.enable` | Bool | `true` | Whether to enable |
| `postgres.addr` | String | `127.0.0.1:4003` | The addr to bind the PostgresSQL server. |
| `postgres.runtime_size` | Integer | `2` | The number of server worker threads. |
| `postgres.tls` | -- | -- | PostgresSQL server TLS options, see `mysql.tls` section. |
| `postgres.tls.mode` | String | `disable` | TLS mode. |
| `postgres.tls.cert_path` | String | Unset | Certificate file path. |
| `postgres.tls.key_path` | String | Unset | Private key file path. |
| `postgres.tls.watch` | Bool | `false` | Watch for Certificate and key file change and auto reload |
| `opentsdb` | -- | -- | OpenTSDB protocol options. |
| `opentsdb.enable` | Bool | `true` | Whether to enable OpenTSDB put in HTTP API. |
| `influxdb` | -- | -- | InfluxDB protocol options. |
| `influxdb.enable` | Bool | `true` | Whether to enable InfluxDB protocol in HTTP API. |
| `prom_store` | -- | -- | Prometheus remote storage options |
| `prom_store.enable` | Bool | `true` | Whether to enable Prometheus remote write and read in HTTP API. |
| `prom_store.with_metric_engine` | Bool | `true` | Whether to store the data from Prometheus remote write in metric engine. |
| `wal` | -- | -- | The WAL options. |
| `wal.provider` | String | `raft_engine` | The provider of the WAL.<br/>- `raft_engine`: the wal is stored in the local file system by raft-engine.<br/>- `kafka`: it's remote wal that data is stored in Kafka. |
| `wal.dir` | String | Unset | The directory to store the WAL files.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.file_size` | String | `128MB` | The size of the WAL segment file.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.purge_threshold` | String | `1GB` | The threshold of the WAL size to trigger a flush.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.purge_interval` | String | `1m` | The interval to trigger a flush.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.read_batch_size` | Integer | `128` | The read batch size.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.sync_write` | Bool | `false` | Whether to use sync write.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.enable_log_recycle` | Bool | `true` | Whether to reuse logically truncated log files.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.prefill_log_files` | Bool | `false` | Whether to pre-create log files on start up.<br/>**It's only used when the provider is `raft_engine`**. |
| `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.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`**. |
| `wal.topic_name_prefix` | String | `greptimedb_wal_topic` | A Kafka topic is constructed by concatenating `topic_name_prefix` and `topic_id`.<br/>i.g., greptimedb_wal_topic_0, greptimedb_wal_topic_1.<br/>**It's only used when the provider is `kafka`**. |
| `wal.replication_factor` | Integer | `1` | Expected number of replicas of each partition.<br/>**It's only used when the provider is `kafka`**. |
| `wal.create_topic_timeout` | String | `30s` | Above which a topic creation operation will be cancelled.<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.backoff_init` | String | `500ms` | The initial backoff delay.<br/>**It's only used when the provider is `kafka`**. |
| `wal.backoff_max` | String | `10s` | The maximum backoff delay.<br/>**It's only used when the provider is `kafka`**. |
| `wal.backoff_base` | Integer | `2` | The exponential backoff rate, i.e. next backoff = base * current backoff.<br/>**It's only used when the provider is `kafka`**. |
| `wal.backoff_deadline` | String | `5mins` | The deadline of retries.<br/>**It's only used when the provider is `kafka`**. |
| `wal.overwrite_entry_start_id` | Bool | `false` | Ignore missing entries during read WAL.<br/>**It's only used when the provider is `kafka`**.<br/><br/>This option ensures that when Kafka messages are deleted, the system<br/>can still successfully replay memtable data without throwing an<br/>out-of-range error.<br/>However, enabling this option might lead to unexpected data loss,<br/>as the system will skip over missing entries instead of treating<br/>them as critical errors. |
| `metadata_store` | -- | -- | Metadata storage options. |
| `metadata_store.file_size` | String | `256MB` | Kv file size in bytes. |
| `metadata_store.purge_threshold` | String | `4GB` | Kv purge threshold. |
| `procedure` | -- | -- | Procedure storage options. |
| `procedure.max_retry_times` | Integer | `3` | Procedure max retry time. |
| `procedure.retry_delay` | String | `500ms` | Initial retry delay of procedures, increases exponentially |
| `flow` | -- | -- | flow engine options. |
| `flow.num_workers` | Integer | `0` | The number of flow worker in flownode.<br/>Not setting(or set to 0) this value will use the number of CPU cores divided by 2. |
| `storage` | -- | -- | The data storage options. |
| `storage.data_home` | String | `/tmp/greptimedb/` | 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.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`**. |
| `storage.secret_access_key` | String | Unset | The secret access key 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`**. |
| `storage.access_key_secret` | String | Unset | The secret access key of the aliyun account.<br/>**It's only used when the storage type is `Oss`**. |
| `storage.account_name` | String | Unset | The account key of the azure account.<br/>**It's only used when the storage type is `Azblob`**. |
| `storage.account_key` | String | Unset | The account key of the azure account.<br/>**It's only used when the storage type is `Azblob`**. |
| `storage.scope` | String | Unset | The scope of the google cloud storage.<br/>**It's only used when the storage type is `Gcs`**. |
| `storage.credential_path` | String | Unset | The credential path of the google cloud storage.<br/>**It's only used when the storage type is `Gcs`**. |
| `storage.credential` | String | Unset | The credential of the google cloud storage.<br/>**It's only used when the storage type is `Gcs`**. |
| `storage.container` | String | Unset | The container of the azure account.<br/>**It's only used when the storage type is `Azblob`**. |
| `storage.sas_token` | String | Unset | The sas token of the azure account.<br/>**It's only used when the storage type is `Azblob`**. |
| `storage.endpoint` | String | Unset | The endpoint of the S3 service.<br/>**It's only used when the storage type is `S3`, `Oss`, `Gcs` and `Azblob`**. |
| `storage.region` | String | Unset | The region of the S3 service.<br/>**It's only used when the storage type is `S3`, `Oss`, `Gcs` and `Azblob`**. |
| `storage.http_client` | -- | -- | The http client options to the storage.<br/>**It's only used when the storage type is `S3`, `Oss`, `Gcs` and `Azblob`**. |
| `storage.http_client.pool_max_idle_per_host` | Integer | `1024` | The maximum idle connection per host allowed in the pool. |
| `storage.http_client.connect_timeout` | String | `30s` | The timeout for only the connect phase of a http client. |
| `storage.http_client.timeout` | String | `30s` | The total request timeout, applied from when the request starts connecting until the response body has finished.<br/>Also considered a total deadline. |
| `storage.http_client.pool_idle_timeout` | String | `90s` | The timeout for idle sockets being kept-alive. |
| `[[region_engine]]` | -- | -- | The region engine options. You can configure multiple region engines. |
| `region_engine.mito` | -- | -- | The Mito engine options. |
| `region_engine.mito.num_workers` | Integer | `8` | Number of region workers. |
| `region_engine.mito.worker_channel_size` | Integer | `128` | Request channel size of each worker. |
| `region_engine.mito.worker_request_batch_size` | Integer | `64` | Max batch size for a worker to handle requests. |
| `region_engine.mito.manifest_checkpoint_distance` | Integer | `10` | Number of meta action updated to trigger a new checkpoint for the manifest. |
| `region_engine.mito.compress_manifest` | Bool | `false` | Whether to compress manifest and checkpoint file by gzip (default false). |
| `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.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`. |
| `region_engine.mito.sst_meta_cache_size` | String | Auto | Cache size for SST metadata. Setting it to 0 to disable the cache.<br/>If not set, it's default to 1/32 of OS memory with a max limitation of 128MB. |
| `region_engine.mito.vector_cache_size` | String | Auto | Cache size for vectors and arrow arrays. Setting it to 0 to disable the cache.<br/>If not set, it's default to 1/16 of OS memory with a max limitation of 512MB. |
| `region_engine.mito.page_cache_size` | String | Auto | Cache size for pages of SST row groups. Setting it to 0 to disable the cache.<br/>If not set, it's default to 1/8 of OS memory. |
| `region_engine.mito.selector_result_cache_size` | String | Auto | Cache size for time series selector (e.g. `last_value()`). Setting it to 0 to disable the cache.<br/>If not set, it's default to 1/16 of OS memory with a max limitation of 512MB. |
| `region_engine.mito.enable_write_cache` | Bool | `false` | Whether to enable the write cache, it's enabled by default when using object storage. It is recommended to enable it when using object storage for better performance. |
| `region_engine.mito.write_cache_path` | String | `""` | File system path for write cache, defaults to `{data_home}`. |
| `region_engine.mito.write_cache_size` | String | `5GiB` | Capacity for write cache. If your disk space is sufficient, it is recommended to set it larger. |
| `region_engine.mito.write_cache_ttl` | String | Unset | TTL for write cache. |
| `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.allow_stale_entries` | Bool | `false` | Whether to allow stale WAL entries read during replay. |
| `region_engine.mito.min_compaction_interval` | String | `0m` | Minimum time interval between two compactions.<br/>To align with the old behavior, the default value is 0 (no restrictions). |
| `region_engine.mito.index` | -- | -- | The options for index in Mito engine. |
| `region_engine.mito.index.aux_path` | String | `""` | Auxiliary directory path for the index in filesystem, used to store intermediate files for<br/>creating the index and staging files for searching the index, defaults to `{data_home}/index_intermediate`.<br/>The default name for this directory is `index_intermediate` for backward compatibility.<br/><br/>This path contains two subdirectories:<br/>- `__intm`: for storing intermediate files used during creating index.<br/>- `staging`: for storing staging files used during searching index. |
| `region_engine.mito.index.staging_size` | String | `2GB` | The max capacity of the staging directory. |
| `region_engine.mito.index.metadata_cache_size` | String | `64MiB` | Cache size for inverted index metadata. |
| `region_engine.mito.index.content_cache_size` | String | `128MiB` | Cache size for inverted index content. |
| `region_engine.mito.index.content_cache_page_size` | String | `64KiB` | Page size for inverted index content cache. |
| `region_engine.mito.inverted_index` | -- | -- | The options for inverted index in Mito engine. |
| `region_engine.mito.inverted_index.create_on_flush` | String | `auto` | Whether to create the index on flush.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.inverted_index.create_on_compaction` | String | `auto` | Whether to create the index on compaction.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.inverted_index.apply_on_query` | String | `auto` | Whether to apply the index on query<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.inverted_index.mem_threshold_on_create` | String | `auto` | Memory threshold for performing an external sort during index creation.<br/>- `auto`: automatically determine the threshold based on the system memory size (default)<br/>- `unlimited`: no memory limit<br/>- `[size]` e.g. `64MB`: fixed memory threshold |
| `region_engine.mito.inverted_index.intermediate_path` | String | `""` | Deprecated, use `region_engine.mito.index.aux_path` instead. |
| `region_engine.mito.fulltext_index` | -- | -- | The options for full-text index in Mito engine. |
| `region_engine.mito.fulltext_index.create_on_flush` | String | `auto` | Whether to create the index on flush.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.fulltext_index.create_on_compaction` | String | `auto` | Whether to create the index on compaction.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.fulltext_index.apply_on_query` | String | `auto` | Whether to apply the index on query<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.fulltext_index.mem_threshold_on_create` | String | `auto` | Memory threshold for index creation.<br/>- `auto`: automatically determine the threshold based on the system memory size (default)<br/>- `unlimited`: no memory limit<br/>- `[size]` e.g. `64MB`: fixed memory threshold |
| `region_engine.mito.bloom_filter_index` | -- | -- | The options for bloom filter in Mito engine. |
| `region_engine.mito.bloom_filter_index.create_on_flush` | String | `auto` | Whether to create the bloom filter on flush.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.bloom_filter_index.create_on_compaction` | String | `auto` | Whether to create the bloom filter on compaction.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.bloom_filter_index.apply_on_query` | String | `auto` | Whether to apply the bloom filter on query<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.bloom_filter_index.mem_threshold_on_create` | String | `auto` | Memory threshold for bloom filter creation.<br/>- `auto`: automatically determine the threshold based on the system memory size (default)<br/>- `unlimited`: no memory limit<br/>- `[size]` e.g. `64MB`: fixed memory threshold |
| `region_engine.mito.memtable` | -- | -- | -- |
| `region_engine.mito.memtable.type` | String | `time_series` | Memtable type.<br/>- `time_series`: time-series memtable<br/>- `partition_tree`: partition tree memtable (experimental) |
| `region_engine.mito.memtable.index_max_keys_per_shard` | Integer | `8192` | The max number of keys in one shard.<br/>Only available for `partition_tree` memtable. |
| `region_engine.mito.memtable.data_freeze_threshold` | Integer | `32768` | The max rows of data inside the actively writing buffer in one shard.<br/>Only available for `partition_tree` memtable. |
| `region_engine.mito.memtable.fork_dictionary_bytes` | String | `1GiB` | Max dictionary bytes.<br/>Only available for `partition_tree` memtable. |
| `region_engine.file` | -- | -- | Enable the file engine. |
| `logging` | -- | -- | The logging options. |
| `logging.dir` | String | `/tmp/greptimedb/logs` | The directory to store the log files. If set to empty, logs will not be written to files. |
| `logging.level` | String | Unset | The log level. Can be `info`/`debug`/`warn`/`error`. |
| `logging.enable_otlp_tracing` | Bool | `false` | Enable OTLP tracing. |
| `logging.otlp_endpoint` | String | `http://localhost:4317` | The OTLP tracing endpoint. |
| `logging.append_stdout` | Bool | `true` | Whether to append logs to stdout. |
| `logging.log_format` | String | `text` | The log format. Can be `text`/`json`. |
| `logging.max_log_files` | Integer | `720` | The maximum amount of log files. |
| `logging.tracing_sample_ratio` | -- | -- | The percentage of tracing will be sampled and exported.<br/>Valid range `[0, 1]`, 1 means all traces are sampled, 0 means all traces are not sampled, the default value is 1.<br/>ratio > 1 are treated as 1. Fractions < 0 are treated as 0 |
| `logging.tracing_sample_ratio.default_ratio` | Float | `1.0` | -- |
| `logging.slow_query` | -- | -- | The slow query log options. |
| `logging.slow_query.enable` | Bool | `false` | Whether to enable slow query log. |
| `logging.slow_query.threshold` | String | Unset | The threshold of slow query. |
| `logging.slow_query.sample_ratio` | Float | Unset | The sampling ratio of slow query log. The value should be in the range of (0, 1]. |
| `export_metrics` | -- | -- | The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.<br/>This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape. |
| `export_metrics.enable` | Bool | `false` | whether enable export metrics. |
| `export_metrics.write_interval` | String | `30s` | The interval of export metrics. |
| `export_metrics.self_import` | -- | -- | For `standalone` mode, `self_import` is recommended to collect metrics generated by itself<br/>You must create the database before enabling it. |
| `export_metrics.self_import.db` | String | Unset | -- |
| `export_metrics.remote_write` | -- | -- | -- |
| `export_metrics.remote_write.url` | String | `""` | The url the metrics send to. The url example can be: `http://127.0.0.1:4000/v1/prometheus/write?db=greptime_metrics`. |
| `export_metrics.remote_write.headers` | InlineTable | -- | HTTP headers of Prometheus remote-write carry. |
| `tracing` | -- | -- | The tracing options. Only effect when compiled with `tokio-console` feature. |
| `tracing.tokio_console_addr` | String | Unset | The tokio console address. |


## Distributed Mode

### Frontend

| Key | Type | Default | Descriptions |
| --- | -----| ------- | ----------- |
| `default_timezone` | String | Unset | The default timezone of the server. |
| `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. |
| `heartbeat` | -- | -- | The heartbeat options. |
| `heartbeat.interval` | String | `18s` | Interval for sending heartbeat messages to the metasrv. |
| `heartbeat.retry_interval` | String | `3s` | Interval for retrying to send heartbeat messages to the metasrv. |
| `http` | -- | -- | The HTTP server options. |
| `http.addr` | String | `127.0.0.1:4000` | The address to bind the HTTP server. |
| `http.timeout` | String | `30s` | 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. |
| `grpc` | -- | -- | The gRPC server options. |
| `grpc.addr` | String | `127.0.0.1:4001` | The address to bind the gRPC server. |
| `grpc.hostname` | String | `127.0.0.1:4001` | The hostname advertised to the metasrv,<br/>and used for connections from outside the host |
| `grpc.runtime_size` | Integer | `8` | The number of server worker threads. |
| `grpc.tls` | -- | -- | gRPC server TLS options, see `mysql.tls` section. |
| `grpc.tls.mode` | String | `disable` | TLS mode. |
| `grpc.tls.cert_path` | String | Unset | Certificate file path. |
| `grpc.tls.key_path` | String | Unset | Private key file path. |
| `grpc.tls.watch` | Bool | `false` | Watch for Certificate and key file change and auto reload.<br/>For now, gRPC tls config does not support auto reload. |
| `mysql` | -- | -- | MySQL server options. |
| `mysql.enable` | Bool | `true` | Whether to enable. |
| `mysql.addr` | String | `127.0.0.1:4002` | The addr to bind the MySQL server. |
| `mysql.runtime_size` | Integer | `2` | The number of server worker threads. |
| `mysql.tls` | -- | -- | -- |
| `mysql.tls.mode` | String | `disable` | TLS mode, refer to https://www.postgresql.org/docs/current/libpq-ssl.html<br/>- `disable` (default value)<br/>- `prefer`<br/>- `require`<br/>- `verify-ca`<br/>- `verify-full` |
| `mysql.tls.cert_path` | String | Unset | Certificate file path. |
| `mysql.tls.key_path` | String | Unset | Private key file path. |
| `mysql.tls.watch` | Bool | `false` | Watch for Certificate and key file change and auto reload |
| `postgres` | -- | -- | PostgresSQL server options. |
| `postgres.enable` | Bool | `true` | Whether to enable |
| `postgres.addr` | String | `127.0.0.1:4003` | The addr to bind the PostgresSQL server. |
| `postgres.runtime_size` | Integer | `2` | The number of server worker threads. |
| `postgres.tls` | -- | -- | PostgresSQL server TLS options, see `mysql.tls` section. |
| `postgres.tls.mode` | String | `disable` | TLS mode. |
| `postgres.tls.cert_path` | String | Unset | Certificate file path. |
| `postgres.tls.key_path` | String | Unset | Private key file path. |
| `postgres.tls.watch` | Bool | `false` | Watch for Certificate and key file change and auto reload |
| `opentsdb` | -- | -- | OpenTSDB protocol options. |
| `opentsdb.enable` | Bool | `true` | Whether to enable OpenTSDB put in HTTP API. |
| `influxdb` | -- | -- | InfluxDB protocol options. |
| `influxdb.enable` | Bool | `true` | Whether to enable InfluxDB protocol in HTTP API. |
| `prom_store` | -- | -- | Prometheus remote storage options |
| `prom_store.enable` | Bool | `true` | Whether to enable Prometheus remote write and read in HTTP API. |
| `prom_store.with_metric_engine` | Bool | `true` | Whether to store the data from Prometheus remote write in metric engine. |
| `meta_client` | -- | -- | The metasrv client options. |
| `meta_client.metasrv_addrs` | Array | -- | The addresses of the metasrv. |
| `meta_client.timeout` | String | `3s` | Operation timeout. |
| `meta_client.heartbeat_timeout` | String | `500ms` | Heartbeat timeout. |
| `meta_client.ddl_timeout` | String | `10s` | DDL timeout. |
| `meta_client.connect_timeout` | String | `1s` | Connect server timeout. |
| `meta_client.tcp_nodelay` | Bool | `true` | `TCP_NODELAY` option for accepted connections. |
| `meta_client.metadata_cache_max_capacity` | Integer | `100000` | The configuration about the cache of the metadata. |
| `meta_client.metadata_cache_ttl` | String | `10m` | TTL of the metadata cache. |
| `meta_client.metadata_cache_tti` | String | `5m` | -- |
| `datanode` | -- | -- | Datanode options. |
| `datanode.client` | -- | -- | Datanode client options. |
| `datanode.client.connect_timeout` | String | `10s` | -- |
| `datanode.client.tcp_nodelay` | Bool | `true` | -- |
| `logging` | -- | -- | The logging options. |
| `logging.dir` | String | `/tmp/greptimedb/logs` | The directory to store the log files. If set to empty, logs will not be written to files. |
| `logging.level` | String | Unset | The log level. Can be `info`/`debug`/`warn`/`error`. |
| `logging.enable_otlp_tracing` | Bool | `false` | Enable OTLP tracing. |
| `logging.otlp_endpoint` | String | `http://localhost:4317` | The OTLP tracing endpoint. |
| `logging.append_stdout` | Bool | `true` | Whether to append logs to stdout. |
| `logging.log_format` | String | `text` | The log format. Can be `text`/`json`. |
| `logging.max_log_files` | Integer | `720` | The maximum amount of log files. |
| `logging.tracing_sample_ratio` | -- | -- | The percentage of tracing will be sampled and exported.<br/>Valid range `[0, 1]`, 1 means all traces are sampled, 0 means all traces are not sampled, the default value is 1.<br/>ratio > 1 are treated as 1. Fractions < 0 are treated as 0 |
| `logging.tracing_sample_ratio.default_ratio` | Float | `1.0` | -- |
| `logging.slow_query` | -- | -- | The slow query log options. |
| `logging.slow_query.enable` | Bool | `false` | Whether to enable slow query log. |
| `logging.slow_query.threshold` | String | Unset | The threshold of slow query. |
| `logging.slow_query.sample_ratio` | Float | Unset | The sampling ratio of slow query log. The value should be in the range of (0, 1]. |
| `export_metrics` | -- | -- | The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.<br/>This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape. |
| `export_metrics.enable` | Bool | `false` | whether enable export metrics. |
| `export_metrics.write_interval` | String | `30s` | The interval of export metrics. |
| `export_metrics.self_import` | -- | -- | For `standalone` mode, `self_import` is recommend to collect metrics generated by itself<br/>You must create the database before enabling it. |
| `export_metrics.self_import.db` | String | Unset | -- |
| `export_metrics.remote_write` | -- | -- | -- |
| `export_metrics.remote_write.url` | String | `""` | The url the metrics send to. The url example can be: `http://127.0.0.1:4000/v1/prometheus/write?db=greptime_metrics`. |
| `export_metrics.remote_write.headers` | InlineTable | -- | HTTP headers of Prometheus remote-write carry. |
| `tracing` | -- | -- | The tracing options. Only effect when compiled with `tokio-console` feature. |
| `tracing.tokio_console_addr` | String | Unset | The tokio console address. |


### Metasrv

| Key | Type | Default | Descriptions |
| --- | -----| ------- | ----------- |
| `data_home` | String | `/tmp/metasrv/` | The working home directory. |
| `bind_addr` | String | `127.0.0.1:3002` | The bind address of metasrv. |
| `server_addr` | String | `127.0.0.1:3002` | The communication server address for frontend and datanode to connect to metasrv,  "127.0.0.1:3002" by default for localhost. |
| `store_addrs` | Array | -- | Store server address default to etcd store.<br/>For postgres store, the format is:<br/>"password=password dbname=postgres user=postgres host=localhost port=5432"<br/>For etcd store, the format is:<br/>"127.0.0.1:2379" |
| `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` |
| `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_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). |
| `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. |
| `runtime.compact_rt_size` | Integer | `4` | The number of threads to execute the runtime for global write operations. |
| `procedure` | -- | -- | Procedure storage options. |
| `procedure.max_retry_times` | Integer | `12` | Procedure max retry time. |
| `procedure.retry_delay` | String | `500ms` | Initial retry delay of procedures, increases exponentially |
| `procedure.max_metadata_value_size` | String | `1500KiB` | Auto split large value<br/>GreptimeDB procedure uses etcd as the default metadata storage backend.<br/>The etcd the maximum size of any request is 1.5 MiB<br/>1500KiB = 1536KiB (1.5MiB) - 36KiB (reserved size of key)<br/>Comments out the `max_metadata_value_size`, for don't split large value (no limit). |
| `failure_detector` | -- | -- | -- |
| `failure_detector.threshold` | Float | `8.0` | The threshold value used by the failure detector to determine failure conditions. |
| `failure_detector.min_std_deviation` | String | `100ms` | The minimum standard deviation of the heartbeat intervals, used to calculate acceptable variations. |
| `failure_detector.acceptable_heartbeat_pause` | String | `10000ms` | The acceptable pause duration between heartbeats, used to determine if a heartbeat interval is acceptable. |
| `failure_detector.first_heartbeat_estimate` | String | `1000ms` | The initial estimate of the heartbeat interval used by the failure detector. |
| `datanode` | -- | -- | Datanode options. |
| `datanode.client` | -- | -- | Datanode client options. |
| `datanode.client.timeout` | String | `10s` | Operation timeout. |
| `datanode.client.connect_timeout` | String | `10s` | Connect server timeout. |
| `datanode.client.tcp_nodelay` | Bool | `true` | `TCP_NODELAY` option for accepted connections. |
| `wal` | -- | -- | -- |
| `wal.provider` | String | `raft_engine` | -- |
| `wal.broker_endpoints` | Array | -- | The broker endpoints of the Kafka cluster. |
| `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. |
| `wal.selector_type` | String | `round_robin` | Topic selector type.<br/>Available selector types:<br/>- `round_robin` (default) |
| `wal.topic_name_prefix` | String | `greptimedb_wal_topic` | A Kafka topic is constructed by concatenating `topic_name_prefix` and `topic_id`.<br/>i.g., greptimedb_wal_topic_0, greptimedb_wal_topic_1. |
| `wal.replication_factor` | Integer | `1` | Expected number of replicas of each partition. |
| `wal.create_topic_timeout` | String | `30s` | Above which a topic creation operation will be cancelled. |
| `wal.backoff_init` | String | `500ms` | The initial backoff for kafka clients. |
| `wal.backoff_max` | String | `10s` | The maximum backoff for kafka clients. |
| `wal.backoff_base` | Integer | `2` | Exponential backoff rate, i.e. next backoff = base * current backoff. |
| `wal.backoff_deadline` | String | `5mins` | Stop reconnecting if the total wait time reaches the deadline. If this config is missing, the reconnecting won't terminate. |
| `logging` | -- | -- | The logging options. |
| `logging.dir` | String | `/tmp/greptimedb/logs` | The directory to store the log files. If set to empty, logs will not be written to files. |
| `logging.level` | String | Unset | The log level. Can be `info`/`debug`/`warn`/`error`. |
| `logging.enable_otlp_tracing` | Bool | `false` | Enable OTLP tracing. |
| `logging.otlp_endpoint` | String | `http://localhost:4317` | The OTLP tracing endpoint. |
| `logging.append_stdout` | Bool | `true` | Whether to append logs to stdout. |
| `logging.log_format` | String | `text` | The log format. Can be `text`/`json`. |
| `logging.max_log_files` | Integer | `720` | The maximum amount of log files. |
| `logging.tracing_sample_ratio` | -- | -- | The percentage of tracing will be sampled and exported.<br/>Valid range `[0, 1]`, 1 means all traces are sampled, 0 means all traces are not sampled, the default value is 1.<br/>ratio > 1 are treated as 1. Fractions < 0 are treated as 0 |
| `logging.tracing_sample_ratio.default_ratio` | Float | `1.0` | -- |
| `logging.slow_query` | -- | -- | The slow query log options. |
| `logging.slow_query.enable` | Bool | `false` | Whether to enable slow query log. |
| `logging.slow_query.threshold` | String | Unset | The threshold of slow query. |
| `logging.slow_query.sample_ratio` | Float | Unset | The sampling ratio of slow query log. The value should be in the range of (0, 1]. |
| `export_metrics` | -- | -- | The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.<br/>This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape. |
| `export_metrics.enable` | Bool | `false` | whether enable export metrics. |
| `export_metrics.write_interval` | String | `30s` | The interval of export metrics. |
| `export_metrics.self_import` | -- | -- | For `standalone` mode, `self_import` is recommend to collect metrics generated by itself<br/>You must create the database before enabling it. |
| `export_metrics.self_import.db` | String | Unset | -- |
| `export_metrics.remote_write` | -- | -- | -- |
| `export_metrics.remote_write.url` | String | `""` | The url the metrics send to. The url example can be: `http://127.0.0.1:4000/v1/prometheus/write?db=greptime_metrics`. |
| `export_metrics.remote_write.headers` | InlineTable | -- | HTTP headers of Prometheus remote-write carry. |
| `tracing` | -- | -- | The tracing options. Only effect when compiled with `tokio-console` feature. |
| `tracing.tokio_console_addr` | String | Unset | The tokio console address. |


### Datanode

| Key | Type | Default | Descriptions |
| --- | -----| ------- | ----------- |
| `mode` | String | `standalone` | The running mode of the datanode. It can be `standalone` or `distributed`. |
| `node_id` | Integer | Unset | The datanode identifier and should be unique in the cluster. |
| `require_lease_before_startup` | Bool | `false` | Start services after regions have obtained leases.<br/>It will block the datanode start if it can't receive leases in the heartbeat from metasrv. |
| `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. |
| `rpc_addr` | String | Unset | Deprecated, use `grpc.addr` instead. |
| `rpc_hostname` | String | Unset | Deprecated, use `grpc.hostname` instead. |
| `rpc_runtime_size` | Integer | Unset | Deprecated, use `grpc.runtime_size` instead. |
| `rpc_max_recv_message_size` | String | Unset | Deprecated, use `grpc.rpc_max_recv_message_size` instead. |
| `rpc_max_send_message_size` | String | Unset | Deprecated, use `grpc.rpc_max_send_message_size` instead. |
| `enable_telemetry` | Bool | `true` | Enable telemetry to collect anonymous usage data. Enabled by default. |
| `http` | -- | -- | The HTTP server options. |
| `http.addr` | String | `127.0.0.1:4000` | The address to bind the HTTP server. |
| `http.timeout` | String | `30s` | 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. |
| `grpc` | -- | -- | The gRPC server options. |
| `grpc.addr` | String | `127.0.0.1:3001` | The address to bind the gRPC server. |
| `grpc.hostname` | String | `127.0.0.1:3001` | The hostname advertised to the metasrv,<br/>and used for connections from outside the host |
| `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.tls` | -- | -- | gRPC server TLS options, see `mysql.tls` section. |
| `grpc.tls.mode` | String | `disable` | TLS mode. |
| `grpc.tls.cert_path` | String | Unset | Certificate file path. |
| `grpc.tls.key_path` | String | Unset | Private key file path. |
| `grpc.tls.watch` | Bool | `false` | Watch for Certificate and key file change and auto reload.<br/>For now, gRPC tls config does not support auto reload. |
| `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. |
| `heartbeat` | -- | -- | The heartbeat options. |
| `heartbeat.interval` | String | `3s` | Interval for sending heartbeat messages to the metasrv. |
| `heartbeat.retry_interval` | String | `3s` | Interval for retrying to send heartbeat messages to the metasrv. |
| `meta_client` | -- | -- | The metasrv client options. |
| `meta_client.metasrv_addrs` | Array | -- | The addresses of the metasrv. |
| `meta_client.timeout` | String | `3s` | Operation timeout. |
| `meta_client.heartbeat_timeout` | String | `500ms` | Heartbeat timeout. |
| `meta_client.ddl_timeout` | String | `10s` | DDL timeout. |
| `meta_client.connect_timeout` | String | `1s` | Connect server timeout. |
| `meta_client.tcp_nodelay` | Bool | `true` | `TCP_NODELAY` option for accepted connections. |
| `meta_client.metadata_cache_max_capacity` | Integer | `100000` | The configuration about the cache of the metadata. |
| `meta_client.metadata_cache_ttl` | String | `10m` | TTL of the metadata cache. |
| `meta_client.metadata_cache_tti` | String | `5m` | -- |
| `wal` | -- | -- | The WAL options. |
| `wal.provider` | String | `raft_engine` | The provider of the WAL.<br/>- `raft_engine`: the wal is stored in the local file system by raft-engine.<br/>- `kafka`: it's remote wal that data is stored in Kafka. |
| `wal.dir` | String | Unset | The directory to store the WAL files.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.file_size` | String | `128MB` | The size of the WAL segment file.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.purge_threshold` | String | `1GB` | The threshold of the WAL size to trigger a flush.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.purge_interval` | String | `1m` | The interval to trigger a flush.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.read_batch_size` | Integer | `128` | The read batch size.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.sync_write` | Bool | `false` | Whether to use sync write.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.enable_log_recycle` | Bool | `true` | Whether to reuse logically truncated log files.<br/>**It's only used when the provider is `raft_engine`**. |
| `wal.prefill_log_files` | Bool | `false` | Whether to pre-create log files on start up.<br/>**It's only used when the provider is `raft_engine`**. |
| `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.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.backoff_init` | String | `500ms` | The initial backoff delay.<br/>**It's only used when the provider is `kafka`**. |
| `wal.backoff_max` | String | `10s` | The maximum backoff delay.<br/>**It's only used when the provider is `kafka`**. |
| `wal.backoff_base` | Integer | `2` | The exponential backoff rate, i.e. next backoff = base * current backoff.<br/>**It's only used when the provider is `kafka`**. |
| `wal.backoff_deadline` | String | `5mins` | The deadline of retries.<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`**. |
| `wal.dump_index_interval` | String | `60s` | The interval for dumping WAL indexes.<br/>**It's only used when the provider is `kafka`**. |
| `wal.overwrite_entry_start_id` | Bool | `false` | Ignore missing entries during read WAL.<br/>**It's only used when the provider is `kafka`**.<br/><br/>This option ensures that when Kafka messages are deleted, the system<br/>can still successfully replay memtable data without throwing an<br/>out-of-range error.<br/>However, enabling this option might lead to unexpected data loss,<br/>as the system will skip over missing entries instead of treating<br/>them as critical errors. |
| `storage` | -- | -- | The data storage options. |
| `storage.data_home` | String | `/tmp/greptimedb/` | 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.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`**. |
| `storage.secret_access_key` | String | Unset | The secret access key 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`**. |
| `storage.access_key_secret` | String | Unset | The secret access key of the aliyun account.<br/>**It's only used when the storage type is `Oss`**. |
| `storage.account_name` | String | Unset | The account key of the azure account.<br/>**It's only used when the storage type is `Azblob`**. |
| `storage.account_key` | String | Unset | The account key of the azure account.<br/>**It's only used when the storage type is `Azblob`**. |
| `storage.scope` | String | Unset | The scope of the google cloud storage.<br/>**It's only used when the storage type is `Gcs`**. |
| `storage.credential_path` | String | Unset | The credential path of the google cloud storage.<br/>**It's only used when the storage type is `Gcs`**. |
| `storage.credential` | String | Unset | The credential of the google cloud storage.<br/>**It's only used when the storage type is `Gcs`**. |
| `storage.container` | String | Unset | The container of the azure account.<br/>**It's only used when the storage type is `Azblob`**. |
| `storage.sas_token` | String | Unset | The sas token of the azure account.<br/>**It's only used when the storage type is `Azblob`**. |
| `storage.endpoint` | String | Unset | The endpoint of the S3 service.<br/>**It's only used when the storage type is `S3`, `Oss`, `Gcs` and `Azblob`**. |
| `storage.region` | String | Unset | The region of the S3 service.<br/>**It's only used when the storage type is `S3`, `Oss`, `Gcs` and `Azblob`**. |
| `storage.http_client` | -- | -- | The http client options to the storage.<br/>**It's only used when the storage type is `S3`, `Oss`, `Gcs` and `Azblob`**. |
| `storage.http_client.pool_max_idle_per_host` | Integer | `1024` | The maximum idle connection per host allowed in the pool. |
| `storage.http_client.connect_timeout` | String | `30s` | The timeout for only the connect phase of a http client. |
| `storage.http_client.timeout` | String | `30s` | The total request timeout, applied from when the request starts connecting until the response body has finished.<br/>Also considered a total deadline. |
| `storage.http_client.pool_idle_timeout` | String | `90s` | The timeout for idle sockets being kept-alive. |
| `[[region_engine]]` | -- | -- | The region engine options. You can configure multiple region engines. |
| `region_engine.mito` | -- | -- | The Mito engine options. |
| `region_engine.mito.num_workers` | Integer | `8` | Number of region workers. |
| `region_engine.mito.worker_channel_size` | Integer | `128` | Request channel size of each worker. |
| `region_engine.mito.worker_request_batch_size` | Integer | `64` | Max batch size for a worker to handle requests. |
| `region_engine.mito.manifest_checkpoint_distance` | Integer | `10` | Number of meta action updated to trigger a new checkpoint for the manifest. |
| `region_engine.mito.compress_manifest` | Bool | `false` | Whether to compress manifest and checkpoint file by gzip (default false). |
| `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.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` |
| `region_engine.mito.sst_meta_cache_size` | String | Auto | Cache size for SST metadata. Setting it to 0 to disable the cache.<br/>If not set, it's default to 1/32 of OS memory with a max limitation of 128MB. |
| `region_engine.mito.vector_cache_size` | String | Auto | Cache size for vectors and arrow arrays. Setting it to 0 to disable the cache.<br/>If not set, it's default to 1/16 of OS memory with a max limitation of 512MB. |
| `region_engine.mito.page_cache_size` | String | Auto | Cache size for pages of SST row groups. Setting it to 0 to disable the cache.<br/>If not set, it's default to 1/8 of OS memory. |
| `region_engine.mito.selector_result_cache_size` | String | Auto | Cache size for time series selector (e.g. `last_value()`). Setting it to 0 to disable the cache.<br/>If not set, it's default to 1/16 of OS memory with a max limitation of 512MB. |
| `region_engine.mito.enable_write_cache` | Bool | `false` | Whether to enable the write cache, it's enabled by default when using object storage. It is recommended to enable it when using object storage for better performance. |
| `region_engine.mito.write_cache_path` | String | `""` | File system path for write cache, defaults to `{data_home}`. |
| `region_engine.mito.write_cache_size` | String | `5GiB` | Capacity for write cache. If your disk space is sufficient, it is recommended to set it larger. |
| `region_engine.mito.write_cache_ttl` | String | Unset | TTL for write cache. |
| `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.allow_stale_entries` | Bool | `false` | Whether to allow stale WAL entries read during replay. |
| `region_engine.mito.min_compaction_interval` | String | `0m` | Minimum time interval between two compactions.<br/>To align with the old behavior, the default value is 0 (no restrictions). |
| `region_engine.mito.index` | -- | -- | The options for index in Mito engine. |
| `region_engine.mito.index.aux_path` | String | `""` | Auxiliary directory path for the index in filesystem, used to store intermediate files for<br/>creating the index and staging files for searching the index, defaults to `{data_home}/index_intermediate`.<br/>The default name for this directory is `index_intermediate` for backward compatibility.<br/><br/>This path contains two subdirectories:<br/>- `__intm`: for storing intermediate files used during creating index.<br/>- `staging`: for storing staging files used during searching index. |
| `region_engine.mito.index.staging_size` | String | `2GB` | The max capacity of the staging directory. |
| `region_engine.mito.index.metadata_cache_size` | String | `64MiB` | Cache size for inverted index metadata. |
| `region_engine.mito.index.content_cache_size` | String | `128MiB` | Cache size for inverted index content. |
| `region_engine.mito.index.content_cache_page_size` | String | `64KiB` | Page size for inverted index content cache. |
| `region_engine.mito.inverted_index` | -- | -- | The options for inverted index in Mito engine. |
| `region_engine.mito.inverted_index.create_on_flush` | String | `auto` | Whether to create the index on flush.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.inverted_index.create_on_compaction` | String | `auto` | Whether to create the index on compaction.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.inverted_index.apply_on_query` | String | `auto` | Whether to apply the index on query<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.inverted_index.mem_threshold_on_create` | String | `auto` | Memory threshold for performing an external sort during index creation.<br/>- `auto`: automatically determine the threshold based on the system memory size (default)<br/>- `unlimited`: no memory limit<br/>- `[size]` e.g. `64MB`: fixed memory threshold |
| `region_engine.mito.inverted_index.intermediate_path` | String | `""` | Deprecated, use `region_engine.mito.index.aux_path` instead. |
| `region_engine.mito.fulltext_index` | -- | -- | The options for full-text index in Mito engine. |
| `region_engine.mito.fulltext_index.create_on_flush` | String | `auto` | Whether to create the index on flush.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.fulltext_index.create_on_compaction` | String | `auto` | Whether to create the index on compaction.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.fulltext_index.apply_on_query` | String | `auto` | Whether to apply the index on query<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.fulltext_index.mem_threshold_on_create` | String | `auto` | Memory threshold for index creation.<br/>- `auto`: automatically determine the threshold based on the system memory size (default)<br/>- `unlimited`: no memory limit<br/>- `[size]` e.g. `64MB`: fixed memory threshold |
| `region_engine.mito.bloom_filter_index` | -- | -- | The options for bloom filter index in Mito engine. |
| `region_engine.mito.bloom_filter_index.create_on_flush` | String | `auto` | Whether to create the index on flush.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.bloom_filter_index.create_on_compaction` | String | `auto` | Whether to create the index on compaction.<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.bloom_filter_index.apply_on_query` | String | `auto` | Whether to apply the index on query<br/>- `auto`: automatically (default)<br/>- `disable`: never |
| `region_engine.mito.bloom_filter_index.mem_threshold_on_create` | String | `auto` | Memory threshold for the index creation.<br/>- `auto`: automatically determine the threshold based on the system memory size (default)<br/>- `unlimited`: no memory limit<br/>- `[size]` e.g. `64MB`: fixed memory threshold |
| `region_engine.mito.memtable` | -- | -- | -- |
| `region_engine.mito.memtable.type` | String | `time_series` | Memtable type.<br/>- `time_series`: time-series memtable<br/>- `partition_tree`: partition tree memtable (experimental) |
| `region_engine.mito.memtable.index_max_keys_per_shard` | Integer | `8192` | The max number of keys in one shard.<br/>Only available for `partition_tree` memtable. |
| `region_engine.mito.memtable.data_freeze_threshold` | Integer | `32768` | The max rows of data inside the actively writing buffer in one shard.<br/>Only available for `partition_tree` memtable. |
| `region_engine.mito.memtable.fork_dictionary_bytes` | String | `1GiB` | Max dictionary bytes.<br/>Only available for `partition_tree` memtable. |
| `region_engine.file` | -- | -- | Enable the file engine. |
| `logging` | -- | -- | The logging options. |
| `logging.dir` | String | `/tmp/greptimedb/logs` | The directory to store the log files. If set to empty, logs will not be written to files. |
| `logging.level` | String | Unset | The log level. Can be `info`/`debug`/`warn`/`error`. |
| `logging.enable_otlp_tracing` | Bool | `false` | Enable OTLP tracing. |
| `logging.otlp_endpoint` | String | `http://localhost:4317` | The OTLP tracing endpoint. |
| `logging.append_stdout` | Bool | `true` | Whether to append logs to stdout. |
| `logging.log_format` | String | `text` | The log format. Can be `text`/`json`. |
| `logging.max_log_files` | Integer | `720` | The maximum amount of log files. |
| `logging.tracing_sample_ratio` | -- | -- | The percentage of tracing will be sampled and exported.<br/>Valid range `[0, 1]`, 1 means all traces are sampled, 0 means all traces are not sampled, the default value is 1.<br/>ratio > 1 are treated as 1. Fractions < 0 are treated as 0 |
| `logging.tracing_sample_ratio.default_ratio` | Float | `1.0` | -- |
| `logging.slow_query` | -- | -- | The slow query log options. |
| `logging.slow_query.enable` | Bool | `false` | Whether to enable slow query log. |
| `logging.slow_query.threshold` | String | Unset | The threshold of slow query. |
| `logging.slow_query.sample_ratio` | Float | Unset | The sampling ratio of slow query log. The value should be in the range of (0, 1]. |
| `export_metrics` | -- | -- | The datanode can export its metrics and send to Prometheus compatible service (e.g. send to `greptimedb` itself) from remote-write API.<br/>This is only used for `greptimedb` to export its own metrics internally. It's different from prometheus scrape. |
| `export_metrics.enable` | Bool | `false` | whether enable export metrics. |
| `export_metrics.write_interval` | String | `30s` | The interval of export metrics. |
| `export_metrics.self_import` | -- | -- | For `standalone` mode, `self_import` is recommend to collect metrics generated by itself<br/>You must create the database before enabling it. |
| `export_metrics.self_import.db` | String | Unset | -- |
| `export_metrics.remote_write` | -- | -- | -- |
| `export_metrics.remote_write.url` | String | `""` | The url the metrics send to. The url example can be: `http://127.0.0.1:4000/v1/prometheus/write?db=greptime_metrics`. |
| `export_metrics.remote_write.headers` | InlineTable | -- | HTTP headers of Prometheus remote-write carry. |
| `tracing` | -- | -- | The tracing options. Only effect when compiled with `tokio-console` feature. |
| `tracing.tokio_console_addr` | String | Unset | The tokio console address. |


### Flownode

| Key | Type | Default | Descriptions |
| --- | -----| ------- | ----------- |
| `mode` | String | `distributed` | The running mode of the flownode. It can be `standalone` or `distributed`. |
| `node_id` | Integer | Unset | The flownode identifier and should be unique in the cluster. |
| `flow` | -- | -- | flow engine options. |
| `flow.num_workers` | Integer | `0` | The number of flow worker in flownode.<br/>Not setting(or set to 0) this value will use the number of CPU cores divided by 2. |
| `grpc` | -- | -- | The gRPC server options. |
| `grpc.addr` | String | `127.0.0.1:6800` | The address to bind the gRPC server. |
| `grpc.hostname` | String | `127.0.0.1` | The hostname advertised to the metasrv,<br/>and used for connections from outside the host |
| `grpc.runtime_size` | Integer | `2` | 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. |
| `http` | -- | -- | The HTTP server options. |
| `http.addr` | String | `127.0.0.1:4000` | The address to bind the HTTP server. |
| `http.timeout` | String | `30s` | 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. |
| `meta_client` | -- | -- | The metasrv client options. |
| `meta_client.metasrv_addrs` | Array | -- | The addresses of the metasrv. |
| `meta_client.timeout` | String | `3s` | Operation timeout. |
| `meta_client.heartbeat_timeout` | String | `500ms` | Heartbeat timeout. |
| `meta_client.ddl_timeout` | String | `10s` | DDL timeout. |
| `meta_client.connect_timeout` | String | `1s` | Connect server timeout. |
| `meta_client.tcp_nodelay` | Bool | `true` | `TCP_NODELAY` option for accepted connections. |
| `meta_client.metadata_cache_max_capacity` | Integer | `100000` | The configuration about the cache of the metadata. |
| `meta_client.metadata_cache_ttl` | String | `10m` | TTL of the metadata cache. |
| `meta_client.metadata_cache_tti` | String | `5m` | -- |
| `heartbeat` | -- | -- | The heartbeat options. |
| `heartbeat.interval` | String | `3s` | Interval for sending heartbeat messages to the metasrv. |
| `heartbeat.retry_interval` | String | `3s` | Interval for retrying to send heartbeat messages to the metasrv. |
| `logging` | -- | -- | The logging options. |
| `logging.dir` | String | `/tmp/greptimedb/logs` | The directory to store the log files. If set to empty, logs will not be written to files. |
| `logging.level` | String | Unset | The log level. Can be `info`/`debug`/`warn`/`error`. |
| `logging.enable_otlp_tracing` | Bool | `false` | Enable OTLP tracing. |
| `logging.otlp_endpoint` | String | `http://localhost:4317` | The OTLP tracing endpoint. |
| `logging.append_stdout` | Bool | `true` | Whether to append logs to stdout. |
| `logging.log_format` | String | `text` | The log format. Can be `text`/`json`. |
| `logging.max_log_files` | Integer | `720` | The maximum amount of log files. |
| `logging.tracing_sample_ratio` | -- | -- | The percentage of tracing will be sampled and exported.<br/>Valid range `[0, 1]`, 1 means all traces are sampled, 0 means all traces are not sampled, the default value is 1.<br/>ratio > 1 are treated as 1. Fractions < 0 are treated as 0 |
| `logging.tracing_sample_ratio.default_ratio` | Float | `1.0` | -- |
| `logging.slow_query` | -- | -- | The slow query log options. |
| `logging.slow_query.enable` | Bool | `false` | Whether to enable slow query log. |
| `logging.slow_query.threshold` | String | Unset | The threshold of slow query. |
| `logging.slow_query.sample_ratio` | Float | Unset | The sampling ratio of slow query log. The value should be in the range of (0, 1]. |
| `tracing` | -- | -- | The tracing options. Only effect when compiled with `tokio-console` feature. |
| `tracing.tokio_console_addr` | String | Unset | The tokio console address. |
