Configuration

GreptimeDB supports layered configuration and uses the following precedence order(each item takes precedence over the item below it):

• Command-line options
• Configuration file
• Environment variables
• Default values

This page describes methods for configuring GreptimeDB server settings. Configuration can be set in TOML file.

The system assigns a default value for missing parameters in the configuration file.

All sample configuration files are in the project’s config folder.

Command-line options

See Command lines to learn how to use the greptime command line.

Global options

• -h/--help: Print help information;
• -V/--version: Print version information;
• --log-dir <LOG_DIR>: The logging directory;
• --log-level <LOG_LEVEL>: The logging level;

Datanode subcommand options

You can list all the options from the following command:

greptime datanode start --help

• -c/--config-file: The configuration file for datanode;
• --data-home: Database storage root directory;
• --env-prefix <ENV_PREFIX>: The prefix of environment variables, default is GREPTIMEDB_DATANODE;
• --http-addr <HTTP_ADDR>: HTTP server address;
• --http-timeout <HTTP_TIMEOUT>: HTTP request timeout in seconds.
• --metasrv-addrs <METASRV_ADDR>: Metasrv address list;
• --node-id <NODE_ID>: The datanode ID;
• --rpc-addr <RPC_ADDR>: The datanode RPC addr;
• --rpc-hostname <RPC_HOSTNAME>: The datanode hostname;
• --wal-dir <WAL_DIR>: The directory of WAL;

All the addr options are in the form of ip:port.

Metasrv subcommand options

You can list all the options from the following command:

greptime metasrv start --help

• -c/--config-file: The configuration file for metasrv;
• --enable-region-failover: Whether to enable region failover, default is false.
• --env-prefix <ENV_PREFIX>: The prefix of environment variables, default is GREPTIMEDB_METASRV;
• --bind-addr <BIND_ADDR>: The bind address of metasrv;
• --http-addr <HTTP_ADDR>: HTTP server address;
• --http-timeout <HTTP_TIMEOUT>: HTTP request timeout in seconds.
• --selector <SELECTOR>: You can refer selector-type;
• --server-addr <SERVER_ADDR>: The communication server address for frontend and datanode to connect to metasrv;
• --store-addrs <STORE_ADDR>: Comma or space separated key-value storage server (default is etcd) address, used for storing metadata;
• --use-memory-store: Use memory store instead of etcd, for test purpose only;

Frontend subcommand options

You can list all the options from the following command:

greptime frontend start --help

• -c/--config-file: The configuration file for frontend;
• --disable-dashboard: Disable dashboard http service, default is false.
• --env-prefix <ENV_PREFIX>: The prefix of environment variables, default is GREPTIMEDB_FRONTEND;
• --rpc-addr <RPC_ADDR>: GRPC server address;
• --http-addr <HTTP_ADDR>: HTTP server address;
• --http-timeout <HTTP_TIMEOUT>: HTTP request timeout in seconds.
• --influxdb-enable: Whether to enable InfluxDB protocol in HTTP API;
• --metasrv-addr <METASRV_ADDR>: Metasrv address list;
• --mysql-addr <MYSQL_ADDR>: MySQL server address;
• --postgres-addr <POSTGRES_ADDR>: Postgres server address;
• --tls-cert-path <TLS_CERT_PATH>: The TLS public key file path;
• --tls-key-path <TLS_KEY_PATH>: The TLS private key file path;
• --tls-mode <TLS_MODE>: TLS Mode;
• --user-provider <USER_PROVIDER>: You can refer authentication;

Standalone subcommand options

You can list all the options from the following command:

greptime standalone start --help

• -c/--config-file: The configuration file for frontend;
• --env-prefix <ENV_PREFIX>: The prefix of environment variables, default is GREPTIMEDB_STANDALONE;
• --http-addr <HTTP_ADDR>: HTTP server address;
• --influxdb-enable: Whether to enable InfluxDB protocol in HTTP API;
• --mysql-addr <MYSQL_ADDR>: MySQL server address;
• --postgres-addr <POSTGRES_ADDR>: Postgres server address;
• --rpc-addr <RPC_ADDR>: gRPC server address;

Configuration File

Examples

Configurations can be used in one or multiple components according to their features. This document only contains examples for frequently used configurations. Please refer to the auto-generated document for all available configurations.

You can find all available configurations for each component on GitHub:

• standalone
• frontend
• datanode
• metasrv

Specify configuration file

You can specify the configuration file by using the command line arg -c [file_path].

greptime [standalone | frontend | datanode | metasrv]  start -c config/standalone.example.toml

For example, start the standalone as below:

greptime standalone start -c standalone.example.toml

Protocol options

Protocol options are valid in frontend and standalone sub commands, which specify the protocol server addresses and other protocol-related options.

Below is an example configuration with default values. The HTTP and gRPC protocols must be enabled for the database to work correctly. The other protocols are optional. If you want to disable certain protocols, such as OpenTSDB protocol support, you can set the enable parameter to false.

[http]
addr = "127.0.0.1:4000"
timeout = "30s"
body_limit = "64MB"
[grpc]
addr = "127.0.0.1:4001"
runtime_size = 8
[mysql]
enable = true
addr = "127.0.0.1:4002"
runtime_size = 2
[mysql.tls]
mode = "disable"
cert_path = ""
key_path = ""
[postgres]
enable = true
addr = "127.0.0.1:4003"
runtime_size = 2
[postgres.tls]
mode = "disable"
cert_path = ""
key_path = ""
[opentsdb]
enable = true
[influxdb]
enable = true
[prom_store]
enable = true
with_metric_engine = true

The following table describes the options in detail:

Storage options

The storage options are valid in datanode and standalone mode, which specify the database data directory and other storage-related options.

GreptimeDB supports storing data in local file system, AWS S3 and compatible services (including MinIO, digitalocean space, Tencent Cloud Object Storage(COS), Baidu Object Storage(BOS) and so on), Azure Blob Storage and Aliyun OSS.

A file storage sample configuration:

[storage]
type = "File"
data_home = "/tmp/greptimedb/"

A S3 storage sample configuration:

[storage]
type = "S3"
bucket = "test_greptimedb"
root = "/greptimedb"
access_key_id = "<access key id>"
secret_access_key = "<secret access key>"

Storage engine provider

[[storage.providers]] setups the table storage engine providers. Based on these providers, you can create a table with a specified storage, see create table:

# Allows using multiple storages
[[storage.providers]]
type = "S3"
bucket = "test_greptimedb"
root = "/greptimedb"
access_key_id = "<access key id>"
secret_access_key = "<secret access key>"
[[storage.providers]]
type = "Gcs"
bucket = "test_greptimedb"
root = "/greptimedb"
credential_path = "<gcs credential path>"

All configured providers can be used as the storage option when creating tables.

Object storage cache

When using S3, OSS or Azure Blob Storage, it’s better to enable object storage caching for speedup data querying:

[storage]
type = "S3"
bucket = "test_greptimedb"
root = "/greptimedb"
access_key_id = "<access key id>"
secret_access_key = "<secret access key>"
## Enable object storage caching
cache_path = "/var/data/s3_local_cache"
cache_capacity = "256MiB"

The cache_path is the local file directory that keeps cache files, and the cache_capacity is the maximum total file size in the cache directory.

WAL options

The [wal] section in datanode or standalone config file configures the options of Write-Ahead-Log:

[wal]
file_size = "256MB"
purge_threshold = "4GB"
purge_interval = "10m"
read_batch_size = 128
sync_write = false

• dir: is the directory where to write logs. When using File storage, it’s {data_home}/wal by default. It must be configured explicitly when using other storage types such as S3 etc.
• file_size: the maximum size of the WAL log file, default is 256MB.
• purge_threshold and purge_interval: control the purging of wal files, default is 4GB.
• sync_write: whether to call fsync when writing every log.

Logging options

frontend, metasrv, datanode and standalone can all configure log and tracing related parameters in the [logging] section:

[logging]
dir = "/tmp/greptimedb/logs"
level = "info"
enable_otlp_tracing = false
otlp_endpoint = "localhost:4317"
append_stdout = true
[logging.tracing_sample_ratio]
default_ratio = 1.0

• dir: log output directory.
• level: output log level, available log level are info, debug, error, warn, the default level is info.
• enable_otlp_tracing: whether to turn on tracing, not turned on by default.
• otlp_endpoint: Export the target endpoint of tracing using gRPC-based OTLP protocol, the default value is localhost:4317.
• append_stdout: Whether to append logs to stdout. Defaults to true.
• tracing_sample_ratio: This field can configure the sampling rate of tracing. How to use tracing_sample_ratio, please refer to How to configure tracing sampling rate.

How to use distributed tracing, please reference Tracing

Region engine options

The parameters corresponding to different storage engines can be configured for datanode and standalone in the [region_engine] section. Currently, only options for mito region engine is available.

Frequently used options:

[[region_engine]]
[region_engine.mito]
num_workers = 8
manifest_checkpoint_distance = 10
max_background_jobs = 4
auto_flush_interval = "1h"
global_write_buffer_size = "1GB"
global_write_buffer_reject_size = "2GB"
sst_meta_cache_size = "128MB"
vector_cache_size = "512MB"
page_cache_size = "512MB"
sst_write_buffer_size = "8MB"
scan_parallelism = 0
[region_engine.mito.inverted_index]
create_on_flush = "auto"
create_on_compaction = "auto"
apply_on_query = "auto"
mem_threshold_on_create = "64M"
intermediate_path = ""
[region_engine.mito.memtable]
type = "time_series"

The mito engine provides an experimental memtable which optimizes for write performance and memory efficiency under large amounts of time-series. Its read performance might not as fast as the default time_series memtable.

[region_engine.mito.memtable]
type = "partition_tree"
index_max_keys_per_shard = 8192
data_freeze_threshold = 32768
fork_dictionary_bytes = "1GiB"

Available options:

Specify meta client

The meta_client options are valid in datanode and frontend mode, which specify the Metasrv client information.

metasrv_addrs = ["127.0.0.1:3002"]
timeout = "3s"
connect_timeout = "1s"
ddl_timeout = "10s"
tcp_nodelay = true

The meta_client configures the Metasrv client, including:

• metasrv_addrs: The Metasrv address list.
• timeout: operation timeout, 3s by default.
• connect_timeout, connect server timeout, 1s by default.
• ddl_timeout, DDL execution timeout, 10s by default.
• tcp_nodelay, TCP_NODELAY option for accepted connections, true by default.

Monitor metrics options

These options are used to save system metrics to GreptimeDB itself. For instructions on how to use this feature, please refer to the Monitoring guide.

[export_metrics]
# Whether to enable export_metrics
enable=true
# Export time interval
write_interval = "30s"

• enable: Whether to enable export_metrics, false by default.
• write_interval: Export time interval.

self_import method

Only frontend and standalone support exporting metrics using self_import method.

[export_metrics]
# Whether to enable export_metrics
enable=true
# Export time interval
write_interval = "30s"
[export_metrics.self_import]
db = "information_schema"

• db: The default database used by self_import is information_schema. You can also create another database for saving system metrics.

remote_write method

The remote_write method is supported by datanode, frontend, metasrv, and standalone. It sends metrics to a receiver compatible with the Prometheus Remote-Write protocol.

[export_metrics]
# Whether to enable export_metrics
enable=true
# Export time interval
write_interval = "30s"
[export_metrics.remote_write]
# URL specified by Prometheus Remote-Write protocol
url = "http://127.0.0.1:4000/v1/prometheus/write?db=information_schema"
# Some optional HTTP parameters, such as authentication information
headers = { Authorization = "Basic Z3JlcHRpbWVfdXNlcjpncmVwdGltZV9wd2Q=" }

• url: URL specified by Prometheus Remote-Write protocol.
• headers: Some optional HTTP parameters, such as authentication information.

Mode option

The mode option is valid in datanode, frontend and standalone, which specify the running mode of the component.

In the configuration files of datanode and frontend of distributed GreptimeDB, the value needs to be set as distributed:

mode = "distributed"

In the configuration files of standalone GreptimeDB, the value needs to be set as standalone:

mode = "standalone"

Metasrv-only configuration

# The working home directory.
data_home = "/tmp/metasrv/"
# The bind address of metasrv, "127.0.0.1:3002" by default.
bind_addr = "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.
server_addr = "127.0.0.1:3002"
# Etcd server addresses, "127.0.0.1:2379" by default.
store_addr = "127.0.0.1:2379"
# Datanode selector type.
# - "lease_based" (default value).
# - "load_based"
# For details, please see "https://docs.greptime.com/contributor-guide/meta/selector".
selector = "LeaseBased"
# Store data in memory, false by default.
use_memory_store = false

Datanode-only configuration

node_id = 42
rpc_hostname = "127.0.0.1"
rpc_addr = "127.0.0.1:3001"
rpc_runtime_size = 8

Environment variable

Every item in the configuration file can be mapped into environment variables. For example, if we want to set the configuration item data_home of the datanode by environment variable:

# ...
[storage]
data_home = "/data/greptimedb"
# ...

You can use the following shell command to setup the environment variable as the following format:

export GREPTIMEDB_DATANODE__STORAGE__DATA_HOME=/data/greptimedb

Environment Variable Rules

• Every environment variable should have the component prefix, for example:

  • GREPTIMEDB_FRONTEND
  • GREPTIMEDB_METASRV
  • GREPTIMEDB_DATANODE
  • GREPTIMEDB_STANDALONE
• We use double underscore __ as a separator. For example, the above data structure storage.data_home will be transformed to STORAGE__DATA_HOME.

The environment variable also accepts list that are separated by a comma ,, for example:

GREPTIMEDB_METASRV__META_CLIENT__METASRV_ADDRS=127.0.0.1:3001,127.0.0.1:3002,127.0.0.1:3003