yb-tserver Configuration

The YB-TServer (Tablet Server) is responsible for storing and managing data, processing client requests, and handling replication in a YugabyteDB cluster. Proper configuration is essential for optimizing performance, managing resources, ensuring security, and maintaining high availability.

Overview

The yb-tserver executable is located in the bin directory of your YugabyteDB installation. Each YB-TServer manages tablets (sharded units of storage) and serves both YSQL and YCQL requests.

If you are using YugabyteDB Anywhere, set flags using the Edit Flags feature in the platform UI.

Configuration Categories

Category	Description
General Configuration	Basic server setup, logging, and web interface
PostgreSQL Parameters	YSQL-specific configuration parameters
Networking	Network interfaces, RPC endpoints, DNS caching
Storage & Data Management	Data directories, WAL, sharding, CDC, TTL
Performance Tuning	Resource allocation, memory, compaction
Security	Encryption, SSL/TLS, authentication

Syntax

yb-tserver [flags]

Example

./bin/yb-tserver \
  --tserver_master_addrs 172.151.17.130:7100,172.151.17.220:7100,172.151.17.140:7100 \
  --rpc_bind_addresses 172.151.17.130 \
  --enable_ysql \
  --fs_data_dirs "/home/centos/disk1,/home/centos/disk2"

Online Help

To display command-line help:

./bin/yb-tserver --help

Use --helpon to display help on specific modules:

./bin/yb-tserver --helpon=<module_name>

General Configuration

Core Flags

--flagfile

string

Specifies the file to load configuration flags from. Flags must be in the same format as command line flags.

Requires restart after modification.

--version

flag

Shows version and build information, then exits.

--tserver_master_addrs

string

required

Comma-separated addresses of the masters which the tablet server should connect to. The CQL proxy also reads this flag.Default: 127.0.0.1:7100

This flag is stable and widely used in production.

--tserver_master_replication_factor

uint64

Number of master replicas. By default, detected from tserver_master_addrs, but can be specified explicitly for Kubernetes auto-discovery.Default: 0 (auto-detect)

--max_clock_skew_usec

int64

Expected maximum clock skew in microseconds between any two nodes in the deployment.Default: 500000 (500 ms)

Requires restart after modification.

--tablet_server_svc_queue_length

int32

Queue size for the tablet server to serve reads and writes from applications.Default: 5000

Requires restart after modification.

--time_source

string

Time source used by the database. Set to clockbound for highly accurate time sources.Default: ""

Using clockbound requires additional system configuration for time synchronization.

Web Server Configuration

--webserver_interface

string

Address to bind for the web server user interface.Default: 0.0.0.0 (or 127.0.0.1)

--webserver_port

int32

Port for monitoring the web server.Default: 9000

--webserver_doc_root

string

Monitoring web server home directory.Default: The www directory in YugabyteDB home

--webserver_certificate_file

string

Location of SSL certificate file (in .pem format) for the web server. If empty, SSL is disabled.Default: ""

Requires restart after modification.

--webserver_authentication_domain

string

Domain used for .htpasswd authentication. Use with --webserver_password_file.Default: ""

Requires restart after modification.

--webserver_password_file

string

Location of .htpasswd file containing usernames and hashed passwords for web server authentication.Default: ""

Requires restart after modification.

Logging Flags

--log_dir

string

Directory to write yb-tserver log files.Default: Same as --fs_data_dirs

Requires restart after modification.

--logtostderr

boolean

Write log messages to stderr instead of log files.Default: false

--max_log_size

int32

Maximum log size in megabytes. A value of 0 is silently overridden to 1.Default: 1800 (1.8 GB)

--minloglevel

int32

Minimum level to log messages. Values: 0 (INFO), 1 (WARN), 2 (ERROR), 3 (FATAL).Default: 0 (INFO)

--stderrthreshold

int32

Log messages at or above this level are copied to stderr in addition to log files.Default: 3

--stop_logging_if_full_disk

boolean

Stop attempting to log to disk if the disk is full.Default: false

--callhome_enabled

boolean

Enable or disable callhome diagnostics.Default: true

Networking

--rpc_bind_addresses

string

Comma-separated list of network interface addresses to bind for RPC connections.Default: Private IP of the host (e.g., 172.161.x.x:9100)

Values must match across all yb-tserver and yb-master configurations.

--server_broadcast_addresses

string

Public IP or DNS hostname of the server (with optional port) for server-to-server communication.Default: ""

--dns_cache_expiration_ms

int32

Duration in milliseconds until a cached DNS resolution expires.Default: 60000 (1 minute)

--use_private_ip

string

Policy for using private IP addresses for inter-node communication.Valid values:

never - Always use broadcast addresses
zone - Use private IP within zone
region - Use private IP within region

Default: never

--redis_proxy_bind_address

string

Address to bind the Redis proxy to.Default: ""

--cql_proxy_bind_address

string

Address to bind the CQL proxy to.Default: ""

--pgsql_proxy_bind_address

string

Address to bind the PostgreSQL proxy to.Default: ""

Requires restart after modification.

Storage and Data Management

--fs_data_dirs

string

required

Comma-separated list of mount directories where yb-tserver will create a yb-data/tserver data directory.

Changing this value after cluster creation is not supported.

--fs_wal_dirs

string

Comma-separated list of directories for write-ahead logs (WAL). Can be the same as --fs_data_dirs but not a subdirectory.Default: Same as --fs_data_dirs

--rocksdb_compact_flush_rate_limit_bytes_per_sec

int64

Rate limit for RocksDB compaction and flush operations in bytes per second.Default: 256000000 (256 MB/s)

--rocksdb_block_cache_size_bytes

int64

Size of the RocksDB block cache in bytes. Set to -1 for automatic sizing.Default: -1 (auto)

--db_block_size_bytes

int32

Size of RocksDB data blocks in bytes.Default: 32768 (32 KB)

--tablet_enable_ttl_file_filter

boolean

Enable TTL-based file filtering to improve scan performance on tables with TTL.Default: true

Performance Tuning

Memory Management

--memory_limit_hard_bytes

int64

Maximum memory this process should use in bytes. A value of 0 uses a percentage of total system memory.Default: 0

For Kubernetes, this is automatically set from pod memory limits.

--default_memory_limit_to_ram_ratio

double

Percentage of available RAM to use when --memory_limit_hard_bytes is 0.Default: 0.10 (10%)

Does not apply to Kubernetes deployments.

--use_memory_defaults_optimized_for_ysql

boolean

When true, memory division defaults are optimized for YSQL and account for available RAM and cores.Default: false (set to true with yugabyted)

Compaction Settings

--scheduled_full_compaction_frequency_hours

int32

Frequency in hours for scheduled full compaction. A value of 0 disables scheduled compaction.Default: 0 (disabled)

--auto_compact_percent_obsolete

double

Percentage of obsolete keys required to trigger automatic compaction.Default: 99

--auto_compact_min_obsolete_keys_found

uint32

Minimum number of obsolete keys required to trigger automatic compaction.Default: 10000

--auto_compact_min_wait_between_seconds

uint32

Minimum wait time in seconds between automatic compactions.Default: 0

Heartbeat Configuration

--heartbeat_interval_ms

int32

Interval in milliseconds between heartbeats sent to the master.Default: 1000 (1 second)

--heartbeat_rpc_timeout_ms

int32

Timeout in milliseconds for heartbeat RPC operations.Default: 15000 (15 seconds)

--heartbeat_max_failures_before_backoff

int32

Number of consecutive heartbeat failures before backing off.Default: 3

PostgreSQL Configuration Parameters

YugabyteDB uses PostgreSQL server configuration parameters for YSQL. You can modify these parameters using several methods, listed in order of precedence (lowest to highest):

PostgreSQL server configuration flag (--ysql_pg_conf_csv)
```
--ysql_pg_conf_csv=yb_bnl_batch_size=512
```
Direct YSQL flag (if available with ysql_ prefix)
```
--ysql_yb_bnl_batch_size=512
```

Per-database setting

ALTER DATABASE database_name SET yb_bnl_batch_size=512;

Per-role setting

ALTER ROLE yugabyte SET yb_bnl_batch_size=512;

Per-session setting
```
SET yb_bnl_batch_size=512;
```
Per-transaction setting
```
SET LOCAL yb_bnl_batch_size=512;
```

--ysql_pg_conf_csv

string

Comma-separated list of PostgreSQL configuration parameters in key=value format.Example: --ysql_pg_conf_csv="max_connections=200,shared_buffers=2GB"

--enable_ysql

boolean

Enable the YSQL API.Default: true

Must match the value on all yb-master servers.

--ysql_enable_auth

boolean

Enable YSQL authentication.Default: false

--ysql_hba_conf_csv

string

Comma-separated list of PostgreSQL host-based authentication rules.

Security

--use_client_to_server_encryption

boolean

Enable SSL/TLS encryption for client-to-server communications.Default: false

--use_node_to_node_encryption

boolean

Enable SSL/TLS encryption for node-to-node communications.Default: false

--certs_dir

string

Directory containing SSL certificate and key files.Default: ""

--allow_insecure_connections

boolean

Allow insecure connections when encryption is enabled.Default: true

--enable_ysql_conn_mgr

boolean

Enable the YSQL connection manager for connection pooling.Default: false

Requires restart after modification.

--ysql_conn_mgr_port

uint32

Port for the YSQL connection manager.Default: 5433

Metrics and Monitoring

--metrics_snapshotter_interval_ms

int32

Interval in milliseconds for metrics snapshots.Default: 30000 (30 seconds)

--export_help_and_type_in_prometheus_metrics

boolean

Include #TYPE and #HELP information in Prometheus metrics output.Default: true

--max_prometheus_metric_entries

uint32

Maximum number of Prometheus metric entries returned per scrape.Default: UINT32_MAX

--export_intentdb_metrics

boolean

Export IntentsDB statistics to Prometheus metrics.Default: true

Advanced Flags

--use_tablespace_based_transaction_placement

boolean

Use tablespace-based placement for transaction status tables.Default: false

--report_ysql_ddl_txn_status_to_master

boolean

Report YSQL DDL transaction status to master.Default: true

--pg_client_session_expiration_ms

uint64

PostgreSQL client session expiration time in milliseconds.Default: 60000 (1 minute)

Configuration

System Tables

yb-tserver Configuration

Overview

Configuration Categories

Syntax

Example

Online Help

General Configuration

Core Flags

Web Server Configuration

Logging Flags

Networking

Storage and Data Management

Performance Tuning

Memory Management

Compaction Settings

Heartbeat Configuration

PostgreSQL Configuration Parameters

Security

Metrics and Monitoring

Advanced Flags

See Also

Build docs developers (and LLMs) love

Configuration

System Tables

​Overview

​Configuration Categories

​Syntax

​Example

​Online Help

​General Configuration

​Core Flags

​Web Server Configuration

​Logging Flags

​Networking

​Storage and Data Management

​Performance Tuning

​Memory Management

​Compaction Settings

​Heartbeat Configuration

​PostgreSQL Configuration Parameters

​Security

​Metrics and Monitoring

​Advanced Flags

​See Also

Build docs developers (and LLMs) love

Overview

Configuration Categories

Syntax

Example

Online Help

General Configuration

Core Flags

Web Server Configuration

Logging Flags

Networking

Storage and Data Management

Performance Tuning

Memory Management

Compaction Settings

Heartbeat Configuration

PostgreSQL Configuration Parameters

Security

Metrics and Monitoring

Advanced Flags

See Also