vttablet

A VTTablet server controls a running MySQL server. VTTablet supports two primary types of deployments:

  • Managed MySQL (most common)
  • External MySQL

In addition to these deployment types, a partially managed VTTablet is also possible by setting --disable_active_reparents.

Example Usage #

Managed MySQL #

In this mode, Vitess actively manages MySQL:

export TOPOLOGY_FLAGS="--topo_implementation etcd2 --topo_global_server_address localhost:2379 --topo_global_root /vitess/global"
export VTDATAROOT="/tmp"

vttablet \
$TOPOLOGY_FLAGS
--tablet-path $alias
--init_keyspace $keyspace
--init_shard $shard
--init_tablet_type $tablet_type
--port $port
--grpc_port $grpc_port
--service_map 'grpc-queryservice,grpc-tabletmanager,grpc-updatestream'

$alias needs to be of the form: <cell>-id, and the cell should match one of the local cells that was created in the topology. The id can be left padded with zeroes: cell-100 and cell-000000100 are synonymous.

External MySQL #

In this mode, an external MySQL can be used such as AWS RDS, AWS Aurora, Google CloudSQL; or just an existing (vanilla) MySQL installation.

See Unmanaged Tablet for the full guide.

Even if a MySQL is external, you can still make vttablet perform some management functions. They are as follows:

  • --disable_active_reparents: If this flag is set, then any reparent or replica commands will not be allowed. These are InitShardPrimary, PlannedReparentShard, EmergencyReparentShard, and ReparentTablet. In this mode, you should use the TabletExternallyReparented command to inform vitess of the current primary.
  • --replication_connect_retry: This value is give to mysql when it connects a replica to the primary as the retry duration parameter.
  • --enable_replication_reporter: If this flag is set, then vttablet will transmit replica lag related information to the vtgates, which will allow it to balance load better. Additionally, enabling this will also cause vttablet to restart replication if it was stopped. However, it will do this only if --disable_active_reparents was not turned on.
  • --enable_semi_sync: This option will automatically enable semi-sync on new replicas as well as on any tablet that transitions into a replica type. This includes the demotion of a primary to a replica.
  • --heartbeat_enable and --heartbeat interval duration: cause vttablet to write heartbeats to the sidecar database. This information is also used by the replication reporter to assess replica lag.

Options #

The following global options apply to vttablet:

NameTypeDefinition
--alsologtostderrbooleanlog to standard error as well as files
--app_idle_timeoutdurationIdle timeout for app connections (default 1m0s)
--app_pool_sizeintSize of the connection pool for app connections (default 40)
--azblob_backup_account_key_filestringPath to a file containing the Azure Storage account key; if this flag is unset, the environment variable VT_AZBLOB_ACCOUNT_KEY will be used as the key itself (NOT a file path)
--azblob_backup_account_namestringAzure Storage Account name for backups; if this flag is unset, the environment variable VT_AZBLOB_ACCOUNT_NAME will be used
--azblob_backup_container_namestringAzure Blob Container Name
--azblob_backup_parallelismintAzure Blob operation parallelism (requires extra memory when increased) (default 1)
--azblob_backup_storage_rootstringRoot prefix for all backup-related Azure Blobs; this should exclude both initial and trailing '/' (e.g. just 'a/b' not '/a/b/')
--backup_engine_implementationstringSpecifies which implementation to use for creating new backups (builtin or xtrabackup). Restores will always be done with whichever engine created a given backup. (default "builtin")
--backup_storage_block_sizeintif backup_storage_compress is true, backup_storage_block_size sets the byte size for each block while compressing (default is 250000). (default 250000)
--backup_storage_compressif set, the backup files will be compressed (default is true). Set to false for instance if a backup_storage_hook is specified and it compresses the data. (default true)
--backup_storage_hookstringif set, we send the contents of the backup files through this hook.
--backup_storage_implementationstringwhich implementation to use for the backup storage feature
--backup_storage_number_blocksintif backup_storage_compress is true, backup_storage_number_blocks sets the number of blocks that can be processed, at once, before the writer blocks, during compression (default is 2). It should be equal to the number of CPUs available for compression (default 2)
--binlog_player_grpc_castringthe server ca to use to validate servers when connecting
--binlog_player_grpc_certstringthe cert to use to connect
--binlog_player_grpc_keystringthe key to use to connect
--binlog_player_grpc_server_namestringthe server name to use to validate server certificate
--binlog_player_protocolstringthe protocol to download binlogs from a vttablet (default "grpc")
--binlog_use_v3_resharding_modeTrue iff the binlog streamer should use V3-style sharding, which doesn't require a preset sharding key column. (default true)
--ceph_backup_storage_configstringPath to JSON config file for ceph backup storage (default "ceph_backup_config.json")
--consul_auth_static_filestringJSON File to read the topos/tokens from.
--cpu_profilestringwrite cpu profile to file
--datadog-agent-hoststringhost to send spans to. if empty, no tracing will be done
--datadog-agent-portstringport to send spans to. if empty, no tracing will be done
--db-credentials-filestringdb credentials file; send SIGHUP to reload this file
--db-credentials-serverstringdb credentials server type (use 'file' for the file implementation) (default "file")
--db_allprivs_passwordstringdb allprivs password
--db_allprivs_use_sslSet this flag to false to make the allprivs connection to not use SSL (default true)
--db_allprivs_userstringdb allprivs user userKey (default "vt_allprivs")
--db_app_passwordstringdb app password
--db_app_use_sslSet this flag to false to make the app connection to not use SSL (default true)
--db_app_userstringdb app user userKey. Used for VReplication. (default "vt_app")
--db_appdebug_passwordstringdb appdebug password
--db_appdebug_use_sslSet this flag to false to make the appdebug connection to not use SSL (default true)
--db_appdebug_userstringdb appdebug user userKey (default "vt_appdebug")
--db_charsetstringSets the character set for the connection.
--db_connect_timeout_msintconnection timeout to mysqld in milliseconds (0 for no timeout)
--db_dba_passwordstringdb dba password
--db_dba_use_sslSet this flag to false to make the dba connection to not use SSL (default true)
--db_dba_userstringdb dba user userKey (default "vt_dba")
--db_erepl_passwordstringdb erepl password
--db_erepl_use_sslSet this flag to false to make the erepl connection to not use SSL (default true)
--db_erepl_userstringdb erepl user userKey (default "vt_erepl")
--db_filtered_passwordstringdb filtered password
--db_filtered_use_sslSet this flag to false to make the filtered connection to not use SSL (default true)
--db_filtered_userstringdb filtered user userKey (default "vt_filtered")
--db_flagsuintFlag values as defined by MySQL.
--db_flavorstringFlavor overrid. Valid value is FilePos.
--db_hoststringThe host name for the tcp connection.
--db_portinttcp port
--db_repl_passwordstringdb repl password
--db_repl_use_sslSet this flag to false to make the repl connection to not use SSL (default true)
--db_repl_userstringdb repl user userKey (default "vt_repl")
--db_server_namestringserver name of the DB we are connecting to.
--db_socketstringThe unix socket to connect on. If this is specified, host and port will not be used.
--db_ssl_castringconnection SSL ca
--db_ssl_ca_pathstringconnection SSL ca path
--db_ssl_certstringconnection SSL certificate
--db_ssl_keystringconnection SSL key
--db_tls_min_versionstringConfigures the minimal TLS version negotiated when SSL is enabled. Defaults to TLSv1.2. Options: TLSv1.0, TLSv1.1, TLSv1.2, TLSv1.3
--dba_idle_timeoutdurationIdle timeout for dba connections (default 1m0s)
--dba_pool_sizeintSize of the connection pool for dba connections (default 20)
--degraded_thresholddurationreplication lag after which a replica is considered degraded (only used in status UI) (default 30s)
--disable_active_reparentsif set, do not allow active reparents. Use this to protect a cluster using external reparents.
--discovery_high_replication_lag_minimum_servingdurationthe replication lag that is considered too high when selecting the minimum num vttablets for serving (default 2h0m0s)
--discovery_low_replication_lagdurationthe replication lag that is considered low enough to be healthy (default 30s)
--emit_statstrue iff we should emit stats to push-based monitoring/stats backends
--enable-consolidatorThis option enables the query consolidator. (default true)
--enable-consolidator-replicasThis option enables the query consolidator only on replicas.
--enable-query-plan-field-cachingThis option fetches & caches fields (columns) when storing query plans (default true)
--enable-tx-throttlerIf true replication-lag-based throttling on transactions will be enabled.
--enable_hot_row_protectionIf true, incoming transactions for the same row (range) will be queued and cannot consume all txpool slots.
--enable_hot_row_protection_dry_runIf true, hot row protection is not enforced but logs if transactions would have been queued.
--enable_replication_reporterRegister the health check module that monitors MySQL replication
--enable_semi_syncEnable semi-sync when configuring replication, on primary and replica tablets only (rdonly tablets will not ack).
--enable_transaction_limitIf true, limit on number of transactions open at the same time will be enforced for all users. User trying to open a new transaction after exhausting their limit will receive an error immediately, regardless of whether there are available slots or not.
--enable_transaction_limit_dry_runIf true, limit on number of transactions open at the same time will be tracked for all users, but not enforced.
--enforce-tableacl-configif this flag is true, vttablet will fail to start if a valid tableacl config does not exist
--enforce_strict_trans_tablesIf true, vttablet requires MySQL to run with STRICT_TRANS_TABLES or STRICT_ALL_TABLES on. It is recommended to not turn this flag off. Otherwise MySQL may alter your supplied values before saving them to the database. (default true)
--file_backup_storage_rootstringroot directory for the file backup storage -- this path must be on shared storage to provide a global view of backups to all vitess components
--filecustomrulesstringfile based custom rule path
--finalize_external_reparent_timeoutdurationTimeout for the finalize stage of a fast external reparent reconciliation. (default 30s)
--gcs_backup_storage_bucketstringGoogle Cloud Storage bucket to use for backups
--gcs_backup_storage_rootstringroot prefix for all backup-related object names
--grpc_auth_modestringWhich auth plugin implementation to use (eg: static)
--grpc_auth_mtls_allowed_substringsstringList of substrings of at least one of the client certificate names (separated by colon).
--grpc_auth_static_client_credsstringwhen using grpc_static_auth in the server, this file provides the credentials to use to authenticate with server
--grpc_auth_static_password_filestringJSON File to read the users/passwords from.
--grpc_castringca to use, requires TLS, and enforces client cert check
--grpc_certstringcertificate to use, requires grpc_key, enables TLS
--grpc_compressionstringhow to compress gRPC, default: nothing, supported: snappy
--grpc_enable_tracingEnable GRPC tracing
--grpc_initial_conn_window_sizeintgrpc initial connection window size
--grpc_initial_window_sizeintgrpc initial window size
--grpc_keepalive_timedurationAfter a duration of this time if the client doesn't see any activity it pings the server to see if the transport is still alive. (default 10s)
--grpc_keepalive_timeoutdurationAfter having pinged for keepalive check, the client waits for a duration of Timeout and if no activity is seen even after that the connection is closed. (default 10s)
--grpc_keystringkey to use, requires grpc_cert, enables TLS
--grpc_max_connection_agedurationMaximum age of a client connection before GoAway is sent. (default 2562047h47m16.854775807s)
--grpc_max_connection_age_gracedurationAdditional grace period after grpc_max_connection_age, after which connections are forcibly closed. (default 2562047h47m16.854775807s)
--grpc_max_message_sizeintMaximum allowed RPC message size. Larger messages will be rejected by gRPC with the error 'exceeding the max size'. (default 16777216)
--grpc_portintPort to listen on for gRPC calls
--grpc_prometheusEnable gRPC monitoring with Prometheus
--grpc_server_initial_conn_window_sizeintgrpc server initial connection window size
--grpc_server_initial_window_sizeintgrpc server initial window size
--grpc_server_keepalive_enforcement_policy_min_timedurationgrpc server minimum keepalive time (default 5m0s)
--grpc_server_keepalive_enforcement_policy_permit_without_streamgrpc server permit client keepalive pings even when there are no active streams (RPCs)
--health_check_intervaldurationInterval between health checks (default 20s)
--heartbeat_enableIf true, vttablet records (if primary) or checks (if replica) the current time of a replication heartbeat in the table _vt.heartbeat. The result is used to inform the serving state of the vttablet via healthchecks.
--heartbeat_intervaldurationHow frequently to read and write replication heartbeat. (default 1s)
--hot_row_protection_concurrent_transactionsintNumber of concurrent transactions let through to the txpool/MySQL for the same hot row. Should be > 1 to have enough 'ready' transactions in MySQL and benefit from a pipelining effect. (default 5)
--hot_row_protection_max_global_queue_sizeintGlobal queue limit across all row (ranges). Useful to prevent that the queue can grow unbounded. (default 1000)
--hot_row_protection_max_queue_sizeintMaximum number of BeginExecute RPCs which will be queued for the same row (range). (default 20)
--init_db_name_overridestring(init parameter) override the name of the db used by vttablet. Without this flag, the db name defaults to vt_
--init_keyspacestring(init parameter) keyspace to use for this tablet
--init_populate_metadata(init parameter) populate metadata tables even if restore_from_backup is disabled. If restore_from_backup is enabled, metadata tables are always populated regardless of this flag.
--init_shardstring(init parameter) shard to use for this tablet
--init_tablet_typestring(init parameter) the tablet type to use for this tablet.
--init_tagsvalue(init parameter) comma separated list of key:value pairs used to tag the tablet
--init_timeoutduration(init parameter) timeout to use for the init phase. (default 1m0s)
--jaeger-agent-hoststringhost and port to send spans to. If empty, no tracing will be done
--keep_logsdurationkeep logs for this long (using ctime) (zero to keep forever). Note ctime here means "change time" and can be essentially equivalent to mtime. Read #5318
--keep_logs_by_mtimedurationkeep logs for this long (using mtime) (zero to keep forever)
--lameduck-perioddurationkeep running at least this long after SIGTERM before stopping (default 50ms)
--legacy_replication_lag_algorithmuse the legacy algorithm when selecting the vttablets for serving (default true)
--lock_tables_timeoutdurationHow long to keep the table locked before timing out (default 1m0s)
--log_backtrace_atvaluewhen logging hits line file:N, emit a stack trace
--log_dirstringIf non-empty, write log files in this directory
--log_err_stackslog stack traces for errors
--log_queriesEnable query logging to syslog.
--log_queries_to_filestringEnable query logging to the specified file
--log_rotate_max_sizeuintsize in bytes at which logs are rotated (glog.MaxSize) (default 1887436800)
--logtostderrlog to standard error instead of files
--replication_connect_retrydurationhow long to wait in between replica reconnect attempts. Only precise to the second. (default 10s)
--mem-profile-rateintprofile every n bytes allocated (default 524288)
--min_number_serving_vttabletsintthe minimum number of vttablets that will be continue to be used even with low replication lag (default 2)
--mutex-profile-fractionintprofile every n mutex contention events (see runtime.SetMutexProfileFraction)
--mycnf-filestringpath to my.cnf, if reading all config params from there
--mycnf_bin_log_pathstringmysql binlog path
--mycnf_data_dirstringdata directory for mysql
--mycnf_error_log_pathstringmysql error log path
--mycnf_general_log_pathstringmysql general log path
--mycnf_innodb_data_home_dirstringInnodb data home directory
--mycnf_innodb_log_group_home_dirstringInnodb log group home directory
--mycnf_master_info_filestringmysql master.info file
--mycnf_mysql_portintport mysql is listening on
--mycnf_pid_filestringmysql pid file
--mycnf_relay_log_index_pathstringmysql relay log index path
--mycnf_relay_log_info_pathstringmysql relay log info path
--mycnf_relay_log_pathstringmysql relay log path
--mycnf_server_idintmysql server id of the server (if specified, mycnf-file will be ignored)
--mycnf_slow_log_pathstringmysql slow query log path
--mycnf_socket_filestringmysql socket file
--mycnf_tmp_dirstringmysql tmp directory
--mysql_auth_server_static_filestringJSON File to read the users/passwords from.
--mysql_auth_server_static_stringstringJSON representation of the users/passwords config.
--mysql_auth_static_reload_intervaldurationTicker to reload credentials
--mysql_clientcert_auth_methodstringclient-side authentication method to use. Supported values: mysql_clear_password, dialog. (default "mysql_clear_password")
--mysql_server_flush_delaydurationDelay after which buffered response will flushed to client. (default 100ms)
--mysql_server_versionstringMySQL server version to advertise.
--mysqlctl_client_protocolstringthe protocol to use to talk to the mysqlctl server (default "grpc")
--mysqlctl_mycnf_templatestringtemplate file to use for generating the my.cnf file during server init
--mysqlctl_socketstringsocket file to use for remote mysqlctl actions (empty for local actions)
--onterm_timeoutdurationwait no more than this for OnTermSync handlers before stopping (default 10s)
--opentsdb_uristringURI of opentsdb /api/put method
--orc_api_passwordstring(Optional) Basic auth password to authenticate with Orchestrator's HTTP API.
--orc_api_urlstringAddress of Orchestrator's HTTP API (e.g. http://host:port/api/). Leave empty to disable Orchestrator integration.
--orc_api_userstring(Optional) Basic auth username to authenticate with Orchestrator's HTTP API. Leave empty to disable basic auth.
--orc_discover_intervaldurationHow often to ping Orchestrator's HTTP API endpoint to tell it we exist. 0 means never.
--orc_timeoutdurationTimeout for calls to Orchestrator's HTTP API (default 30s)
--pid_filestringIf set, the process will write its pid to the named file, and delete it on graceful shutdown.
--pool_hostname_resolve_intervaldurationif set force an update to all hostnames and reconnect if changed, defaults to 0 (disabled)
--portintport for the server
--purge_logs_intervaldurationhow often try to remove old logs (default 1h0m0s)
--query-log-stream-handlerstringURL handler for streaming queries log (default "/debug/querylog")
--querylog-filter-tagstringstring that must be present in the query as a comment for the query to be logged, works for both vtgate and vttablet
--querylog-formatstringformat for query logs ("text" or "json") (default "text")
--queryserver-config-acl-exempt-aclstringan acl that exempt from table acl checking (this acl is free to access any vitess tables).
--queryserver-config-enable-table-acl-dry-runIf this flag is enabled, tabletserver will emit monitoring metrics and let the request pass regardless of table acl check results
--queryserver-config-idle-timeoutintquery server idle timeout (in seconds), vttablet manages various mysql connection pools. This config means if a connection has not been used in given idle timeout, this connection will be removed from pool. This effectively manages number of connection objects and optimize the pool performance. (default 1800)
--queryserver-config-max-dml-rowsintquery server max dml rows per statement, maximum number of rows allowed to return at a time for an update or delete with either 1) an equality where clauses on primary keys, or 2) a subselect statement. For update and delete statements in above two categories, vttablet will split the original query into multiple small queries based on this configuration value.
--queryserver-config-max-result-sizeintquery server max result size, maximum number of rows allowed to return from vttablet for non-streaming queries. (default 10000)
--queryserver-config-message-postpone-capintquery server message postpone cap is the maximum number of messages that can be postponed at any given time. Set this number to substantially lower than transaction cap, so that the transaction pool isn't exhausted by the message subsystem. (default 4)
--queryserver-config-passthrough-dmlsquery server pass through all dml statements without rewriting
--queryserver-config-pool-prefill-parallelismintquery server read pool prefill parallelism, a non-zero value will prefill the pool using the specified parallism.
--queryserver-config-pool-sizeintquery server read pool size, connection pool is used by regular queries (non streaming, not in a transaction) (default 16)
--queryserver-config-query-cache-sizeintquery server query cache size, maximum number of queries to be cached. vttablet analyzes every incoming query and generate a query plan, these plans are being cached in a lru cache. This config controls the capacity of the lru cache. (default 5000)
--queryserver-config-query-pool-timeoutintquery server query pool timeout (in seconds), it is how long vttablet waits for a connection from the query pool. If set to 0 (default) then the overall query timeout is used instead.
--queryserver-config-query-pool-waiter-capintquery server query pool waiter limit, this is the maximum number of queries that can be queued waiting to get a connection (default 5000)
--queryserver-config-query-timeoutintquery server query timeout (in seconds), this is the query timeout in vttablet side. If a query takes more than this timeout, it will be killed. (default 30)
--queryserver-config-schema-reload-timeintquery server schema reload time, how often vttablet reloads schemas from underlying MySQL instance in seconds. vttablet keeps table schemas in its own memory and periodically refreshes it from MySQL. This config controls the reload time. (default 1800)
--queryserver-config-schema-change-signal-intervalintinterval used to periodically send schema change updates to vtgate (default 5 seconds)
--queryserver-config-schema-change-signalbooleanenable schema tracking
--queryserver-config-stream-buffer-sizeintquery server stream buffer size, the maximum number of bytes sent from vttablet for each stream call. It's recommended to keep this value in sync with vtgate's stream_buffer_size. (default 32768)
--queryserver-config-stream-pool-prefill-parallelismintquery server stream pool prefill parallelism, a non-zero value will prefill the pool using the specified parallelism
--queryserver-config-stream-pool-sizeintquery server stream connection pool size, stream pool is used by stream queries: queries that return results to client in a streaming fashion (default 200)
--queryserver-config-stream-pool-waiter-capintquery server stream pool waiter limit, this is the maximum number of streaming queries that can be queued waiting to get a connection (default unlimited)
--queryserver-config-strict-table-aclonly allow queries that pass table acl checks
--queryserver-config-terse-errorsprevent bind vars from escaping in client error messages
--queryserver-config-transaction-capintquery server transaction cap is the maximum number of transactions allowed to happen at any given point of a time for a single vttablet. E.g. by setting transaction cap to 100, there are at most 100 transactions will be processed by a vttablet and the 101th transaction will be blocked (and fail if it cannot get connection within specified timeout) (default 20)
--queryserver-config-transaction-prefill-parallelismintquery server transaction prefill parallelism, a non-zero value will prefill the pool using the specified parallism.
--queryserver-config-transaction-timeoutintquery server transaction timeout (in seconds), a transaction will be killed if it takes longer than this value (default 30)
--queryserver-config-txpool-timeoutintquery server transaction pool timeout, it is how long vttablet waits if tx pool is full (default 1)
--queryserver-config-txpool-waiter-capintquery server transaction pool waiter limit, this is the maximum number of transactions that can be queued waiting to get a connection (default 5000)
--queryserver-config-warn-result-sizeintquery server result size warning threshold, warn if number of rows returned from vttablet for non-streaming queries exceeds this
--redact-debug-ui-queriesredact full queries and bind variables from debug UI
--remote_operation_timeoutdurationtime to wait for a remote operation (default 30s)
--restore_concurrencyint(init restore parameter) how many concurrent files to restore at once (default 4)
--restore_from_backup(init restore parameter) will check BackupStorage for a recent backup at startup and start there
--restore_from_backup_tsstring(init restore parameter) if set, restore the latest backup taken at or before this timestamp. Example: '2021-04-29.133050' (Vitess 12.0+)
--s3_backup_aws_endpointstringendpoint of the S3 backend (region must be provided)
--s3_backup_aws_regionstringAWS region to use (default "us-east-1")
--s3_backup_aws_retriesintAWS request retries (default -1)
--s3_backup_force_path_styleforce the s3 path style
--s3_backup_log_levelstringdetermine the S3 loglevel to use from LogOff, LogDebug, LogDebugWithSigning, LogDebugWithHTTPBody, LogDebugWithRequestRetries, LogDebugWithRequestErrors (default "LogOff")
--s3_backup_server_side_encryptionstringserver-side encryption algorithm (e.g., AES256, aws:kms)
--s3_backup_storage_bucketstringS3 bucket to use for backups
--s3_backup_storage_rootstringroot prefix for all backup-related object names
--s3_backup_tls_skip_verify_certskip the 'certificate is valid' check for SSL connections
--sanitize_log_messagesboolRemove potentially sensitive information in tablet INFO, WARNING, and ERROR log messages such as query parameters
--security_policystringthe name of a registered security policy to use for controlling access to URLs - empty means allow all for anyone (built-in policies: deny-all, read-only)
--service_mapvaluecomma separated list of services to enable (or disable if prefixed with '-') Example: grpc-queryservice
--serving_state_grace_perioddurationhow long to pause after broadcasting health to vtgate, before enforcing a new serving state
--shard_sync_retry_delaydurationdelay between retries of updates to keep the tablet and its shard record in sync (default 30s)
--sql-max-length-errorsinttruncate queries in error logs to the given length (default unlimited)
--sql-max-length-uiinttruncate queries in debug UIs to the given length (default 512) (default 512)
--srv_topo_cache_refreshdurationhow frequently to refresh the topology for cached entries (default 1s)
--srv_topo_cache_ttldurationhow long to use cached entries for topology (default 1s)
--stats_backendstringThe name of the registered push-based monitoring/stats backend to use
--stats_combine_dimensionsstringList of dimensions to be combined into a single "all" value in exported stats vars
--stats_drop_variablesstringVariables to be dropped from the list of exported variables.
--stats_emit_perioddurationInterval between emitting stats to all registered backends (default 1m0s)
--stderrthresholdvaluelogs at or above this threshold go to stderr (default 1)
--table-acl-configstringpath to table access checker config file; send SIGHUP to reload this file
--table-acl-config-reload-intervaldurationTicker to reload ACLs
--tablet-pathstringtablet alias
--tablet_configstringYAML file config for tablet
--tablet_dirstringThe directory within the vtdataroot to store vttablet/mysql files. Defaults to being generated by the tablet uid.
--tablet_grpc_castringthe server ca to use to validate servers when connecting
--tablet_grpc_certstringthe cert to use to connect
--tablet_grpc_keystringthe key to use to connect
--tablet_grpc_server_namestringthe server name to use to validate server certificate
--tablet_hostnamestringif not empty, this hostname will be assumed instead of trying to resolve it
--tablet_manager_grpc_castringthe server ca to use to validate servers when connecting
--tablet_manager_grpc_certstringthe cert to use to connect
--tablet_manager_grpc_concurrencyintconcurrency to use to talk to a vttablet server for performance-sensitive RPCs (like ExecuteFetchAs{Dba,AllPrivs,App}) (default 8)
--tablet_manager_grpc_keystringthe key to use to connect
--tablet_manager_grpc_server_namestringthe server name to use to validate server certificate
--tablet_manager_protocolstringthe protocol to use to talk to vttablet (default "grpc")
--tablet_protocolstringhow to talk to the vttablets (default "grpc")
--tablet_url_templatestringformat string describing debug tablet url formatting. See the Go code for getTabletDebugURL() how to customize this. (default "http://{{.GetTabletHostPort}}")
--topo_consul_watch_poll_durationdurationtime of the long poll for watch queries. (default 30s)
--topo_etcd_lease_ttlintLease TTL for locks and leader election. The client will use KeepAlive to keep the lease going. (default 30)
--topo_etcd_tls_castringpath to the ca to use to validate the server cert when connecting to the etcd topo server
--topo_etcd_tls_certstringpath to the client cert to use to connect to the etcd topo server, requires topo_etcd_tls_key, enables TLS
--topo_etcd_tls_keystringpath to the client key to use to connect to the etcd topo server, enables TLS
--topo_global_rootstringthe path of the global topology data in the global topology server
--topo_global_server_addressstringthe address of the global topology server
--topo_implementationstringthe topology implementation to use
--topo_k8s_contextstringThe kubeconfig context to use, overrides the 'current-context' from the config
--topo_k8s_kubeconfigstringPath to a valid kubeconfig file.
--topo_k8s_namespacestringThe kubernetes namespace to use for all objects. Default comes from the context or in-cluster config
--topo_zk_auth_filestringauth to use when connecting to the zk topo server, file contents should be :, e.g., digest:user:pass
--topo_zk_base_timeoutdurationzk base timeout (see zk.Connect) (default 30s)
--topo_zk_max_concurrencyintmaximum number of pending requests to send to a Zookeeper server. (default 64)
--topo_zk_tls_castringthe server ca to use to validate servers when connecting to the zk topo server
--topo_zk_tls_certstringthe cert to use to connect to the zk topo server, requires topo_zk_tls_key, enables TLS
--topo_zk_tls_keystringthe key to use to connect to the zk topo server, enables TLS
--topocustomrule_cellstringtopo cell for customrules file. (default "global")
--topocustomrule_pathstringpath for customrules file. Disabled if empty.
--tracerstringtracing service to use (default "noop")
--tracing-sampling-ratefloatsampling rate for the probabilistic jaeger sampler (default 0.1)
--transaction-log-stream-handlerstringURL handler for streaming transactions log (default "/debug/txlog")
--transaction_limit_by_componentInclude CallerID.component when considering who the user is for the purpose of transaction limit.
--transaction_limit_by_principalInclude CallerID.principal when considering who the user is for the purpose of transaction limit. (default true)
--transaction_limit_by_subcomponentInclude CallerID.subcomponent when considering who the user is for the purpose of transaction limit.
--transaction_limit_by_usernameInclude VTGateCallerID.username when considering who the user is for the purpose of transaction limit. (default true)
--transaction_limit_per_userfloatMaximum number of transactions a single user is allowed to use at any time, represented as fraction of --transaction_cap. (default 0.4)
--shutdown_grace_periodfloathow long to wait (in seconds) for queries and transactions to complete during graceful shutdown.
--twopc_abandon_agefloattime in seconds. Any unresolved transaction older than this time will be sent to the coordinator to be resolved.
--twopc_coordinator_addressstringaddress of the (VTGate) process(es) that will be used to notify of abandoned transactions.
--twopc_enableif the flag is on, 2pc is enabled. Other 2pc flags must be supplied.
--tx-throttler-configstringThe configuration of the transaction throttler as a text formatted throttlerdata.Configuration protocol buffer message (default "target_replication_lag_sec: 2 max_replication_lag_sec: 10 initial_rate: 100 max_increase: 1 emergency_decrease: 0.5 min_duration_between_increases_sec: 40 max_duration_between_increases_sec: 62 min_duration_between_decreases_sec: 20 spread_backlog_across_sec: 20 age_bad_rate_after_sec: 180 bad_rate_increase: 0.1 max_rate_approach_threshold: 0.9 ")
--tx-throttler-healthcheck-cellsvalueA comma-separated list of cells. Only tabletservers running in these cells will be monitored for replication lag by the transaction throttler.
--unhealthy_thresholddurationreplication lag after which a replica is considered unhealthy (default 2h0m0s)
--use_super_read_onlySet super_read_only flag when performing planned failover.
-vvaluelog level for V logs
--versionprint binary version
--vmodulevaluecomma-separated list of pattern=N settings for file-filtered logging
--vreplication_copy_phase_durationdurationDuration for each copy phase loop (before running the next catchup: default 1h) (default 1h0m0s)
--vreplication_copy_phase_max_innodb_history_list_lengthintThe maximum InnoDB transaction history that can exist on a vstreamer (source) before starting another round of copying rows. This helps to limit the impact on the source tablet. (default 1000000)
--vreplication_copy_phase_max_mysql_replication_lagintThe maximum MySQL replication lag (in seconds) that can exist on a vstreamer (source) before starting another round of copying rows. This helps to limit the impact on the source tablet. (default 43200)
--vreplication_healthcheck_retry_delaydurationhealthcheck retry delay (default 5s)
--vreplication_healthcheck_timeoutdurationhealthcheck retry delay (default 1m0s)
--vreplication_healthcheck_topology_refreshdurationrefresh interval for re-reading the topology (default 30s)
--vreplication_max_time_to_retry_on_errordurationstop automatically retrying when we've had consecutive failures with the same error for this long after the first occurrence (default 0, unlimited)
--vreplication_retry_delaydurationdelay before retrying a failed binlog connection (default 5s)
--vreplication_tablet_typestringcomma separated list of tablet types used as a source (default "in_order:REPLICA,PRIMARY")
--vstream_packet_sizeintSuggested packet size for VReplication streamer. This is used only as a recommendation. The actual packet size may be more or less than this amount. (default 30000)
--vtctld_addrstringaddress of a vtctld instance
--vtgate_protocolstringhow to talk to vtgate (default "grpc")
--wait_for_backup_intervalduration(init restore parameter) if this is greater than 0, instead of starting up empty when no backups are found, keep checking at this interval for a backup to appear
--watch_replication_streamWhen enabled, vttablet will stream the MySQL replication stream from the local server, and use it to support the include_event_token ExecuteOptions.
--xbstream_restore_flagsstringflags to pass to xbstream command during restore. These should be space separated and will be added to the end of the command. These need to match the ones used for backup e.g. --compress / --decompress, --encrypt / --decrypt
--xtrabackup_backup_flagsstringflags to pass to backup command. These should be space separated and will be added to the end of the command
--xtrabackup_prepare_flagsstringflags to pass to prepare command. These should be space separated and will be added to the end of the command
--xtrabackup_root_pathstringdirectory location of the xtrabackup executable, e.g., /usr/bin
--xtrabackup_stream_modestringwhich mode to use if streaming, valid values are tar and xbstream (default "tar")
--xtrabackup_stripe_block_sizeuintSize in bytes of each block that gets sent to a given stripe before rotating to the next stripe (default 102400)
--xtrabackup_stripesuintIf greater than 0, use data striping across this many destination files to parallelize data transfer and decompression
--xtrabackup_userstringUser that xtrabackup will use to connect to the database server. This user must have all necessary privileges. For details, please refer to xtrabackup documentation.

Key Options #

  • --restore_from_backup: The default value for this flag is false. If set to true, and the my.cnf file was successfully loaded, then vttablet can perform automatic restores as follows:

    • If started against a mysql instance that has no data files, it will search the list of backups for the latest one, and initiate a restore. After this, it will point the mysql to the current primary and wait for replication to catch up. Once replication is caught up to the specified tolerance limit, it will advertise itself as serving. This will cause the vtgates to add it to the list of healthy tablets to serve queries from.
    • If this flag is true, but my.cnf was not loaded, then vttablet will fatally exit with an error message.
    • You can additionally control the level of concurrency for a restore with the --restore_concurrency flag. This is typically useful in cloud environments to prevent the restore process from becoming a 'noisy' neighbor by consuming all available disk IOPS.