Replication and Binary Log System Variables

Complete Replication and Binary Log System Variables reference for MariaDB. Complete guide for configuration values, scope settings, and performance impact.

The terms master and slave have historically been used in replication, and MariaDB has begun the process of adding primary and replica synonyms. The old terms continue to be used to maintain backward compatibility - see MDEV-18777 to follow progress on this effort.

Overview

This page lists system variables that are related to binary logging and replication.

See Server System Variables for a complete list of system variables and instructions on setting them, as well as System variables for global transaction ID.

Also see mariadbd replication options for related options that are not system variables (such as binlog_do_db and binlog_ignore_db).

Global Defaults

This functionality is available from MariaDB 12.3.

The following variables serve as the global default for the corresponding MASTER_* option in the CHANGE MASTER TO statement. The value is inherited from this system variable when the user enters the DEFAULT keyword for that option.

• replication_connect_retry

• replication_retry_count

• replication_heartbeat_period

• replication_ssl

• replication_ssl_ca

• replication_ssl_capath

• replication_ssl_cert

• replication_ssl_key

• replication_ssl_cipher

• replication_ssl_crl

• replication_ssl_crlpath

• replication_ssl_verify_server_cert

• replication_use_gtid

For more details, see CHANGE MASTER TO.

Variable Descriptions

auto_increment_increment

• Description: The increment for all AUTO_INCREMENT values on the server, by default 1. Intended for use in primary-to-primary replication.

• Command line: --auto-increment-increment[=#]

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1

• Range: 1 to 65535

auto_increment_offset

• Description: The offset for all AUTO_INCREMENT values on the server, by default 1. Intended for use in primary-to-primary replication. Should be not be larger than auto_increment_increment. See AUTO_INCREMENT#Replication.

• Command line: --auto-increment-offset[=#]

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1

• Range: 1 to 65535

binlog_alter_two_phase

• Description: When set, split ALTER at binary logging into two statements: START ALTER and COMMIT/ROLLBACK ALTER. The ON setting is recommended for long-running ALTER TABLE statements, so it could start on replica before its actual execution on primary.

• Command line: --binlog-alter-two-phase[={0|1}]

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

• Introduced: MariaDB 10.8.1

binlog_annotate_row_events

• Description: This option tells the primary to write annotate_rows_events to the binary log.

• Command line: --binlog-annotate-row-events[={0|1}]

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

binlog_cache_size

• Description: If the binary log is active, this variable determines the size in bytes, per-connection, of the cache holding a record of binary log changes during a transaction. A separate variable, binlog_stmt_cache_size, sets the upper limit for the statement cache. The binlog_cache_disk_use and binlog_cache_use server status variables indicates whether this variable needs to be increased (you want a low ratio of binlog_cache_disk_use to binlog_cache_use).

• Command line: --binlog-cache-size=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 32768

• Range - 32 bit: 4096 to 4294967295

• Range - 64 bit: 4096 to 18446744073709547520

binlog_checksum

• Description: Specifies the type of BINLOG_CHECKSUM_ALG for log events in the binary log.

• Command line:

  • --binlog-checksum=name

  • --binlog-checksum=[0|1]

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Default Value: CRC32

• Valid Values: NONE (0), CRC32 (1)

binlog_commit_wait_count

• Description: Configures the behavior of group commit for the binary log, which can help increase transaction throughput and is used to enable conservative mode of in-order parallel replication. With group commit for the binary log, the server can delay flushing a committed transaction into binary log until the given number of transactions are ready to be flushed as a group. However, the delay is not longer than the value set by binlog_commit_wait_usec. The default value of 0 means that no delay is introduced. Setting this value can reduce I/O on the binary log and give an increased opportunity for parallel apply on the replica when conservative mode of in-order parallel replication is enabled, but too high a value decreases the transaction throughput. By monitoring the status variable binlog_group_commit_trigger_count, it is possible to see how often this is occurring.

• If the server detects that one of the committing transactions T1 holds an InnoDB row lock that another transaction T2 is waiting for, the commit completes immediately without further delay. This helps avoid losing throughput when many transactions need conflicting locks. This often makes it safe to use this option without losing throughput on a replica with conservative mode of in-order parallel replication, provided the value of slave_parallel_threads is sufficiently high.

• Command line: --binlog-commit-wait-count=#]

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

binlog_commit_wait_usec

• Description: Configures the behavior of group commit for the binary log, which can help increase transaction throughput and is used to enable conservative mode of in-order parallel replication. With group commit for the binary log, the server can delay flushing a committed transaction into binary log until the transaction has waited the configured number of microseconds. By monitoring the status variable binlog_group_commit_trigger_timeout, it is possible to see how often group commits are made due to binlog_commit_wait_usec. As soon as the number of pending commits reaches binlog_commit_wait_count, the wait is terminated, though. Thus, this setting only takes effect if binlog_commit_wait_count is non-zero.

• Command line: --binlog-commit-wait-usec#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 100000

• Range: 0 to 18446744073709551615

binlog_direct_non_transactional_updates

• Description: Replication inconsistencies can occur due when a transaction updates both transactional and non-transactional tables and the updates to the non-transactional tables are visible before being written to the binary log. This is because, to preserve causality, the non-transactional statements are written to the transaction cache, which is only flushed on commit. Setting binlog_direct_non_transactional_updates to 1 (0 is default) causes non-transactional tables to be written straight to the binary log, rather than the transaction cache. This setting has no effect when row-based binary logging is used, as it requires statement-based logging. See binlog_format. Use with care, and only in situations where no dependencies exist between the non-transactional and transactional tables, for example, inserting into a non-transactional table based upon the results of a SELECT from a transactional table.

• Command line: --binlog-direct-non-transactional-updates[=value]

• Scope: Global, Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF (0)

binlog_do_db

• Description: This option allows you to configure a replication primary to write statements and transactions affecting databases that match a specified name into its binary log. Since the filtered statements or transactions are not be present in the binary log, its replicas are not be able to replicate them.

  • This option does not work with cross-database updates with statement-based logging. See the Statement-Based Logging section for more information.

  • Until MariaDB 11.2.0, only available as an option, not a system variable. This option can not be set dynamically.

  • When setting it on the command-line or in a server option group in an option file, the option does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the option multiple times.

  • See Replication Filters for more information.

• Command line: --binlog-do-db=#

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: NULL

• Introduced: MariaDB 11.2.0 (as a system variable)

binlog_expire_logs_seconds

• Description: If non-zero, binary logs are purged after binlog_expire_logs_seconds seconds. Possible purges happen at startup and at binary log rotation. From MariaDB 10.6.1, binlog_expire_logs_seconds and expire_logs_days are forms of aliases, such that changes to one automatically reflect in the other.

• Command line: --binlog-expire-logs-seconds=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 8553600

• Introduced: MariaDB 10.6.1

binlog_file_cache_size

• Description: Size of in-memory cache that is allocated when reading binary log and relay log files.

• Command line: --binlog-file-cache-size=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 16384

• Range: 8192 to 18446744073709551615

binlog_format

• Description: Determines whether replication is row-based, statement-based or mixed. Statement-based was the default until MariaDB 10.2.3. Be careful of changing the binary log format when a replication environment is already running. See Binary Log Formats. A replica applies any events it gets from the primary, regardless of the binary log format. binlog_format only applies to normal (not replicated) updates.

• Command line: --binlog-format=format

• Scope: Global, Session

• Dynamic: Yes

• Data Type: enumeration

• Default Value: MIXED

• Valid Values: ROW, STATEMENT or MIXED

binlog_gtid_index

• Description: Enable the creation of a GTID index for every binlog file, and the use of such index for speeding up GTID lookup in the binlog. See Binlog indexing.

• Command line: --binlog-gtid-index{=0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

• Introduced: MariaDB 11.4

binlog_gtid_index_page_size

• Description: Page size to use for the binlog GTID index. See Binlog indexing.

• Command line: --binlog-gtid-index-page-size=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 4096

• Range: 64 to 16777216

• Introduced: MariaDB 11.4

binlog_gtid_index_span_min

• Description: Control sparseness of the binlog GTID index. If set, at most one index record is added for every N bytes of binlog file written, to reduce the size of the index. Normally, this does not need tuning. See Binlog indexing.

• Command line: --binlog-gtid-index-span-min=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 65536

• Range: 1 to 1073741824

• Introduced: MariaDB 11.4

binlog_ignore_db

• Description: This option allows you to configure a replication primary to not write statements and transactions affecting databases that match a specified name into its binary log. Since the filtered statements or transactions are not be present in the binary log, its replicas are not able to replicate them.

  • This option does not work with cross-database updates with statement-based logging. See the Statement-Based Logging section for more information.

  • When setting it on the command-line or in a server option group in an option file, the option does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the option multiple times.

  • See Replication Filters for more information.

• Command line: --binlog-ignore-db=name

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: NULL

• Introduced: MariaDB 11.2.0

binlog_large_commit_threshold

• Description: Increases transaction concurrency for large transactions (for instance, those with sizes larger than this value) by using the large transaction's cache file as a new binary log and rotating the active binary log to the large transaction's cache file at commit time. This avoids the default commit logic that copies the transaction cache data to the end of the active binary log file while holding a lock that prevents other transactions from binlogging.

• Command line: --binlog-large-commit-threshold=val

• Scope: Global

• Dynamic: Yes

• Data Type: bigint unsigned

• Default Value: 134217728

• Range: 10485760 to 18446744073709551615

• Introduced: MariaDB 11.7

binlog_legacy_event_pos

• Description: Fill in the end_log_pos field of all events in the binlog, even when doing so costs performance. Can be used in case some old application needs it for backwards compatibility. Setting this option can hurt binlog scalability.

• Command line: --binlog-legacy-event-pos{=0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

• Introduced: MariaDB 11.4

binlog_optimize_thread_scheduling

• Description: Run fast part of group commit in a single thread, to optimize kernel thread scheduling. On by default. Disable to run each transaction in group commit in its own thread, which can be slower at very high concurrency. This option is mostly for testing one algorithm versus another, and it should not normally be necessary to change it. Deprecated in MariaDB 11.7, as the option was initially added to provide a safe alternative for the newly added binlog group commit logic, such that when 0, it would disable a leader thread from performing the binlog write for all transactions that are a part of the group commit. Problems related to the binlog group commit optimization are expected to be addressed by now, so the option has been deprecated and is going to be removed in future.

• Command line: --binlog-optimize-thread-scheduling or --skip-binlog-optimize-thread-scheduling

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

• Deprecated: MariaDB 11.7

binlog_row_event_fragment_threshold

• Description: When a Rows_log_event exceeds this threshold, it is fragmented into multiple Partial_rows_log_event events in the binary log, each of it configured to maximum size. That is, all Partial_rows_log_event events up to the last in the group have this configured maximum size, and the last event takes the remaining size. This is relevant for events that would surpass the slave_max_allowed_packet length when sending to the replica, and thereby a sensible value would reflect the slave's configured slave_max_allowed_packet size.

• Command line: --binlog-row-event-fragment-threshold

• Scope: Global

• Dynamic: Yes

• Data Type: INT unsigned

• Default Value: 1GB

• Introduced: MariaDB 12.3

binlog_row_event_max_size

• Description: The maximum size of a row-based binary log event in bytes. Rows are grouped into events smaller than this size if possible. The value has to be a multiple of 256.

• Command line: --binlog-row-event-max-size=val

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 8192

• Range: 256 to 4294967040 (in multiples of 256)

• Introduced: MariaDB 11.2.0

binlog_row_image

• Description: Controls the logging format in row-based replication. In row-based replication (the variable has no effect with statement-based replication), each row change event contains an image for matching against when choosing the row to be updated, and another image containing the changes. Before the introduction of this variable, all columns were logged for both of these images. In certain circumstances, this is not necessary, and memory, disk and network resources can be saved by partial logging. Note that to safely change this setting from the default, the table being replicated to must contain identical primary key definitions, and columns must be present, in the same order, and use the same data types as the original table. If these conditions are not met, matches may not be correctly determined and updates and deletes may diverge on the replica, with no warnings or errors returned.

  • FULL: All columns in the before and after image are logged. This is the default, and the only behavior in earlier versions.

  • NOBLOB: mariadbd avoids logging blob and text columns whenever possible (eg, blob column was not changed or is not part of primary key).

  • MINIMAL: A PK equivalent (PK columns or full row if there is no PK in the table) is logged in the before image, and only changed columns are logged in the after image.

  • FULL_NODUP: All columns are logged in the before image but only changed columns or all columns of inserted record are logged in the after image. This is essentially the same as FULL, but takes less space. From MariaDB 11.4.

• Command line: --binlog-row-image=value

• Scope: Global, Session

• Dynamic: Yes

• Data Type: enum

• Default Value: FULL

• Valid Values:

  • <= MariaDB 11.3: FULL, NOBLOB or MINIMAL

  • >=MariaDB 11.4: FULL, NOBLOB, MINIMAL or FULL_NODUP

binlog_row_metadata

• Description: Controls the format used for binlog metadata logging – value is one of the following:

  • NO_LOG: No metadata is logged (default).

  • MINIMAL: Only metadata required by a replica is logged.

  • FULL: All metadata is logged.

• Command line: --binlog-row-metadata=*value*

• Scope: Global

• Dynamic: Yes

• Data Type: enum

• Default Value: NO_LOG

• Valid Values: NO_LOG, MINIMAL, FULL

• Introduced: MariaDB 10.5.0

binlog_space_limit

• Description: Alias for max_binlog_total_size.

• Introduced: MariaDB 11.4

binlog_stmt_cache_size

• Description: If the binary log is active, this variable determines the size in bytes of the cache holding a record of binary log changes outside of a transaction. The variable binlog_cache_size, determines the cache size for binary log statements inside a transaction. The binlog_stmt_cache_disk_use and binlog_stmt_cache_use server status variables indicates whether this variable needs to be increased (you want a low ratio of binlog_stmt_cache_disk_use to binlog_stmt_cache_use).

• Command line: --binlog-stmt-cache-size=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 32768

• Range - 32 bit: 4096 to 4294967295

• Range - 64 bit: 4096 to 18446744073709547520

create_tmp_table_binlog_formats

• Description: The binary logging formats under which the primary logs CREATE TEMPORARY statements to the binary log. If CREATE TEMPORARY is not logged, all usage of the temporary table is logged in ROW format. Allowed values are STATEMENT or MIXED,STATEMENT.

• Command line: --create-tmp-table-binlog-formats=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: enum

• Default Value: STATEMENT

• Valid Values: STATEMENT or MIXED,STATEMENT

• Introduced: MariaDB 12.0

default_master_connection

• Description: In multi-source replication, specifies which connection is used for commands and variables if you don't specify a connection.

• Command line: None

• Scope: Session

• Dynamic: Yes

• Data Type: string

• Default Value: '' (empty string)

encrypt_binlog

• Description: Encrypt binary logs (including relay logs). See Data at Rest Encryption and Encrypting Binary Logs.

• Command line: --encrypt-binlog[={0|1}]

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

expire_logs_days

• Description: Number of days after which the binary log can be automatically removed. By default, 0, or no automatic removal. When using replication, should always be set higher than the maximum lag by any replica. Removals take place when the server starts up, when the binary log is flushed, when the next binary log is created after the previous one reaches the maximum size, or when running PURGE BINARY LOGS. Units are 1/1000000 precision (double). expire_logs_days and binlog_expire_logs_seconds are forms of aliases, such that changes to one automatically reflect in the other. Some container configs explicitly set expire_logs_days to 10, rather than leave it as the default, zero.

• Command line: --expire-logs-days=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0.000000

• Range: 0 to 99

init_slave

• Description: Similar to init_connect, but the string contains one or more SQL statements (separated by semicolons) that are executed by a replica server each time the SQL thread starts. These statements are only executed after the acknowledgement is sent to the replica and START SLAVE completes.

• Command line: --init-slave=name

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Related variables: init_connect

log_bin

• Description: Whether binary logging is enabled or not. If the --log-bin option is used, log_bin is set to ON, otherwise to OFF. If no name option is given for --log-bin, datadir/log-basename-bin or datadir/mysql-bin are used (the latter is used if --log-basename is not specified). We strongly recommend you use either --log-basename, or to specify a filename to ensure that replication doesn't stop if the real hostname of the computer changes. The name option can optionally include an absolute path. If no path is specified, the log is written to the data directory. The name can optionally include the file extension; if it does, it is stripped, and only the file basename is used.

• Command line: --log-bin[=name]

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

• Related variables: sql_log_bin

log_bin_basename

• Description: The full path of the binary log file names, excluding the extension. Its value is derived from the rules specified in log_bin system variable. This is a read-only variable only, there is no corresponding configuration file setting or command line option by the same name, use log_bin to set the basename path instead.

• Command line: No commandline option

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: None

• Dynamic: No

log_bin_compress

• Description: Whether or not the binary log can be compressed. 0 (the default) means no compression. See Compressing Events to Reduce Size of the Binary Log.

• Command line: --log-bin-compress

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

log_bin_compress_min_len

• Description: Minimum length of sql statement (in statement mode) or record (in row mode) that can be compressed. See Compressing Events to Reduce Size of the Binary Log.

• Command line: --log-bin-compress-min-len

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 256

• Range: 10 to 1024

log_bin_index

• Description: File that holds the names for last binlog files. If --log-basename is also set, log_bin_index should be placed after in the config files. Later settings override earlier settings, so log-basename override any earlier log file name settings.

• Command line: --log-bin-index=name

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: None

log_bin_trust_function_creators

• Description: Functions and triggers can be dangerous when used with replication. Certain types of functions and triggers may have unintended consequences when the statements are applied on a replica. For that reason, there are some restrictions on the creation of functions and triggers when the binary log is enabled by default, such as:

  • When log_bin_trust_function_creators is OFF and log_bin is ON, CREATE FUNCTION and ALTER FUNCTION statements trigger an error if the function is defined with any of the NOT DETERMINISTIC, CONTAINS SQL or MODIFIES SQL DATA characteristics.

  • This means that when log_bin_trust_function_creators is OFF and log_bin is ON, CREATE FUNCTION and ALTER FUNCTION statements only succeed if the function is defined with any of the DETERMINISTIC, NO SQL, or READS SQL DATA characteristics.

  • When log_bin_trust_function_creators is OFF and log_bin is ON, the SUPER privilege is also required to execute the following statements:

    • CREATE FUNCTION

    • CREATE TRIGGER

    • DROP TRIGGER

  • Setting log_bin_trust_function_creators to ON removes these requirements around functions characteristics and the SUPER privileges.

  • See Binary Logging of Stored Routines for more information.

• Command line: --log-bin-trust-function-creators[={0|1}]

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

log_slow_slave_statements

• Description: Log slow statements executed by replica thread to the slow log if it is open.

• Command line: --log-slow-slave-statements

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

log_slave_updates

• Description: If set to 0, the default, updates on a replica received from a primary during replication are not logged in the replica's binary log. If set to 1, they are. The replica's binary log needs to be enabled for this to have an effect. Set to 1 if you want to daisy-chain the replicas.

• Command line: --log-slave-updates

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

master_info_file

• Description: The location and name of the file that remembers the master and where the I/O replication thread is in the master's binlogs. Defaults to master.info.

• Command line: --master-info-file=val

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: master.info

• Introduced: MariaDB 12.0 (as a system variable, previously it was just an option)

master_verify_checksum

• Description: Verify binlog checksums when reading events from the binlog on the primary.

• Command line: --master-verify-checksum=[0|1]

• Scope: Global

• Access Type: Can be changed dynamically

• Data Type: bool

• Default Value: OFF (0)

max_binlog_cache_size

• Description: Restricts the size in bytes used to cache a multi-transactional query. If more bytes are required, a Multi-statement transaction required more than 'max_binlog_cache_size' bytes of storage error is generated. If the value is changed, current sessions are unaffected, only sessions started subsequently. See max_binlog_stmt_cache_size and binlog_cache_size.

• Command line: --max-binlog-cache-size=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 18446744073709547520

• Range: 4096 to 18446744073709547520

max_binlog_size

• Description: If the binary log exceeds this size in bytes after a write, the server rotates it by closing it and opening a new binary log. Single transactions are always stored in the same binary log, so the server waits for open transactions to complete before rotating. This figure also applies to the size of relay logs if max_relay_log_size is set to zero.

• Command line: --max-binlog-size=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1073741824 (1GB)

• Range: 4096 to 1073741824 (4KB to 1GB)

max_binlog_stmt_cache_size

• Description: Restricts the size used to cache non-transactional statements. See max_binlog_cache_size and binlog_stmt_cache_size.

• Command line: --max-binlog-stmt-cache-size=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 18446744073709547520 (64 bit), 4294963200 (32 bit)

• Range: 4096 to 18446744073709547520

max_binlog_total_size

• Description: Maximum space in bytes to use for all binary logs. Extra logs are deleted on server start, log rotation, FLUSH LOGS statements, or when writing to binlog. Default is 0, which means no size restrictions. See also slave_connections_needed_for_purge.

• Command line: --max-binlog-size=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 18446744073709551615

• Introduced: MariaDB 11.4

max_relay_log_size

• Description: The replica rotates its relay log if it exceeds this size after a write. If set to 0, the max_binlog_size setting is used instead. Previously global only, since the implementation of multi-source replication, it can be set per session as well.

• Command line: --max-relay-log-size=#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0, or 4096 to 1073741824 (4KB to 1GB)

read_binlog_speed_limit

• Description: Used to restrict the speed at which a replica can read the binlog from the primary. This can be used to reduce the load on a primary if many replicas need to download large amounts of old binlog files at the same time. The network traffic is restricted to the specified number of kilobytes per second.

• Command line: --read-binlog-speed-limit=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0 (no limit)

• Range: 0 to 18446744073709551615

relay_log

• Description: Relay log basename. If not set, the basename of the files is hostname-relay-bin, or derived from --log-basename. If --log-basename is also set, relay_log should be placed after in the config files. Later settings override earlier settings, so log-basename overrides any earlier log file name settings.

• Command line: --relay-log=file_name

• Scope: Global

• Dynamic: No

• Data Type: filename

• Default Value: '' (none)

relay_log_basename

• Description: The full path of the relay log file names, excluding the extension. Its value is derived from the relay-log variable value.

• Command line: No commandline option

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: None

• Dynamic: No

relay_log_index

• Description: Name and location of the relay log index file, the file that keeps a list of the last relay logs. Defaults to hostname-relay-bin.index, or derived from --log-basename. If --log-basename is also set, relay_log_index should be placed after in the config files. Later settings override earlier settings, so log-basename overrides any earlier log file name settings.

• Command line: --relay-log-index=name

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: None

relay_log_info_file

• Description: Name and location of the file where the RELAY_LOG_FILE and RELAY_LOG_POS options (i.e. the relay log position) for the CHANGE MASTER statement are written. The replica's SQL thread keeps this relay log position updated as it applies events.

  • See CHANGE MASTER TO: Option Persistence for more information.

• Command line: --relay-log-info-file=file_name

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: relay-log.info

relay_log_purge

• Description: If set to 1 (the default), relay logs is purged as soon as they are no longer necessary.

• Command line: --relay-log-purge={0|1}

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: ON

• Note: In MySQL and in MariaDB before version 10.0.8 this variable was silently changed if you did CHANGE MASTER.

relay_log_recovery

• Description: If set to 1 (0 is default), on startup the replica drops all relay logs that haven't yet been processed, and retrieve relay logs from the primary. Can be useful after the replica has crashed to prevent the processing of corrupt relay logs. relay_log_recovery should always be set together with relay_log_purge. Setting relay-log-recovery=1 with relay-log-purge=0 can cause the relay log to be read from files that were not purged, leading to data inconsistencies.

• Command line: --relay-log-recovery

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

relay_log_space_limit

• Description: Specifies the maximum space to be used for the relay logs. The IO thread stops until the SQL thread has cleared the backlog. By default 0, or no limit.

• Command line: --relay-log-space-limit=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 0

• Range - 32 bit: 0 to 4294967295

• Range - 64 bit: 0 to 18446744073709547520

replicate_annotate_row_events

• Description: Tells the replica to reproduce annotate_rows_events received from the primary in its own binary log. This option is sensible only when used in tandem with the log_slave_updates option.

• Command line: --replicate-annotate-row-events

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: ON

replicate_do_db

• Description: This system variable allows you to configure a replica to apply statements and transactions affecting databases that match a specified name.

  • This system variable does not work with cross-database updates with statement-based logging. See the Statement-Based Logging section for more information.

  • When setting it dynamically with SET GLOBAL, the system variable accepts a comma-separated list of filters.

  • When setting it on the command-line or in a server option group in an option file, the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times.

  • See Replication Filters for more information.

• Command line: --replicate-do-db=name

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Default Value: '' (empty)

replicate_do_table

• Description: This system variable allows you to configure a replica to apply statements and transactions that affect tables that match a specified name. The table name is specified in the format: dbname.tablename.

  • This system variable does not work with cross-database updates with statement-based logging. See the Statement-Based Logging section for more information.

  • When setting it dynamically with SET GLOBAL, the system variable accepts a comma-separated list of filters.

  • When setting it on the command-line or in a server option group in an option file, the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times.

  • See Replication Filters for more information.

• Command line: --replicate-do-table=name

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Default Value: '' (empty)

replicate_events_marked_for_skip

• Description: Tells the replica whether to replicate events that are marked with the @@skip_replication flag. See Selectively skipping replication of binlog events for more information.

• Command line: --replicate-events-marked-for-skip

• Scope: Global

• Dynamic: Yes

• Data Type: enumeration

• Default Value: replicate

• Valid Values: REPLICATE, FILTER_ON_SLAVE, FILTER_ON_MASTER

replicate_ignore_db

• Description: This system variable allows you to configure a replica to ignore statements and transactions affecting databases that match a specified name.

  • This system variable does not work with cross-database updates with statement-based logging. See the Statement-Based Logging section for more information.

  • When setting it dynamically with SET GLOBAL, the system variable accepts a comma-separated list of filters.

  • When setting it on the command-line or in a server option group in an option file, the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times.

  • See Replication Filters for more information.

• Command line: --replicate-ignore-db=name

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Default Value: '' (empty)

replicate_ignore_table

• Description: This system variable allows you to configure a replica to ignore statements and transactions that affect tables that match a specified name. The table name is specified in the format: dbname.tablename.

  • This system variable does not work with cross-database updates with statement-based logging. See the Statement-Based Logging section for more information.

  • When setting it dynamically with SET GLOBAL, the system variable accepts a comma-separated list of filters.

  • When setting it on the command-line or in a server option group in an option file, the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times.

  • See Replication Filters for more information.

• Command line: --replicate-ignore-table=name

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Default Value: '' (empty)

replicate_rewrite_db

• Description: This option allows you to configure a replica to rewrite database names. It uses the format primary_database->replica_database. If a replica encounters a binary log event in which the default database (i.e. the one selected by the USE statement) is primary_database, then the replica applies the event in replica_database instead.

  • This option does not work with cross-database updates with statement-based logging. See the Statement-Based Logging section for more information.

  • This option only affects statements that involve tables. This option does not affect statements involving the database itself, such as CREATE DATABASE, ALTER DATABASE, and DROP DATABASE.

  • When setting it on the command-line or in a server option group in an option file, the option does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the option multiple times.

  • See Replication Filters for more information.

• Command line: --replicate-rewrite-db=primary_database->replica_database

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Default Value: '' (empty)

• Introduced: MariaDB 10.11.0

replicate_same_server_id

• Description: In replication, if set to 1, do not skip events having our server id. Default value is 0 (to break infinite loops in circular replication). Can't be set to 1 if --log-slave-updates is used.

• Command line: --replicate-same-server-id[={0|1}]

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

• Introduced: MariaDB 12.0 (as a system variable, previously just an option)

replicate_wild_do_table

• Description: This system variable allows you to configure a replica to apply statements and transactions that affect tables that match a specified wildcard pattern. The wildcard pattern uses the same semantics as the LIKE operator.

  • This system variable works with cross-database updates with statement-based logging. See the Statement-Based Logging section for more information.

  • When setting it dynamically with SET GLOBAL, the system variable accepts a comma-separated list of filters.

  • When setting it on the command-line or in a server option group in an option file, the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times.

  • See Replication Filters for more information.

• Command line: --replicate-wild-do-table=name

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Default Value: '' (empty)

replicate_wild_ignore_table

• Description: This system variable allows you to configure a replica to ignore statements and transactions that affect tables that match a specified wildcard pattern. The wildcard pattern uses the same semantics as the LIKE operator.

  • This system variable work with cross-database updates with statement-based logging. See the Statement-Based Logging section for more information.

  • When setting it dynamically with SET GLOBAL, the system variable accepts a comma-separated list of filters.

  • When setting it on the command-line or in a server option group in an option file, the system variable does not accept a comma-separated list. If you would like to specify multiple filters, then you need to specify the system variable multiple times.

  • See Replication Filters for more information.

• Command line: --replicate-wild-ignore-table=name

• Scope: Global

• Dynamic: Yes

• Data Type: string

• Default Value: '' (empty)

replication_connect_retry

• Description: When a replica tries to connect to the primary, it automatically waits for a second between connection retry attempts. This value is implemented when a CHANGE MASTER TO statement uses MASTER_CONNECT_RETRY = DEFAULT.

• Command line: --replication-connect-retry=#

• Scope: Global

• Data Type: numeric

• Default Value: 60

replication_retry_count

• Description: The default number of connection retries that a replica does before failing. This value is applied when a CHANGE MASTER TO statement uses MASTER_RETRY_COUNT = DEFAULT.

• Command line: --replication-retry-count=#

• Scope: Global

• Data Type: numeric

• Default Value: 0

replication_heartbeat_period

• Description: The default number of connection retries that a replica does before failing. This value is applied when a CHANGE MASTER TO statement uses MASTER_RETRY_COUNT = DEFAULT.

• Command line: --replication-heartbeat-period=#

• Scope: Global

• Data Type: numeric

• Default Value: 0

replication_ssl

• Description: By default, SLS/TLS is enabled or disabled for replication connections. This value is applied when MASTER_SSL = DEFAULT is used in a CHANGE MASTER TO statement.

• Command line: --replication-ssl={0|1}

• Scope: Global

• Data Type: boolean

• Default Value: 0

replication_ssl_ca

• Description: The default path to a PEM file that contains trusted CA certificates for SSL/TLS replication connections. This value can be used as the default in the CHANGE MASTER TO statement when the MASTER_SSL_CA = DEFAULT is specified.

• Command line: --replication-ssl-ca=filename

• Scope: Global

• Data Type: string

• Default Value: empty

replication_ssl_capath

• Description: Specifies the path that contains trusted CA certificates for SSL/TLS replication connections. This value can be used as the default in the CHANGE MASTER TO statement when MASTER_SSL_CAPATH = DEFAULT is specified.

• Command line: --replication-ssl-capath=path_name

• Scope: Global

• Data Type: string

• Default Value: empty

replication_ssl_cert

• Description: Sets the default path to the client SSL/TLS certificate file used for replication connections. When MASTER_SSL_CERT = DEFAULT is specified, in a CHANGE MASTER TO statement, this value is used.

• Command line: --replication-ssl-cert=filename

• Scope: Global

• Data Type: string

• Default Value: empty

replication_ssl_key

• Description: Sets the default path to the client SSL/TLS private key file for replication connections. If MASTER_SSL_KEY = DEFAULT is specified in the CHANGE MASTER TO statement, the system applies this value.

• Command line: --replication-ssl-key=filename

• Scope: Global

• Data Type: string

• Default Value: empty

replication_ssl_cipher

• Description: Specifies the default list of permitted SSL cipher suites for replication connections. When MASTER_SSL_CIPHER = DEFAULT is specified in a CHANGE MASTER TO statement, this value is used.

• Command line: --replication-ssl-cipher=filename

• Scope: Global

• Data Type: string

• Default Value: empty

replication_ssl_crl

• Description: Specifies the default path to a certificate revocation list (CRL) file for SSL/TLS replication connections. When MASTER_SSL_CRL = DEFAULT is specified in a CHANGE MASTER TO statement, this value is used.

• Command line: --replication-ssl-crl=file_name

• Scope: Global

• Data Type: string

• Default Value: empty

replication_ssl_crlpath

• Description: Specifies the default path containing CRL file for SSL/TLS replication connections. When MASTER_SSL_CRLPATH = DEFAULT is specified in a CHANGE MASTER TO statement, this value is used.

• Command line: --replication-ssl-crlpath=directoryname

• Scope: Global

• Data Type: string

• Default Value: empty

replication_ssl_verify_server_cert

• Description: When enabled, the replica verifies the server's SSL certificate on replication connections. When MASTER_SSL_VERIFY_SERVER_CERT = DEFAULT is mentioned in a CHANGE MASTER TO statement, this value is used.

• Command line: --replication-ssl-verify-server-cert={0|1}

• Scope: Global

• Data Type: boolean

• Default Value: 1 (verify)

replication_use_gtid

• Description: Determines the default GTID mode for replication connections. When MASTER_USE_GTID = DEFAULT is specified in a CHANGE MASTER TO statement, this value is applied.

• Command line: --replication-use-gtid=name

• Scope: Global

• Data Type: enumeration (current_pos, salve_pos, no)

• Default Value: no

report_host

• Description: The host name or IP address the replica reports to the primary when it registers. If left unset, the replica does not register itself. Reported by SHOW SLAVE HOSTS. Note that it is not sufficient for the primary to simply read the IP of the replica from the socket once the replica connects. Due to NAT and other routing issues, that IP may not be valid for connecting to the replica from the primary or other hosts.

• Command line: --report-host=host_name

• Scope: Global

• Dynamic: No

• Data Type: string

report_password

• Description: Replica password reported to the primary when it registers. Reported by SHOW SLAVE HOSTS if --show-slave-auth-info is set. This password has no connection with user privileges or with the replication user account password.

• Command line: --report-password=password

• Scope: Global

• Dynamic: No

• Data Type: string

report_port

• Description: The command line option sets the TCP/IP port for connecting to the replica that is reported to the replicating primary during the replica's registration. Viewing the variable shows this value.

• Command line: --report-port=#

• Scope: Global

• Dynamic: No

• Data Type: numeric

• Default Value: 0

• Range: 0 to 65535

report_user

• Description: Replica's account user name reported to the primary when it registers. Reported by SHOW SLAVE HOSTS if --show-slave-auth-info is set. This username has no connection with user privileges or with the replication user account.

• Command line: --report-user=name

• Scope: Global

• Dynamic: No

• Data Type: string

server_id

• Description: This system variable is used with MariaDB replication to identify unique primary and replica servers in a topology. This system variable is also used with the binary log to determine which server a specific transaction originated on.

  • When MariaDB replication is used with standalone MariaDB Server, each server in the replication topology must have a unique server_id value.

  • When MariaDB replication is used with MariaDB Galera Cluster, see Using MariaDB Replication with MariaDB Galera Cluster: Setting server_id on Cluster Nodes for more information on how to set the server_id values.

• Command line: --server-id =#

• Scope: Global, Session

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1

• Range: 1 to 4294967295

show_slave_auth_info

• Description: Show user and password in SHOW REPLICA HOSTS on this primary.

• Command line: --show-slave-auth-info[={0|1}]

• Scope: Global

• Dynamic: No

• Data Type: boolean

• Default Value: OFF

• Introduced: MariaDB 12.0 (as a system variable, previously it was just an option)

skip_parallel_replication

• Description: If set when a transaction is written to the binlog, parallel apply of that transaction is avoided on a replica where slave_parallel_mode is not aggressive. Can be used to avoid unnecessary rollback and retry for transactions that are likely to cause a conflict if replicated in parallel. See parallel replication.

• Command line: None

• Scope: Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

skip_replication

• Description: Changes are logged into the binary log with the @@skip_replication flag set. Such events are not be replicated by replica that run with --replicate-events-marked-for-skip set different from its default of REPLICATE. See Selectively skipping replication of binlog events for more information.

• Command line: None

• Scope: Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: OFF

slave_abort_blocking_timeout

• Description: Maximum time a replica DDL waits for a blocking SELECT or other user query until that query is aborted. The argument is treated as a decimal value with nanosecond precision. The variable is intended to solve a problem where a long-running SELECT on a replica causes DDL to wait for that SELECT to complete, potentially causing massive replica lag.

• Command line: --slave-abort-blocking-timeout=num

• Scope: Global

• Dynamic: Yes

• Data Type: double

• Default Value: 31536000.000000

• Range: 0 to 31536000

• Introduced: MariaDB 11.7

slave_compressed_protocol

• Description: If set to 1 (0 is the default), uses compression for the replica/primary protocol if both primary and replica support this.

• Command line: --slave-compressed-protocol

• Scope: Global

• Dynamic: Yes

• Data Type: boolean

• Default Value: 0

slave_connections_needed_for_purge

• Description: Minimum number of connected replicas required for automatic binary log purge with max_binlog_total_size, binlog_expire_logs_seconds or expire_logs_days. Change of the value triggers an attempt to purging, though without binlog rotation, with the purged set of files satisfying the above two parameters and the value that is set itself.

• Command line: --slave-connections-needed-for-purge=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1; 0 on Galera cluster nodes.

• Range: 0 to 18446744073709551615

• Introduced: MariaDB 11.4

slave_ddl_exec_mode

• Description: Modes for how replication of DDL events should be executed. Legal values are STRICT and IDEMPOTENT (default). In IDEMPOTENT mode, the replica does not stop for failed DDL operations that would not cause a difference between the primary and the replica. In particular CREATE TABLE is treated as CREATE OR REPLACE TABLE and DROP TABLE is treated as DROP TABLE IF EXISTS.

• Command line: --slave-ddl-exec-mode=name

• Scope: Global

• Dynamic: Yes

• Data Type: enumeration

• Default Value: IDEMPOTENT

• Valid Values: IDEMPOTENT, STRICT

slave_domain_parallel_threads

• Description: When set to a non-zero value, each replication domain in one primary connection can reserve at most that many worker threads at any one time, leaving the rest (up to the value of slave_parallel_threads) free for other primary connections or replication domains to use in parallel. See Parallel Replication for details.

• Command line: --slave-domain-parallel-threads=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Valid Values: 0 to 16383

slave_exec_mode

• Description: Determines the mode used for replication error checking and conflict resolution. STRICT mode is the default, and catches all errors and conflicts. IDEMPOTENT mode suppresses duplicate key or no key errors, which can be useful in certain replication scenarios, such as when there are multiple primaries, or circular replication.

• Scope: Global

• Dynamic: Yes

• Data Type: enumeration

• Default Value: IDEMPOTENT (NDB), STRICT (All)

• Valid Values: IDEMPOTENT, STRICT

slave_load_tmpdir

• Description: Directory where the replica stores temporary files for replicating LOAD DATA INFILE statements. If not set, the replica uses tmpdir. Should be set to a disk-based directory that survives restarts, or else replication can fail.

• Command line: --slave-load-tmpdir=path

• Scope: Global

• Dynamic: No

• Data Type: file name

• Default Value: /tmp

slave_max_allowed_packet

• Description: Maximum packet size in bytes for replica SQL and I/O threads. This value overrides max_allowed_packet for replication purposes. Set in multiples of 1024 (the minimum) up to 1GB

• Command line: --slave-max-allowed-packet=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 1073741824

• Range: 1024 to 1073741824

slave_max_statement_time

• Description: A query that has taken more than this in seconds to run on the replica is aborted. The argument is treated as a decimal value with microsecond precision. A value of 0 (default) means no timeout.

• Command line: --slave-max-statement-time=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0.000000

• Range: 0 to 31536000

• Introduced: MariaDB 10.10

slave_net_timeout

• Description: Time in seconds for the replica to wait for more data from the primary before considering the connection broken, after which it aborts the read and attempt to reconnect. The retry interval is determined by the MASTER_CONNECT_RETRY open for the CHANGE MASTER statement, while the maximum number of reconnection attempts is set by the master-retry-count option. The first reconnect attempt takes place immediately.

• Command line: --slave-net-timeout=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value:

  • 60 (1 minute)

• Range: 1 to 31536000

slave_parallel_max_queued

• Description: When parallel_replication is used, the SQL thread reads ahead in the relay logs, queueing events in memory while looking for opportunities for executing events in parallel. This system variable sets a limit for how much memory it uses for this.

  • The configured value of this system variable is actually allocated for each worker thread, so the total allocation is actually equivalent to the following:

    • slave_parallel_max_queued * slave_parallel_threads

  • This system variable is only meaningful when parallel replication is configured (i.e. when slave_parallel_threads > 0).

  • See Parallel Replication: Configuring the Maximum Size of the Parallel Slave Queue for more information.

• Command line: --slave-parallel-max-queued=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 131072

• Range: 0 to 2147483647

slave_parallel_mode

• Description: Controls what transactions are applied in parallel when using parallel replication.

  • optimistic: tries to apply most transactional DML in parallel and handles any conflicts with rollback and retry. See optimistic mode.

  • conservative: limits parallelism in an effort to avoid any conflicts. See conservative mode.

  • aggressive: tries to maximize the parallelism, possibly at the cost of increased conflict rate.

  • minimal: only parallelizes the commit steps of transactions.

  • none disables parallel apply completely.

• Command line: None

• Scope: Global

• Dynamic: Yes

• Data Type: enum

• Default Value: optimistic (>= MariaDB 10.5.1), conservative (<= MariaDB 10.5.0)

• Valid Values: conservative, optimistic, none, aggressive and minimal

slave_parallel_threads

• Description: This system variable is used to configure parallel replication.

  • If this system variable is set to a value greater than 0, then its value determines how many replica worker threads are created to apply binary log events in parallel.

  • If this system variable is set to 0 (which is the default value), no replica worker threads are created. Instead, when replication is enabled, binary log events are applied by the replica's SQL thread.

  • The replica threads must be stopped in order to change this option's value dynamically.

  • Events that were logged with GTIDs with different gtid_domain_id values can be applied in parallel in an out-of-order manner. Each gtid_domain_id can use the number of threads configured by slave_domain_parallel_threads.

  • Events that were group-committed on the primary can be applied in parallel in an in-order manner, and the specific behavior can be configured by setting slave_parallel_mode.

• Command line: --slave-parallel-threads=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 16383

slave_parallel_workers

• Description: Alias for slave_parallel_threads.

• Command line: --slave-parallel-workers=#

slave_run_triggers_for_rbr

• Description: See Running triggers on the slave for Row-based events for a description and use-case for this setting.

• Command line: --slave-run-triggers-for-rbr=value

• Scope: Global

• Dynamic: Yes

• Data Type: enum

• Default Value: NO

• Valid Values: NO, YES, LOGGING, or ENFORCE (>= MariaDB 10.5.2)

slave_skip_errors

• Description: When an error occurs on the replica, replication usually halts. This option permits a list of error codes to ignore, and for which replication continues. This option should never be needed in normal use, and careless use could lead to replica that are out of sync with primaries. Error codes are in the format of the number from the replica error log. Using all as an option permits the replica the keep replicating no matter what error it encounters, an option you would never normally need in production, and which could rapidly lead to data inconsistencies. A count of these is kept in slave_skipped_errors.

• Command line: --slave-skip-errors=[error_code1,error_code2,...|all|ddl_exist_errors]

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value: OFF

• Valid Values: [list of error codes], ALL, OFF

slave_sql_verify_checksum

• Description: Verify binlog checksums when the replica SQL thread reads events from the relay log.

• Command line: --slave-sql-verify-checksum=[0|1]

• Scope: Global

• Access Type: Can be changed dynamically

• Data Type: bool

• Default Value: ON (1)

slave_transaction_retries

• Description: Number of times a replication replica retries to execute an SQL thread after it fails due to InnDB deadlock or by exceeding the transaction execution time limit. If after this number of tries the SQL thread has still failed to execute, the replica stops with an error. See also the innodb_lock_wait_timeout system variable.

• Command line: --slave-transaction-retries=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 10

• Range - 32 bit: 0 to 4294967295

• Range - 64 bit: 0 to 18446744073709547520

slave_transaction_retry_errors

• Description: When an error occurs during a transaction on the replica, replication usually halts. By default, transactions that caused a deadlock or elapsed lock wait timeout is retried. One can add other errors to the list of errors that should be retried by adding a comma-separated list of error numbers to this variable. This is particularly useful in some Spider setups. Some recommended errors to retry for Spider are 1020, 1158, 1159, 1160, 1161, 1429, 2013, 12701 (these are in the default value in recent versions).

• Command line: --slave-transaction_retry-errors=[error_code1,error_code2,...]

• Scope: Global

• Dynamic: No

• Data Type: string

• Default Value:

  • 1158,1159,1160,1161,1205,1213,1020,1429,2013,12701 (>= MariaDB 10.6.18, MariaDB 10.11.8, MariaDB 11.0.6, MariaDB 11.1.5, MariaDB 11.2.4, MariaDB 11.4.2)

  • 1158,1159,1160,1161,1205,1213,1429,2013,12701 (>= MariaDB 10.4.5)

• Valid Values: comma-separated list of error codes

• Introduced: MariaDB 10.3.3

slave_transaction_retry_interval

• Description: Interval in seconds for the replica SQL thread to retry a failed transaction due to a deadlock, elapsed lock waits timeout or an error listed in slave_transaction_retry_errors. The interval is calculated as max(slave_transaction_retry_interval, min(retry_count, 5)).

• Command line: --slave-transaction-retry-interval=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 3600

slave_type_conversions

• Description: Determines the type conversion mode on the replica when using row-based replication, including replications in MariaDB Galera cluster. Multiple options can be set, delimited by commas. If left empty, the default, type conversions are disallowed. The variable is dynamic and a change in its value takes effect immediately. This variable tells the server what to do if the table definition is different between the primary and replica (for example a column has a data type of INT on the primary and BIGINT on the replica).

  • ALL_NON_LOSSY means that all safe conversions (no data loss) are allowed.

  • ALL_LOSSY means that all lossy conversions are allowed (for example 'bigint' to 'int'). This, however, does not imply that safe conversions (non-lossy) are allowed as well. In order to allow all conversions, one needs to allow both lossy as well as non-lossy conversions by setting this variable to ALL_NON_LOSSY,ALL_LOSSY.

  • Empty (default) means that the server should give an error and replication should stop if the table definition is different between the primary and replica.

• Command line: --slave-type-conversions=set

• Scope: Global

• Dynamic: Yes

• Data Type: set

• Default Value: Empty variable

• Valid Values: ALL_LOSSY, ALL_NON_LOSSY, empty

sql_log_bin

• Description: If set to 0 (1 is the default), no logging to the binary log is done for the client. Only clients with the SUPER privilege can update this variable. Does not affect the replication of events in a Galera cluster. Note that sql_log_bin has no effect if log_bin is not set.

• Scope: Session

• Dynamic: Yes

• Data Type: boolean

• Default Value: 1

• Related variables: log_bin

sql_slave_skip_counter

• Description: Number of events that a replica skips from the primary. If this would cause the replica to begin in the middle of an event group, the replica instead starts from the beginning of the next event group. See SET GLOBAL sql_slave_skip_counter.

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

sync_binlog

• Description: MariaDB synchronizes its binary log file to disk after this many events. The default is 0, in which case the operating system handles flushing the file to disk. 1 is the safest, but slowest, choice, since the file is flushed after each write. If autocommit is enabled, there is one write per statement, otherwise there's one writes per transaction. If the disk has cache backed by battery, synchronization is fast, and a more conservative number can be chosen.

• Command line: --sync-binlog=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 0

• Range: 0 to 4294967295

sync_master_info

• Description: A replication replica synchronizes its master.info file to disk after this many events. If set to 0, the operating system handles flushing the file to disk.

• Command line: --sync-master-info=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 10000

sync_relay_log

• Description: The MariaDB server synchronizes its relay log to disk after the specified number of writes to the log. 1 is the safest, but slowest, choice, since the file is flushed after each write. If autocommit is enabled, there is one write per statement, otherwise there's one write per transaction. If the disk has cache backed by battery, synchronization is fast and a more conservative number can be chosen.

• Command line: --sync-relay-log=#

• Scope: Global

• Dynamic: Yes

• Data Type: numeric

• Default Value: 10000

sync_relay_log_info

• Description: A replication replica synchronizes its relay-log.info file to disk after the specified number of transactions. 1 is the most secure choice, because at most one event can be lost in the event of a crash, but it's also the slowest.

• Command line: --sync-relay-log-info=#

• Scope: Global,

• Dynamic: Yes

• Data Type: numeric

• Default Value: 10000

• Range: 0 to 4294967295

See Also

• Full list of MariaDB options, system and status variables

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