Index¶

variable base_host¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	value of the wsrep_node_address

This variable sets the value of the node’s base IP. This is an IP address on which Galera listens for connections from other nodes. Setting this value incorrectly would stop the node from communicating with other nodes.

variable base_port¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	4567

This variable sets the port on which the Galera listens for connections from other nodes. Setting this value incorrectly would stop the node from communicating with other nodes.

variable cert.log_conflicts¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	no

This variable is used to specify if the details of the certification failures should be logged.

variable debug¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	Yes
Default Value:	no

When this variable is set to Yes it will enable debugging.

variable evs.causal_keepalive_period¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	value of evs.keepalive_period

This variable is used for development purposes and shouldn’t be used by regular users.

variable evs.debug_log_mask¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	Yes
Default Value:	0x1

This variable is used for EVS (Extended Virtual Synchrony) debugging it can be used only when wsrep_debug is set to ON.

variable evs.inactive_check_period¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	PT0.5S

This variable defines how often to check for peer inactivity.

variable evs.inactive_timeout¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	PT15S

This variable defines the inactivity limit, once this limit is reached the node will be pronounced dead.

variable evs.info_log_mask¶

Command Line:	No
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	0

This variable is used for controlling the extra EVS info logging.

variable evs.install_timeout¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	Yes
Default Value:	PT15S

This variable defines the timeout on waiting for install message acknowledgments.

variable evs.join_retrans_period¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	PT1S

This variable defines how often to retransmit EVS join messages when forming cluster membership.

variable evs.keepalive_period¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	PT1S

This variable defines how often will keepalive beacons will be emmited (in the absence of any other traffic).

variable evs.max_install_timeouts¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	1

This variable defines how many membership install rounds to try before giving up (total rounds will be evs.max_install_timeouts + 2).

variable evs.send_window¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	4

This variable defines the maximum number of data packets in replication at a time. For WAN setups may be set considerably higher, e.g. 512. This variable must be no less than evs.user_send_window.

variable evs.stats_report_period¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	PT1M

This variable defines the control period of EVS statistics reporting.

variable evs.suspect_timeout¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	PT5S

This variable defines the inactivity period after which the node is “suspected” to be dead. If all remaining nodes agree on that, the node will be dropped out of cluster even before evs.inactive_timeout is reached.

variable evs.use_aggregate¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	true

When this variable is enabled smaller packets will be aggregated into one.

variable evs.user_send_window¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	Yes
Default Value:	2

This variable defines the maximum number of data packets in replication at a time. For WAN setups may be set considerably higher, e.g. 512.

variable evs.version¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	0

This status variable is used to check which EVS (Extended Virtual Synchrony) protocol version is used.

variable evs.view_forget_timeout¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	P1D

This variable defines the timeout after which past views will be dropped from history.

variable gcache.dir¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	datadir

This variable can be used to define the location of the galera.cache file.

variable gcache.keep_pages_size¶

Command Line:	Yes
Config File:	Yes
Scope:	Local, Global
Dynamic:	No
Default Value:	0

This variable is used to specify total size of the page storage pages to keep for caching purposes. If only page storage is enabled, one page is always present.

variable gcache.mem_size¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	0

This variable is used to define how much RAM system has available. NOTE: This parameter is for use on systems with spare memory. You should not use it otherwise, as it may lead to unexpected results.

variable gcache.name¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	/var/lib/mysql/galera.cache

This variable can be used to specify the name of the Galera cache file.

variable gcache.page_size¶

Command Line:	No
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	128M

This variable can be used to specify the size of the page files in the page storage.

variable gcache.size¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	128M

Size of the transaction cache for Galera replication. This defines the size of the galera.cache file which is used as source for IST. If this value is bigger there are better chances that the re-joining node will get IST instead of SST.

variable gcs.fc_debug¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	0

This variable specifies after how many writesets the debug statistics about SST flow control will be posted.

variable gcs.fc_factor¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	1.0

This variable is used for replication flow control. Replication will be paused till the value of this variable goes below the value of gcs.fc_factor * gcs.fc_limit.

variable gcs.fc_limit¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	16

This variable is used for replication flow control. When slave queue exceeds this limit replication will be paused.

variable gcs.fc_master_slave¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	no

This variable is used to specify if there is only one master node in the cluster.

variable gcs.max_packet_size¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	64500

This variable is used to specify the writeset size after which they will be fragmented.

variable gcs.max_throttle¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	0.25

This variable specifies how much the replication can be throttled during the state transfer in order to avoid running out of memory. Value can be set to 0.0 if stopping replication is acceptable in order to finish state transfer.

variable gcs.recv_q_hard_limit¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	9223372036854775807

This variable specifies the maximum allowed size of the receive queue. This should normally be half of (RAM + swap). If this limit is exceeded, Galera will abort the server.

variable gcs.recv_q_soft_limit¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	0.25

This variable specifies the fraction of the gcs.recv_q_hard_limit after which replication rate will be throttled.

variable gcs.sync_donor¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	no

This variable controls if the rest of the cluster should be in sync with the donor node. When this variable is set to Yes whole cluster will be blocked if the donor node is blocked with SST.

variable gmcast.listen_addr¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	tcp://0.0.0.0:4567

This variable defines the address on which node listens to connections from other nodes in the cluster.

variable gmcast.mcast_addr¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	None

This variable should be set up if UDP multicast should be used for replication.

variable gmcast.mcast_ttl¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	1

This variable can be used to define TTL for multicast packets.

variable gmcast.peer_timeout¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	PT3S

This variable specifies the connection timeout to initiate message relaying.

variable gmcast.time_wait¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	PT5S

This variable specifies the time to wait until allowing peer declared outside of stable view to reconnect.

variable gmcast.version¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	0

This status variable is used to check which gmcast protocol version is being used.

variable ist.recv_addr¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	value of wsrep_node_address

This variable specifies the address on which nodes listens for Incremental State Transfer (IST).

variable pc.announce_timeout¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	PT3S

Cluster joining announcements are sent every 1/2 second for this period of time or less if the other nodes are discovered.

variable pc.checksum¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	false

This variable controls will the replicated messages will be checksummed or not.

variable pc.ignore_quorum¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	Yes
Default Value:	false

When this variable is set to TRUE node will completely ignore the quorum calculations. This should be used with extreme caution even in master-slave setups, because slaves won’t automatically reconnect to master in this case.

variable pc.ignore_sb¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	Yes
Default Value:	false

When this variable us set ti TRUE node will process updates even in the case of split brain. This should be used with extreme caution in multi-master setup, but should simplify things in master-slave cluster (especially if only 2 nodes are used).

variable pc.linger¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	PT20S

This variable specifies the period which PC protocol waits for EVS termination.

variable pc.npvo¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	false

When this variable is set to TRUE more recent primary component overrides older ones in case of conflicting prims.

variable pc.version¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	0

This status variable is used to check which PC protocol version is being used.

variable pc.wait_prim¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	true

When this variable is set to true node will wait for pc.wait_prim_timeout value for the primary component. This option can be used to bring up a non-primary component and make it primary with pc.bootstrap option.

variable pc.wait_prim_timeout¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	P30S

This variable is used to define how much time node should wait for the primary component.

variable pc.weight¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	Yes
Default Value:	1

This variable specifies the node weight that’s going to be used for Weighted Quorum calculations.

variable protonet.backend¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	asio

This variable is used to define which transport backend should be used. Currently only ASIO is supported.

variable protonet.version¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	0

This status variable is used to show which transport backend protocol version is used.

variable repl.causal_read_timeout¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	Yes
Default Value:	PT30S

This variable specifies the causal read timeout.

variable repl.commit_order¶

Command Line:	Yes
Config File:	Yes
Scope:	Global
Dynamic:	No
Default Value:	3

This variable is used to specify Out-Of-Order committing (which is used to improve parallel applying performance). Allowed values are:

• 0 - BYPASS: all commit order monitoring is turned off (useful for measuring performance penalty)
• 1 - OOOC: allow out of order committing for all transactions
• 2 - LOCAL_OOOC: allow out of order committing only for local transactions
• 3 - NO_OOOC: no out of order committing is allowed (strict total order committing)