wsrep_provider_options

wsrep_provider_options

The following options can be set as part of the Galera wsrep_provider_options variable. Dynamic options can be changed while the server is running.

Note that before Galera 3, the repl tag was named replicator.

base_host

• Description:
• Dynamic:
• Default: 127.0.0.1

base_port

• Description:
• Dynamic:
• Default: 4567

cert.log_conflicts

• Description:
• Dynamic:
• Default: no

evs.causal_keepalive_period

• Description: Used by the developers only, and not manually serviceable.
• Dynamic: No
• Default: The evs.keepalive_period.

evs.debug_log_mask

• Description: Controls EVS debug logging. Only effective when wsrep_debug is on.
• Dynamic: Yes
• Default: 0x1

evs.inactive_check_period

• Description: Frequency of checks for peer inactivity.
• Dynamic: No
• Default: PT1S

evs.inactive_timeout

• Description: Time limit that a node can be inactive before being pronounced as dead.
• Dynamic: No
• Default: PT15S

evs.info_log_mask

• Description: Controls extra EVS info logging. Bits:
  • 0x1 – extra view change information
  • 0x2 – extra state change information
  • 0x4 – statistics
  • 0x8 – profiling (only available in builds with profiling enabled)
• Dynamic: No
• Default: 0

evs.install_timeout

• Description: Timeout on waits for install message acknowledgments. Replaces evs.consensus_timeout.
• Dynamic: Yes
• Default: PT15S

evs.join_retrans_period

• Description: Time period for how often retransmission of EVS join messages when forming cluster membership should occur.
• Dynamic: Yes
• Default: PT1S

evs.keepalive_period

• Description: How often keepalive beacons should be transmitted when there's no other traffic.
• Dynamic: No
• Default: PT1S

evs.max_install_timeouts

• Description: Number of membership install rounds to attempt before timing out. The total rounds will be this value plus two.
• Dynamic: No
• Default: 1

evs.send_window

• Description: Maximum number of packets that can be replicated at a time, Cannot be less than evs.user_send_window, which applies to data packets only. In WAN environments can be set much higher than the default, for example 512.
• Dynamic: Yes
• Default: 4

evs.stats_report_period

• Description: Reporting period for EVS statistics.
• Dynamic: No
• Default: PT1M

evs.suspect_timeout

• Description: A node will be suspected to be dead after this period of inactivity. If all nodes agree, the node is dropped from the cluster before evs.inactive_timeout is reached.
• Dynamic: No
• Default: PT5S

evs.use_aggregate

• Description: If set to true (the default), small packets will be aggregated into one where possible.
• Dynamic: No
• Default: true

evs.user_send_window

• Description: Maximum number of data packets that can be replicated at a time. In WAN environments can be set much higher than the default, for example 512.
• Dynamic: Yes
• Default: 2

evs.version

• Description: Deprecated option. EVS version.
• Dynamic: No
• Default: 0

evs.view_forget_timeout

• Description: Drop past views from view history after that timeout.
• Dynamic: No
• Default: PT5M

gcache.dir

• Description: Directory where GCache files are placed.
• Dynamic: No
• Default: The working directory

gcache.keep_pages_size

• Description: Total size of the page storage pages for caching. One page is always present if only page storage is enabled.
• Dynamic: No
• Default: 0

gcache.mem_size

• Description: Maximum size of size of the malloc() store for setups that have spare RAM.
• Dynamic: No
• Default: 0

gcache.name

• Description: Gcache ring buffer storage file name. By default placed in the working directory, changing to another location or partition can reduce disk IO.
• Dynamic: No
• Default: galera.cache ---

gcache.page_size

• Description: Size of the page storage page files. These are prefixed by gcache.page. Can be set to as large as the disk can handle.
• Dynamic: No
• Default: 128Mb

gcache.size

• Description: Gcache ring buffer storage size, preallocated on startup.
• Dynamic: No
• Default: 128Mb

gcs.fc_debug

• Description: If set to a value greater than zero (the default), debug statistics about SST flow control will be posted each time after the specified number of writesets.
• Dynamic: No
• Default: 0

gcs.fc_factor

• Description:Fraction below gcs.fc_limit which if the recv queue drops below, replication resumes.
• Dynamic: Yes
• Default: 0.5

gcs.fc_limit

• Description: If the recv queue exceeds this many writesets, replication is paused. Can increase greatly in master-slave setups. Replication will resume again according to the gcs.fc_factor setting.
• Dynamic: Yes
• Default: 16

gcs.fc_master_slave

• Description: Whether to assume that the cluster only contains one master.
• Dynamic: No
• Default: NO

gcs.max_packet_size

• Description: Maximum packet size, after which writesets become fragmented.
• Dynamic: No
• Default: 32616

gcs.max_throttle

• Description: How much we can throttle replication rate during state transfer (to avoid running out of memory). Set it to 0.0 if stopping replication is acceptable for the sake of completing state transfer.
• Dynamic: No
• Default: 0.25

gcs.recv_q_hard_limit

• Description: Maximum size of the recv queue. If exceeded, the server aborts. Half of available RAM plus swap is a recommended size.
• Dynamic: No
• Default: LLONG_MAX

gcs.recv_q_soft_limit

• Description: Fraction of gcs.recv_q_hard_limit after which replication rate is throttled. The rate of throttling increases linearly from zero (the regular, varying rate of replication) at and below csrecv_q_soft_limit to one (full throttling) at gcs.recv_q_hard_limit
• Dynamic: No
• Default: 0.25

gcs.sync_donor

• Description: Whether or not the rest of the cluster should stay in sync with the donor. If set to YES (NO is default), if the donor is blocked by state transfer, the whole cluster is also blocked.
• Dynamic: No
• Default: NO

gmcast.listen_addr

• Description: Address Galera listens for connections from other nodes. Can be used to override the default port to listen, which is obtained from the connection address.
• Dynamic: No
• Default: tcp:0.0.0.0:4567

gmcast.mcast_addr

• Description: Not set by default, but if set, UDP multicast will be used for replication. Must be identical on all nodes.For example, gmcast.mcast_addr=239.192.0.11
• Dynamic: No
• Default: None

gmcast.mcast_ttl

• Description: Multicast packet TTL (time to live) value.
• Dynamic: No
• Default: 1

gmcast.peer_timeout

• Description: Connection timeout for initiating message relaying.
• Dynamic: No
• Default: PT3S

gmcast.segment

• Description: It defines the segment to which the node belongs.
• Dynamic: No
• Default: 0

gmcast.time_wait

• Description: Waiting time before allowing a peer that was declared outside of the stable view to reconnect.
• Dynamic: No
• Default: PT5S

gmcast.version

• Description: Deprecated option. Gmcast version.
• Dynamic: No
• Default: 0

ist.recv_addr

• Description: Address for listening for Incremental State Transfer.
• Dynamic: No
• Default: <address>:<port+1> from wsrep_node_address
• Introduced: Galera 2.0

pc.checksum

• Description: For debug purposes, by default true, indicates whether to checksum replicated messages on PC level. Safe to turn off.
• Dynamic: No
• Default: true

pc.ignore_quorum

• Description: Whether to ignore quorum calculations, for example when a master splits from several slaves, it will remain in operation if set to true (false is default). Use with care however, as in master-slave setups, slaves will not automatically reconnect to the master if set.
• Dynamic: Yes
• Default: false

pc.ignore_sb

• Description: Whether to permit updates to be processed even in the case of split brain (when a node is disconnected from its remaining peers). Safe in master-slave setups, but could lead to data inconsistency in a multi-master setup.
• Dynamic: Yes
• Default: false

pc.linger

• Description: Time that the PC protocol waits for EVS termination.
• Dynamic: No
• Default: PT2S

pc.version

• Description: Deprecated option. PC protocol version.
• Dynamic: No
• Default: 0

pc.weight

• Description: Node weight, used for quorum calculation. See the Codership article Weighted Quorum.
• Dynamic: Yes
• Default: 1

pc.npvo

• Description: If set to true (false is default), when there are primary component conficts, the most recent component will override the older.
• Dynamic: No
• Default: false

protonet.backend

• Description: Transport backend to use. Only ASIO is supported currently.
• Dynamic: No
• Default: asio

protonet.version

• Description: Deprecated option. Protonet version.
• Dynamic: No
• Default: 0

repl.causal_read_timeout

• Description: Timeout period for causal reads.
• Dynamic: Yes
• Default: PT30S

repl.commit_order

• Description: Whether or not out-of-order committing is permitted, and under what conditions. By default it is not permitted, but setting this can improve parallel performance.
  • 0 BYPASS: No commit order monitoring is done (useful for measuring the performance penalty).
  • 1 OOOC: Out-of-order committing is permitted for all transactions.
  • 2 LOCAL_OOOC: Out-of-order committing is permitted for local transactions only.
  • 3 NO_OOOC: Out-of-order committing is not permitted at all.
• Dynamic: No
• Default: 3

repl.max_ws_size

• Description:
• Dynamic:
• Default: 2147483647

repl.proto_max

• Description:
• Dynamic:
• Default: 5

socket.checksum

• Description: Method used for generating checksum. Note: If Galera 25.2.x and 25.3.x are both being used in the cluster, MariaDB with Galera 25.3.x must be started with wsrep_provider_options='socket.checksum=1' in order to make it backward compatible with Galera v2. Galera wsrep providers other than 25.3.x or 25.2.x are not supported.
• Dynamic: No
• Default: 2

See also

• Galera parameters documentation from Codership