gcache.dir
This page is part of MariaDB's Documentation.
The parent of this page is: wsrep Provider Options for MariaDB Enterprise Server
Topics on this page:
Overview
Defines the directory where the writeset cache places its files
The wsrep_provider_options
system variable applies to MariaDB Enterprise Cluster, powered by Galera and to Galera Cluster available with MariaDB Community Server. This page relates specifically to the gcache.dir wsrep_provider_options
.
See also: wsrep Provider Options for MariaDB Enterprise Server 10.6, in 10.5 ES, in 10.4 ES, in 10.3 ES, in 10.2 ES, in 10.6 CS, in 10.5 CS, in 10.4 CS, in 10.3 CS, and in 10.2 CS
DETAILS
When nodes receive state transfers they cannot process incoming write-sets until they finish updating their state. Under certain methods, the node that sends the state transfer is similarly blocked. To prevent the database from falling further behind, GCache saves the incoming write-sets on memory mapped files to disk.
The gcache.dir
option specifies where the node should save these files for write-set caching. By default, GCache uses the working directory for the database server.
Attribute | Value |
---|---|
Option Name | gcache.dir |
Default Value | <path/to/data_directory> |
Dynamic | NO |
Debug |
|
EXAMPLES
Display Current Value
wsrep_provider_options
define optional settings the node passes to the wsrep provider.
To display current wsrep_provider_options
values:
SHOW GLOBAL VARIABLES LIKE 'wsrep_provider_options';
The expected output will display the option and the value. Options with no default value, for example SSL options, will not be displayed in the output.
Set in Configuration File
When changing a setting for a wsrep_
Options are set in the my.cnf
configuration file. Use the ;
delimiter to set multiple options.
The configuration file must be updated on each node. A restart to each node is needed for changes to take effect.
Use a quoted string that includes every option where you want to override the default value. Options that are not in the list will reset to their default value.
To set the option in the configuration file:
wsrep_provider_options='gcache.dir=/;gcache.debug=YES;gcs.fc_limit=NO;socket.send_buf_size=NO;evs.keepalive_period=PT3S'
Set Dynamically
The gcache.dir option cannot be set dynamically. It can only be set in the configuration file.
Trying to change a non-dynamic option with SET
results in an error:
ERROR 1210 (HY000): Incorrect arguments to SET
CHANGE HISTORY
Release Series | History |
---|---|
10.6 Enterprise |
|
10.6 Community |
|
10.5 Enterprise |
|
10.5 Community |
|
10.4 Enterprise |
|
10.4 Community |
|
10.3 Enterprise |
|
10.3 Community |
|
10.2 Enterprise |
|
10.2 Community |
|