手册:$wgDBservers

负载均衡设置: $wgDBservers
Settings for the database load balancer (database servers and load ratios).
引进版本：	1.2.0
移除版本：	仍在使用
允许的值：	参见下方
默认值：	false
其他设置： 按首字母排序 | 按功能排序

详情

Since MediaWiki 1.18 (Release notes) the database user for all databases configured in this array (if you use replication) needs the REPLICATION CLIENT privilege to determine the lag between master <-> replica.

Database load balancer. This is a two-dimensional array, an array of server info structures. Fields are:

host

Host name (see $wgDBserver ). For MySQL, it can contain a port or socket path after a colon.

dbname

Default database name (see $wgDBname )

user

DB user (see $wgDBuser )

password

DB password (see $wgDBpassword )

type

"mysql" or "pgsql" (see $wgDBtype )

load

ratio of DB_REPLICA load, must be >=0, the sum of all loads must be >0

groupLoads

array of load ratios, the key is the query group name. A query may belong to several groups, the most specific group defined here is used. (引入 自 1.4.3)

flags

bit field:

• DBO_DEFAULT -- turns on DBO_TRX only if $wgCommandLineMode  != true (recommended)
• DBO_DEBUG -- equivalent of $wgDebugDumpSql
• DBO_TRX -- automatically start transactions (see Database transactions )
• DBO_IGNORE -- ignore errors (not useful in LocalSettings.php)
• DBO_NOBUFFER -- turn off buffering (not useful in LocalSettings.php)
• DBO_SSL -- use a secure connection
• DBO_COMPRESS -- compress communication
• DBO_PERSISTENT -- enable persistent connections

Leave at false to use the single-server variables listed above.

The master must be the first entry in the array.

Example:

$wgDBservers = [
    [
        'host' => "master.serv.er",
        'dbname' => "wikidb",
        'user' => "wikiuser",
        'password' => "secret",
        'type' => "mysql",
        'flags' => DBO_DEFAULT,
        'load' => 0,
    ],
    [
        'host' => "replica1.serv.er",
        'dbname' => "wikidb",
        'user' => "wikiuser",
        'password' => "secret",
        'type' => "mysql",
        'flags' => DBO_DEFAULT,
        'load' => 1,
    ],
    [
        'host' => "replica2.serv.er",
        'dbname' => "wikidb",
        'user' => "wikiuser",
        'password' => "secret",
        'type' => "mysql",
        'flags' => DBO_DEFAULT,
        'load' => 1,
    ],
];

This would configure one master and two replicas, each replica getting an equal amount of read access load.

max lag

(optional) Maximum replication lag before a replica will be taken out of rotation

max threads

(（在1.23版本中已移除） optional) Maximum number of running threads

These and any other user-defined properties will be assigned to the mLBInfo member variable of the Database object.

MySQL specific options

lagDetectionMethod 

Set to one of (Seconds_Behind_Master,pt-heartbeat). pt-heartbeat assumes the table is at heartbeat.heartbeat and uses UTC timestamps in the heartbeat.ts column. (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)

lagDetectionOptions 

If using pt-heartbeat, this can be set to an array map to change the default behavior. Normally, the heartbeat row with the server ID of this server's master will be used. Set the "conds" field to override the query conditions, e.g. ['shard' => 's1'].

useGTIDs 

Use GTID methods like MASTER_GTID_WAIT() when possible.

sslKeyPath 

Path to key file.

sslCertPath 

Path to certificate file.

sslCAFile

Path to a single certificate authority PEM file. 1.30+

sslCAPath 

Path to certificate authority PEM directory.

sslCiphers 

Array list of allowable ciphers.

MSSQL specific options

port 

Port to connect to the server.

UseWindowsAuth 

Use Integrated Windows Authentication for authentication to the database instead of username/password.

PostgreSQL specific options

port 

Port to connect to the server.

keywordTableMap 

Map of reserved table names to alternative table names to use

SQLite specific options

dbFilePath 

Path to the database file.

dbDirectory 

Path to the directory containing the database file. Only needed if dbFilePath is not specified, and requires dbname.

dbname 

Name of the database (without the .sqlite extension). Only needed if dbFilePath is not specified, and requires dbDirectory.

trxMode 

Transaction mode. One of DEFERRED, IMMEDIATE or EXCLUSIVE.

Early versions

Versions of MediaWiki prior to 1.4.0 used a single-dimensional array, listing the server names, e.g. array("larousse", "pliny"), which was used in conjunction with $wgDBloads . From 1.4.0 onwards, $wgDBloads is deprecated and the above method must be used.

The groupLoads field was added in 1.4.3.

max lag and max threads (and the use of other user-defined properties) was added in 1.6.0

Warnings

If you switch to this, ensure you either keep $wgDBname set, or ensure $wgCookiePrefix and $wgCachePrefix are set explicitly.

See also

• $wgDBloads - （在1.4版本中已移除）
• $wgDBserver - for single-server setup