MediaWiki  1.32.0
ILoadBalancer.php
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1 <?php
23 namespace Wikimedia\Rdbms;
24 
25 use Exception;
26 use InvalidArgumentException;
27 
78 interface ILoadBalancer {
80  const DB_REPLICA = -1;
82  const DB_MASTER = -2;
83 
85  const DOMAIN_ANY = '';
86 
88  const CONN_TRX_AUTOCOMMIT = 1;
89 
91  const STAGE_POSTCOMMIT_CALLBACKS = 'stage-postcommit-callbacks';
93  const STAGE_POSTROLLBACK_CALLBACKS = 'stage-postrollback-callbacks';
94 
121  public function __construct( array $params );
122 
130  public function getLocalDomainID();
131 
137  public function resolveDomainID( $domain );
138 
151  public function getReaderIndex( $group = false, $domain = false );
152 
165  public function waitFor( $pos );
166 
176  public function waitForOne( $pos, $timeout = null );
177 
185  public function waitForAll( $pos, $timeout = null );
186 
197  public function getAnyOpenConnection( $i, $flags = 0 );
198 
221  public function getConnection( $i, $groups = [], $domain = false, $flags = 0 );
222 
232  public function reuseConnection( IDatabase $conn );
233 
252  public function getConnectionRef( $i, $groups = [], $domain = false, $flags = 0 );
253 
272  public function getLazyConnectionRef( $i, $groups = [], $domain = false, $flags = 0 );
273 
292  public function getMaintenanceConnectionRef( $db, $groups = [], $domain = false, $flags = 0 );
293 
317  public function openConnection( $i, $domain = false, $flags = 0 );
318 
322  public function getWriterIndex();
323 
330  public function haveIndex( $i );
331 
338  public function isNonZeroLoad( $i );
339 
345  public function getServerCount();
346 
353  public function getServerName( $i );
354 
361  public function getServerInfo( $i );
362 
370  public function getServerType( $i );
371 
377  public function getServerAttributes( $i );
378 
383  public function getMasterPos();
384 
389  public function disable();
390 
394  public function closeAll();
395 
404  public function closeConnection( IDatabase $conn );
405 
411  public function commitAll( $fname = __METHOD__ );
412 
420  public function finalizeMasterChanges();
421 
431  public function approveMasterChanges( array $options );
432 
445  public function beginMasterChanges( $fname = __METHOD__ );
446 
452  public function commitMasterChanges( $fname = __METHOD__ );
453 
459  public function runMasterTransactionIdleCallbacks();
460 
466  public function runMasterTransactionListenerCallbacks();
467 
473  public function rollbackMasterChanges( $fname = __METHOD__ );
474 
480  public function flushReplicaSnapshots( $fname = __METHOD__ );
481 
489  public function flushMasterSnapshots( $fname = __METHOD__ );
490 
494  public function hasMasterConnection();
495 
500  public function hasMasterChanges();
501 
506  public function lastMasterChangeTimestamp();
507 
515  public function hasOrMadeRecentMasterChanges( $age = null );
516 
522  public function pendingMasterChangeCallers();
523 
529  public function getLaggedReplicaMode( $domain = false );
530 
539  public function laggedReplicaUsed();
540 
547  public function getReadOnlyReason( $domain = false, IDatabase $conn = null );
548 
554  public function allowLagged( $mode = null );
555 
559  public function pingAll();
560 
566  public function forEachOpenConnection( $callback, array $params = [] );
567 
573  public function forEachOpenMasterConnection( $callback, array $params = [] );
574 
580  public function forEachOpenReplicaConnection( $callback, array $params = [] );
581 
592  public function getMaxLag( $domain = false );
593 
604  public function getLagTimes( $domain = false );
605 
620  public function safeGetLag( IDatabase $conn );
621 
632  public function safeWaitForMasterPos( IDatabase $conn, $pos = false, $timeout = 10 );
633 
641  public function setTransactionListener( $name, callable $callback = null );
642 
648  public function setDomainPrefix( $prefix );
649 
662  public function setTableAliases( array $aliases );
663 
677  public function setIndexAliases( array $aliases );
678 }
Wikimedia\Rdbms\ILoadBalancer\haveIndex
haveIndex( $i)
Returns true if the specified index is a valid server index.
Wikimedia\Rdbms\ILoadBalancer\pendingMasterChangeCallers
pendingMasterChangeCallers()
Get the list of callers that have pending master changes.
Wikimedia\Rdbms\ILoadBalancer\setDomainPrefix
setDomainPrefix( $prefix)
Set a new table prefix for the existing local domain ID for testing.
Wikimedia\Rdbms\ILoadBalancer\resolveDomainID
resolveDomainID( $domain)
Wikimedia\Rdbms\ILoadBalancer\pingAll
pingAll()
Wikimedia\Rdbms\ILoadBalancer\waitForAll
waitForAll( $pos, $timeout=null)
Set the master wait position and wait for ALL replica DBs to catch up to it.
Wikimedia\Rdbms\ILoadBalancer\forEachOpenMasterConnection
forEachOpenMasterConnection( $callback, array $params=[])
Call a function with each open connection object to a master.
Wikimedia\Rdbms\ILoadBalancer\setIndexAliases
setIndexAliases(array $aliases)
Convert certain index names to alternative names before querying the DB.
Wikimedia\Rdbms\ILoadBalancer\getServerInfo
getServerInfo( $i)
Return the server info structure for a given index, or false if the index is invalid.
Wikimedia\Rdbms\ILoadBalancer\disable
disable()
Disable this load balancer.
Wikimedia\Rdbms\ILoadBalancer\getLazyConnectionRef
getLazyConnectionRef( $i, $groups=[], $domain=false, $flags=0)
Get a database connection handle reference without connecting yet.
Wikimedia\Rdbms\ILoadBalancer\getConnection
getConnection( $i, $groups=[], $domain=false, $flags=0)
Get a connection handle by server index.
Wikimedia\Rdbms
Definition: ChronologyProtector.php:24
Wikimedia\Rdbms\ILoadBalancer\isNonZeroLoad
isNonZeroLoad( $i)
Returns true if the specified index is valid and has non-zero load.
Wikimedia\Rdbms\ILoadBalancer\safeWaitForMasterPos
safeWaitForMasterPos(IDatabase $conn, $pos=false, $timeout=10)
Wait for a replica DB to reach a specified master position.
$params
$params
Definition: styleTest.css.php:44
Wikimedia\Rdbms\ILoadBalancer\getServerCount
getServerCount()
Get the number of defined servers (not the number of open connections)
Wikimedia\Rdbms\ILoadBalancer\getMaintenanceConnectionRef
getMaintenanceConnectionRef( $db, $groups=[], $domain=false, $flags=0)
Get a maintenance database connection handle reference for migrations and schema changes.
Wikimedia\Rdbms\ILoadBalancer\getConnectionRef
getConnectionRef( $i, $groups=[], $domain=false, $flags=0)
Get a database connection handle reference.
Wikimedia\Rdbms\ILoadBalancer\rollbackMasterChanges
rollbackMasterChanges( $fname=__METHOD__)
Issue ROLLBACK only on master, only if queries were done on connection.
php
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Definition: injection.txt:35
Wikimedia\Rdbms\IDatabase
Basic database interface for live and lazy-loaded relation database handles.
Definition: IDatabase.php:38
Wikimedia\Rdbms\ILoadBalancer\setTableAliases
setTableAliases(array $aliases)
Make certain table names use their own database, schema, and table prefix when passed into SQL querie...
Wikimedia\Rdbms\ILoadBalancer\getServerAttributes
getServerAttributes( $i)
Wikimedia\Rdbms\ILoadBalancer\allowLagged
allowLagged( $mode=null)
Disables/enables lag checks.
Wikimedia\Rdbms\ILoadBalancer\flushMasterSnapshots
flushMasterSnapshots( $fname=__METHOD__)
Commit all master DB transactions so as to flush any REPEATABLE-READ or SSI snapshots.
Wikimedia\Rdbms\ILoadBalancer\finalizeMasterChanges
finalizeMasterChanges()
Run pre-commit callbacks and defer execution of post-commit callbacks.
Wikimedia\Rdbms\ILoadBalancer\reuseConnection
reuseConnection(IDatabase $conn)
Mark a foreign connection as being available for reuse under a different DB domain.
Wikimedia\Rdbms\ILoadBalancer\getServerName
getServerName( $i)
Get the host name or IP address of the server with the specified index.
Wikimedia\Rdbms\ILoadBalancer\runMasterTransactionIdleCallbacks
runMasterTransactionIdleCallbacks()
Consume and run all pending post-COMMIT/ROLLBACK callbacks and commit dangling transactions.
Wikimedia\Rdbms\ILoadBalancer\forEachOpenConnection
forEachOpenConnection( $callback, array $params=[])
Call a function with each open connection object.
Wikimedia\Rdbms\ILoadBalancer\getMaxLag
getMaxLag( $domain=false)
Get the hostname and lag time of the most-lagged replica DB.
Wikimedia\Rdbms\ILoadBalancer\safeGetLag
safeGetLag(IDatabase $conn)
Get the lag in seconds for a given connection, or zero if this load balancer does not have replicatio...
Wikimedia\Rdbms\ILoadBalancer\getLocalDomainID
getLocalDomainID()
Get the local (and default) database domain ID of connection handles.
Wikimedia\Rdbms\ILoadBalancer\getMasterPos
getMasterPos()
Get the current master position for chronology control purposes.
Wikimedia\Rdbms\ILoadBalancer\hasMasterConnection
hasMasterConnection()
Wikimedia\Rdbms\ILoadBalancer\setTransactionListener
setTransactionListener( $name, callable $callback=null)
Set a callback via IDatabase::setTransactionListener() on all current and future master connections o...
Wikimedia\Rdbms\ILoadBalancer\getWriterIndex
getWriterIndex()
use
as see the revision history and available at free of to any person obtaining a copy of this software and associated documentation to deal in the Software without including without limitation the rights to use
Definition: MIT-LICENSE.txt:10
Wikimedia\Rdbms\ILoadBalancer\waitFor
waitFor( $pos)
Set the master wait position.
DB_REPLICA
const DB_REPLICA
Definition: defines.php:25
DB_MASTER
const DB_MASTER
Definition: defines.php:26
array
The wiki should then use memcached to cache various data To use multiple just add more items to the array To increase the weight of a make its entry a array("192.168.0.1:11211", 2))
Wikimedia\Rdbms\ILoadBalancer\getLaggedReplicaMode
getLaggedReplicaMode( $domain=false)
Wikimedia\Rdbms\ILoadBalancer\flushReplicaSnapshots
flushReplicaSnapshots( $fname=__METHOD__)
Commit all replica DB transactions so as to flush any REPEATABLE-READ or SSI snapshots.
Wikimedia\Rdbms\ILoadBalancer\openConnection
openConnection( $i, $domain=false, $flags=0)
Open a connection to the server given by the specified index.
Wikimedia\Rdbms\ILoadBalancer\commitAll
commitAll( $fname=__METHOD__)
Commit transactions on all open connections.
$fname
if(defined( 'MW_SETUP_CALLBACK')) $fname
Customization point after all loading (constants, functions, classes, DefaultSettings,...
Definition: Setup.php:121
$name
Allows to change the fields on the form that will be generated $name
Definition: hooks.txt:302
Wikimedia\Rdbms\ILoadBalancer\hasOrMadeRecentMasterChanges
hasOrMadeRecentMasterChanges( $age=null)
Check if this load balancer object had any recent or still pending writes issued against it by this P...
Wikimedia\Rdbms\ILoadBalancer\runMasterTransactionListenerCallbacks
runMasterTransactionListenerCallbacks()
Run all recurring post-COMMIT/ROLLBACK listener callbacks.
Wikimedia\Rdbms\ILoadBalancer\forEachOpenReplicaConnection
forEachOpenReplicaConnection( $callback, array $params=[])
Call a function with each open replica DB connection object.
Wikimedia\Rdbms\ILoadBalancer\laggedReplicaUsed
laggedReplicaUsed()
Checks whether the database for generic connections this request was both:
Wikimedia\Rdbms\ILoadBalancer\getReaderIndex
getReaderIndex( $group=false, $domain=false)
Get the index of the reader connection, which may be a replica DB.
Wikimedia\Rdbms\ILoadBalancer\approveMasterChanges
approveMasterChanges(array $options)
Perform all pre-commit checks for things like replication safety.
$options
null means default in associative array with keys and values unescaped Should be merged with default with a value of false meaning to suppress the attribute in associative array with keys and values unescaped & $options
Definition: hooks.txt:2036
Wikimedia\Rdbms\ILoadBalancer\__construct
__construct(array $params)
Construct a manager of IDatabase connection objects.
Wikimedia\Rdbms\ILoadBalancer\getAnyOpenConnection
getAnyOpenConnection( $i, $flags=0)
Get any open connection to a given server index, local or foreign.
Wikimedia\Rdbms\ILoadBalancer\commitMasterChanges
commitMasterChanges( $fname=__METHOD__)
Issue COMMIT on all open master connections to flush changes and view snapshots.
Wikimedia\Rdbms\ILoadBalancer\hasMasterChanges
hasMasterChanges()
Whether there are pending changes or callbacks in a transaction by this thread.
Wikimedia\Rdbms\ILoadBalancer\waitForOne
waitForOne( $pos, $timeout=null)
Set the master wait position and wait for a "generic" replica DB to catch up to it.
Wikimedia\Rdbms\ILoadBalancer\closeConnection
closeConnection(IDatabase $conn)
Close a connection.
Wikimedia\Rdbms\ILoadBalancer\getReadOnlyReason
getReadOnlyReason( $domain=false, IDatabase $conn=null)
Wikimedia\Rdbms\ILoadBalancer\getServerType
getServerType( $i)
Get DB type of the server with the specified index.
Wikimedia\Rdbms\ILoadBalancer\lastMasterChangeTimestamp
lastMasterChangeTimestamp()
Get the timestamp of the latest write query done by this thread.
Wikimedia\Rdbms\ILoadBalancer\beginMasterChanges
beginMasterChanges( $fname=__METHOD__)
Flush any master transaction snapshots and set DBO_TRX (if DBO_DEFAULT is set)
Wikimedia\Rdbms\ILoadBalancer\closeAll
closeAll()
Close all open connections.
Wikimedia\Rdbms\ILoadBalancer
Database cluster connection, tracking, load balancing, and transaction manager interface.
Definition: ILoadBalancer.php:78
Wikimedia\Rdbms\ILoadBalancer\getLagTimes
getLagTimes( $domain=false)
Get an estimate of replication lag (in seconds) for each server.