MediaWiki  1.30.0
ILoadBalancer.php
Go to the documentation of this file.
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_AUTO = 1;
89 
113  public function __construct( array $params );
114 
127  public function getReaderIndex( $group = false, $domain = false );
128 
141  public function waitFor( $pos );
142 
152  public function waitForOne( $pos, $timeout = null );
153 
161  public function waitForAll( $pos, $timeout = null );
162 
169  public function getAnyOpenConnection( $i );
170 
184  public function getConnection( $i, $groups = [], $domain = false, $flags = 0 );
185 
195  public function reuseConnection( $conn );
196 
212  public function getConnectionRef( $i, $groups = [], $domain = false, $flags = 0 );
213 
229  public function getLazyConnectionRef( $i, $groups = [], $domain = false, $flags = 0 );
230 
246  public function getMaintenanceConnectionRef( $db, $groups = [], $domain = false, $flags = 0 );
247 
264  public function openConnection( $i, $domain = false, $flags = 0 );
265 
269  public function getWriterIndex();
270 
277  public function haveIndex( $i );
278 
285  public function isNonZeroLoad( $i );
286 
292  public function getServerCount();
293 
300  public function getServerName( $i );
301 
309  public function getServerType( $i );
310 
318  public function getServerInfo( $i );
319 
328  public function setServerInfo( $i, array $serverInfo );
329 
334  public function getMasterPos();
335 
340  public function disable();
341 
345  public function closeAll();
346 
355  public function closeConnection( IDatabase $conn );
356 
362  public function commitAll( $fname = __METHOD__ );
363 
370  public function finalizeMasterChanges();
371 
381  public function approveMasterChanges( array $options );
382 
395  public function beginMasterChanges( $fname = __METHOD__ );
396 
402  public function commitMasterChanges( $fname = __METHOD__ );
403 
412  public function runMasterPostTrxCallbacks( $type );
413 
419  public function rollbackMasterChanges( $fname = __METHOD__ );
420 
428  public function suppressTransactionEndCallbacks();
429 
435  public function flushReplicaSnapshots( $fname = __METHOD__ );
436 
440  public function hasMasterConnection();
441 
446  public function hasMasterChanges();
447 
452  public function lastMasterChangeTimestamp();
453 
461  public function hasOrMadeRecentMasterChanges( $age = null );
462 
468  public function pendingMasterChangeCallers();
469 
475  public function getLaggedReplicaMode( $domain = false );
476 
485  public function laggedReplicaUsed();
486 
493  public function getReadOnlyReason( $domain = false, IDatabase $conn = null );
494 
500  public function allowLagged( $mode = null );
501 
505  public function pingAll();
506 
512  public function forEachOpenConnection( $callback, array $params = [] );
513 
519  public function forEachOpenMasterConnection( $callback, array $params = [] );
520 
526  public function forEachOpenReplicaConnection( $callback, array $params = [] );
527 
538  public function getMaxLag( $domain = false );
539 
550  public function getLagTimes( $domain = false );
551 
566  public function safeGetLag( IDatabase $conn );
567 
578  public function safeWaitForMasterPos( IDatabase $conn, $pos = false, $timeout = 10 );
579 
587  public function setTransactionListener( $name, callable $callback = null );
588 
594  public function setDomainPrefix( $prefix );
595 
608  public function setTableAliases( array $aliases );
609 }
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\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\runMasterPostTrxCallbacks
runMasterPostTrxCallbacks( $type)
Issue all pending post-COMMIT/ROLLBACK callbacks.
Wikimedia\Rdbms\ILoadBalancer\forEachOpenMasterConnection
forEachOpenMasterConnection( $callback, array $params=[])
Call a function with each open connection object to a master.
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 by index.
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\reuseConnection
reuseConnection( $conn)
Mark a foreign connection as being available for reuse under a different DB domain.
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.
$fname
if(!defined( 'MEDIAWIKI')) $fname
This file is not a valid entry point, perform no further processing unless MEDIAWIKI is defined.
Definition: Setup.php:36
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:40
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.
$name
Allows to change the fields on the form that will be generated $name
Definition: hooks.txt:302
Wikimedia\Rdbms\ILoadBalancer\getConnectionRef
getConnectionRef( $i, $groups=[], $domain=false, $flags=0)
Get a database connection handle reference.
Wikimedia\Rdbms\ILoadBalancer\getAnyOpenConnection
getAnyOpenConnection( $i)
Get any open connection to a given server index, local or foreign.
Wikimedia\Rdbms\ILoadBalancer\rollbackMasterChanges
rollbackMasterChanges( $fname=__METHOD__)
Issue ROLLBACK only on master, only if queries were done on connection.
php
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35
Wikimedia\Rdbms\IDatabase
Basic database interface for live and lazy-loaded relation database handles.
Definition: IDatabase.php:40
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\allowLagged
allowLagged( $mode=null)
Disables/enables lag checks.
Wikimedia\Rdbms\ILoadBalancer\finalizeMasterChanges
finalizeMasterChanges()
Perform all pre-commit callbacks that remain part of the atomic transactions and disable any post-com...
Wikimedia\Rdbms\ILoadBalancer\getServerName
getServerName( $i)
Get the host name or IP address of the server with the specified index.
Wikimedia\Rdbms\ILoadBalancer\suppressTransactionEndCallbacks
suppressTransactionEndCallbacks()
Suppress all pending post-COMMIT/ROLLBACK callbacks.
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\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()
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
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 snapshot.
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.
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\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\setServerInfo
setServerInfo( $i, array $serverInfo)
Sets the server info structure for the given index.
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:1965
Wikimedia\Rdbms\ILoadBalancer\__construct
__construct(array $params)
Construct a manager of IDatabase connection objects.
Wikimedia\Rdbms\ILoadBalancer\commitMasterChanges
commitMasterChanges( $fname=__METHOD__)
Issue COMMIT on all master connections where writes where done.
Wikimedia\Rdbms\ILoadBalancer\hasMasterChanges
hasMasterChanges()
Determine if there are pending changes 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.
$flags
it s the revision text itself In either if gzip is the revision text is gzipped $flags
Definition: hooks.txt:2801
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.
array
the array() calling protocol came about after MediaWiki 1.4rc1.
$type
$type
Definition: testCompression.php:48