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Wikimedia\Rdbms\ILBFactory Interface Reference

An interface for generating database load balancers. More...

Inheritance diagram for Wikimedia\Rdbms\ILBFactory:

Public Member Functions

 __construct (array $conf)
 Construct a manager of ILoadBalancer instances. More...
 
 appendShutdownCPIndexAsQuery ( $url, $index)
 Append ?cpPosIndex parameter to a URL for ChronologyProtector purposes if needed. More...
 
 beginMasterChanges ( $fname=__METHOD__)
 
 beginPrimaryChanges ( $fname=__METHOD__)
 Flush any primary transaction snapshots and set DBO_TRX (if DBO_DEFAULT is set) More...
 
 closeAll ()
 Close all connections on instantiated tracked load balancer instances. More...
 
 commitAll ( $fname=__METHOD__, array $options=[])
 Commit open transactions on all connections. More...
 
 commitAndWaitForReplication ( $fname, $ticket, array $opts=[])
 Call commitPrimaryChanges() and waitForReplication() if $ticket indicates it is safe. More...
 
 commitMasterChanges ( $fname=__METHOD__, array $options=[])
 
 commitPrimaryChanges ( $fname=__METHOD__, array $options=[])
 Commit changes and clear view snapshots on all primary connections. More...
 
 destroy ()
 Close all connections and make further attempts to open connections result in DBAccessError. More...
 
 disableChronologyProtection ()
 Disable the ChronologyProtector on all instantiated tracked load balancer instances. More...
 
 flushReplicaSnapshots ( $fname=__METHOD__)
 Commit all replica DB transactions so as to flush any REPEATABLE-READ or SSI snapshot. More...
 
 forEachLB ( $callback, array $params=[])
 Execute a function for each instantiated tracked load balancer instance. More...
 
 getAllExternalLBs ()
 Get the tracked load balancer instances for all external clusters. More...
 
 getAllMainLBs ()
 Get the tracked load balancer instances for all main clusters. More...
 
 getChronologyProtectorClientId ()
 Get the client ID of the ChronologyProtector instance. More...
 
 getChronologyProtectorTouched ( $domain=false)
 Get the UNIX timestamp when the client last touched the DB, if they did so recently. More...
 
 getEmptyTransactionTicket ( $fname)
 Get a token asserting that no transaction writes are active on tracked load balancers. More...
 
 getExternalLB ( $cluster)
 Get the tracked load balancer instance for an external cluster. More...
 
 getLocalDomainID ()
 Get the local (and default) database domain ID of connection handles. More...
 
 getMainLB ( $domain=false)
 Get the tracked load balancer instance for a main cluster. More...
 
 getTransactionProfiler ()
 Get the TransactionProfiler used by this instance. More...
 
 hasMasterChanges ()
 
 hasOrMadeRecentMasterChanges ( $age=null)
 
 hasOrMadeRecentPrimaryChanges ( $age=null)
 Determine if any primary connection has pending/written changes from this request. More...
 
 hasPrimaryChanges ()
 Determine if any primary connection has pending changes. More...
 
 hasTransactionRound ()
 Check if an explicit transaction round is active. More...
 
 isReadyForRoundOperations ()
 Check if transaction rounds can be started, committed, or rolled back right now. More...
 
 laggedReplicaUsed ()
 Detemine if any lagged replica DB connection was used. More...
 
 newExternalLB ( $cluster, $owner=null)
 Create a new load balancer instance for an external cluster. More...
 
 newMainLB ( $domain=false, $owner=null)
 Create a new load balancer instance for a main cluster. More...
 
 redefineLocalDomain ( $domain)
 Close all connections and redefine the local domain for testing or schema creation. More...
 
 resolveDomainID ( $domain)
 
 rollbackMasterChanges ( $fname=__METHOD__)
 
 rollbackPrimaryChanges ( $fname=__METHOD__)
 Rollback changes on all primary connections. More...
 
 setAgentName ( $agent)
 
 setDefaultReplicationWaitTimeout ( $seconds)
 Set the default timeout for replication wait checks. More...
 
 setDomainAliases (array $aliases)
 Convert certain database domains to alternative ones. More...
 
 setIndexAliases (array $aliases)
 Convert certain index names to alternative names before querying the DB. More...
 
 setLocalDomainPrefix ( $prefix)
 Set a new table prefix for the existing local domain ID for testing. More...
 
 setRequestInfo (array $info)
 Inject HTTP request header/cookie information during setup of this instance. More...
 
 setTableAliases (array $aliases)
 Make certain table names use their own database, schema, and table prefix when passed into SQL queries pre-escaped and without a qualified database name. More...
 
 setWaitForReplicationListener ( $name, callable $callback=null)
 Add a callback to be run in every call to waitForReplication() before waiting. More...
 
 shutdown ( $flags=self::SHUTDOWN_NORMAL, callable $workCallback=null, &$cpIndex=null, &$cpClientId=null)
 Prepare all instantiated tracked load balancer instances for shutdown. More...
 
 waitForReplication (array $opts=[])
 Waits for the replica DBs to catch up to the current primary position. More...
 

Public Attributes

const SHUTDOWN_NO_CHRONPROT = 1
 Do not save "session consistency" DB replication positions. More...
 
const SHUTDOWN_NORMAL = 0
 Idion for "no special shutdown flags". More...
 

Detailed Description

An interface for generating database load balancers.

Since
1.28

Definition at line 33 of file ILBFactory.php.

Constructor & Destructor Documentation

◆ __construct()

Wikimedia\Rdbms\ILBFactory::__construct ( array  $conf)

Construct a manager of ILoadBalancer instances.

Sub-classes will extend the required keys in $conf with additional parameters

Parameters
array$confArray with keys:
  • localDomain: A DatabaseDomain or domain ID string.
  • readOnlyReason: Reason the primary DB is read-only if so [optional]
  • srvCache: BagOStuff instance for server cache [optional]
  • cpStash: BagOStuff instance for ChronologyProtector store [optional] See ChronologyProtector requirements.
  • wanCache: WANObjectCache instance [optional]
  • cliMode: Whether the execution context is a CLI script. [optional]
  • maxLag: Try to avoid DB replicas with lag above this many seconds [optional]
  • profiler: Class name or instance with profileIn()/profileOut() methods. [optional]
  • trxProfiler: TransactionProfiler instance. [optional]
  • replLogger: PSR-3 logger instance. [optional]
  • connLogger: PSR-3 logger instance. [optional]
  • queryLogger: PSR-3 logger instance. [optional]
  • perfLogger: PSR-3 logger instance. [optional]
  • errorLogger: Callback that takes an Exception and logs it. [optional]
  • deprecationLogger: Callback to log a deprecation warning. [optional]
  • secret: Secret string to use for HMAC hashing [optional]
  • criticalSectionProvider: CriticalSectionProvider instance [optional]
Exceptions
InvalidArgumentException

Implemented in Wikimedia\Rdbms\LBFactorySingle, Wikimedia\Rdbms\LBFactorySimple, Wikimedia\Rdbms\LBFactoryMulti, and Wikimedia\Rdbms\LBFactory.

Member Function Documentation

◆ appendShutdownCPIndexAsQuery()

Wikimedia\Rdbms\ILBFactory::appendShutdownCPIndexAsQuery (   $url,
  $index 
)

Append ?cpPosIndex parameter to a URL for ChronologyProtector purposes if needed.

Note that unlike cookies, this works across domains.

Parameters
string$url
int$indexWrite counter index
Returns
string

Implemented in Wikimedia\Rdbms\LBFactory.

◆ beginMasterChanges()

Wikimedia\Rdbms\ILBFactory::beginMasterChanges (   $fname = __METHOD__)
Deprecated:
since 1.37 Use beginPrimaryChanges() instead.
Parameters
string$fname
Exceptions
DBTransactionError

Implemented in Wikimedia\Rdbms\LBFactory.

◆ beginPrimaryChanges()

Wikimedia\Rdbms\ILBFactory::beginPrimaryChanges (   $fname = __METHOD__)

Flush any primary transaction snapshots and set DBO_TRX (if DBO_DEFAULT is set)

The DBO_TRX setting will be reverted to the default in each of these methods:

This only applies to the tracked load balancer instances.

This allows for custom transaction rounds from any outer transaction scope.

Parameters
string$fname
Exceptions
DBTransactionError
Since
1.37

Implemented in Wikimedia\Rdbms\LBFactory.

Referenced by DeferredUpdates\attemptUpdate().

◆ closeAll()

Wikimedia\Rdbms\ILBFactory::closeAll ( )

Close all connections on instantiated tracked load balancer instances.

Implemented in Wikimedia\Rdbms\LBFactory.

◆ commitAll()

Wikimedia\Rdbms\ILBFactory::commitAll (   $fname = __METHOD__,
array  $options = [] 
)

Commit open transactions on all connections.

This only applies to the instantiated tracked load balancer instances.

This is useful for two main cases:

  • a) Committing changes to the masters
  • b) Releasing the snapshot on all connections, primary and replica DBs
Parameters
string$fnameCaller name
array$optionsOptions map:
  • maxWriteDuration: abort if more than this much time was spent in write queries

Implemented in Wikimedia\Rdbms\LBFactory.

◆ commitAndWaitForReplication()

Wikimedia\Rdbms\ILBFactory::commitAndWaitForReplication (   $fname,
  $ticket,
array  $opts = [] 
)

Call commitPrimaryChanges() and waitForReplication() if $ticket indicates it is safe.

The ticket is used to check that the caller owns the transaction round or can act on behalf of the caller that owns the transaction round.

See also
commitPrimaryChanges()
waitForReplication()
Parameters
string$fnameCaller name (e.g. METHOD)
mixed$ticketResult of getEmptyTransactionTicket()
array$optsOptions to waitForReplication()
Returns
bool True if the wait was successful, false on timeout

Implemented in Wikimedia\Rdbms\LBFactory.

◆ commitMasterChanges()

Wikimedia\Rdbms\ILBFactory::commitMasterChanges (   $fname = __METHOD__,
array  $options = [] 
)
Deprecated:
since 1.37; please use commitPrimaryChanges() instead.
Parameters
string$fnameCaller name
array$optionsOptions map:
  • maxWriteDuration: abort if more than this much time was spent in write queries
Exceptions
DBTransactionError

Implemented in Wikimedia\Rdbms\LBFactory.

◆ commitPrimaryChanges()

Wikimedia\Rdbms\ILBFactory::commitPrimaryChanges (   $fname = __METHOD__,
array  $options = [] 
)

Commit changes and clear view snapshots on all primary connections.

This only applies to the instantiated tracked load balancer instances.

Parameters
string$fnameCaller name
array$optionsOptions map:
  • maxWriteDuration: abort if more than this much time was spent in write queries
Exceptions
DBTransactionError
Since
1.37

Implemented in Wikimedia\Rdbms\LBFactory.

Referenced by DeferredUpdates\attemptUpdate().

◆ destroy()

Wikimedia\Rdbms\ILBFactory::destroy ( )

Close all connections and make further attempts to open connections result in DBAccessError.

This only applies to the tracked load balancer instances.

See also
ILoadBalancer::disable()

Implemented in Wikimedia\Rdbms\LBFactory.

◆ disableChronologyProtection()

Wikimedia\Rdbms\ILBFactory::disableChronologyProtection ( )

Disable the ChronologyProtector on all instantiated tracked load balancer instances.

This can be called at the start of special API entry points.

Implemented in Wikimedia\Rdbms\LBFactory.

◆ flushReplicaSnapshots()

Wikimedia\Rdbms\ILBFactory::flushReplicaSnapshots (   $fname = __METHOD__)

Commit all replica DB transactions so as to flush any REPEATABLE-READ or SSI snapshot.

This only applies to the instantiated tracked load balancer instances.

This is useful for getting rid of stale data from an implicit transaction round

Parameters
string$fnameCaller name

Implemented in Wikimedia\Rdbms\LBFactory.

◆ forEachLB()

◆ getAllExternalLBs()

Wikimedia\Rdbms\ILBFactory::getAllExternalLBs ( )

Get the tracked load balancer instances for all external clusters.

If no tracked instance exists for a cluster, then one will be instantiated

Returns
ILoadBalancer[] Map of (cluster name => ILoadBalancer)
Since
1.29

Implemented in Wikimedia\Rdbms\LBFactorySingle, Wikimedia\Rdbms\LBFactorySimple, and Wikimedia\Rdbms\LBFactoryMulti.

◆ getAllMainLBs()

Wikimedia\Rdbms\ILBFactory::getAllMainLBs ( )

Get the tracked load balancer instances for all main clusters.

If no tracked instance exists for a cluster, then one will be instantiated

Note that default main cluster name is ILoadBalancer::CLUSTER_MAIN_DEFAULT

Returns
ILoadBalancer[] Map of (cluster name => ILoadBalancer)
Since
1.29

Implemented in Wikimedia\Rdbms\LBFactorySingle, Wikimedia\Rdbms\LBFactorySimple, and Wikimedia\Rdbms\LBFactoryMulti.

◆ getChronologyProtectorClientId()

Wikimedia\Rdbms\ILBFactory::getChronologyProtectorClientId ( )

Get the client ID of the ChronologyProtector instance.

Returns
string Client ID
Since
1.34

Implemented in Wikimedia\Rdbms\LBFactory.

◆ getChronologyProtectorTouched()

Wikimedia\Rdbms\ILBFactory::getChronologyProtectorTouched (   $domain = false)

Get the UNIX timestamp when the client last touched the DB, if they did so recently.

Parameters
DatabaseDomain | string | bool$domainDomain ID, or false for the current domain
Returns
float|false UNIX timestamp; false if not recent or on record

Implemented in Wikimedia\Rdbms\LBFactory.

◆ getEmptyTransactionTicket()

Wikimedia\Rdbms\ILBFactory::getEmptyTransactionTicket (   $fname)

Get a token asserting that no transaction writes are active on tracked load balancers.

Parameters
string$fnameCaller name (e.g. METHOD)
Returns
mixed A value to pass to commitAndWaitForReplication()

Implemented in Wikimedia\Rdbms\LBFactory.

Referenced by DeferredUpdates\attemptUpdate().

◆ getExternalLB()

Wikimedia\Rdbms\ILBFactory::getExternalLB (   $cluster)

Get the tracked load balancer instance for an external cluster.

If no tracked instances exists, then one will be instantiated

Parameters
string$clusterExternal cluster name
Returns
ILoadBalancer

Implemented in Wikimedia\Rdbms\LBFactorySingle, Wikimedia\Rdbms\LBFactorySimple, and Wikimedia\Rdbms\LBFactoryMulti.

Referenced by Wikimedia\Rdbms\LBFactory\waitForReplication().

◆ getLocalDomainID()

Wikimedia\Rdbms\ILBFactory::getLocalDomainID ( )

Get the local (and default) database domain ID of connection handles.

See also
DatabaseDomain
Returns
string Database domain ID; this specifies DB name, schema, and table prefix
Since
1.32

Implemented in Wikimedia\Rdbms\LBFactory.

Referenced by MWLBFactory\setDomainAliases().

◆ getMainLB()

Wikimedia\Rdbms\ILBFactory::getMainLB (   $domain = false)

Get the tracked load balancer instance for a main cluster.

If no tracked instances exists, then one will be instantiated

Parameters
bool | string$domainDomain ID, or false for the current domain
Returns
ILoadBalancer

Implemented in Wikimedia\Rdbms\LBFactorySingle, Wikimedia\Rdbms\LBFactorySimple, and Wikimedia\Rdbms\LBFactoryMulti.

Referenced by MediaWiki\User\UserGroupManager\__construct(), WatchedItemStore\__construct(), MWLBFactory\applyGlobalState(), Wikimedia\Rdbms\LBFactory\getChronologyProtectorTouched(), and Wikimedia\Rdbms\LBFactory\waitForReplication().

◆ getTransactionProfiler()

Wikimedia\Rdbms\ILBFactory::getTransactionProfiler ( )

Get the TransactionProfiler used by this instance.

Returns
TransactionProfiler
Since
1.35

Implemented in Wikimedia\Rdbms\LBFactory.

◆ hasMasterChanges()

Wikimedia\Rdbms\ILBFactory::hasMasterChanges ( )
Deprecated:
since 1.37; please use hasPrimaryChanges() instead.
Returns
bool

Implemented in Wikimedia\Rdbms\LBFactory.

◆ hasOrMadeRecentMasterChanges()

Wikimedia\Rdbms\ILBFactory::hasOrMadeRecentMasterChanges (   $age = null)
Deprecated:
since 1.37; please use hasOrMadeRecentPrimaryChanges() instead.
Parameters
float | null$ageHow many seconds ago is "recent" [defaults to LB lag wait timeout]
Returns
bool

Implemented in Wikimedia\Rdbms\LBFactory.

◆ hasOrMadeRecentPrimaryChanges()

Wikimedia\Rdbms\ILBFactory::hasOrMadeRecentPrimaryChanges (   $age = null)

Determine if any primary connection has pending/written changes from this request.

This only applies to the instantiated tracked load balancer instances.

Parameters
float | null$ageHow many seconds ago is "recent" [defaults to LB lag wait timeout]
Returns
bool

Implemented in Wikimedia\Rdbms\LBFactory.

◆ hasPrimaryChanges()

Wikimedia\Rdbms\ILBFactory::hasPrimaryChanges ( )

Determine if any primary connection has pending changes.

This only applies to the instantiated tracked load balancer instances.

Returns
bool
Since
1.37

Implemented in Wikimedia\Rdbms\LBFactory.

◆ hasTransactionRound()

Wikimedia\Rdbms\ILBFactory::hasTransactionRound ( )

Check if an explicit transaction round is active.

Returns
bool
Since
1.29

Implemented in Wikimedia\Rdbms\LBFactory.

Referenced by DeferredUpdates\attemptUpdate().

◆ isReadyForRoundOperations()

Wikimedia\Rdbms\ILBFactory::isReadyForRoundOperations ( )

Check if transaction rounds can be started, committed, or rolled back right now.

This can be used as a recusion guard to avoid exceptions in transaction callbacks.

Returns
bool
Since
1.32

Implemented in Wikimedia\Rdbms\LBFactory.

◆ laggedReplicaUsed()

Wikimedia\Rdbms\ILBFactory::laggedReplicaUsed ( )

Detemine if any lagged replica DB connection was used.

This only applies to the instantiated tracked load balancer instances.

Returns
bool

Implemented in Wikimedia\Rdbms\LBFactory.

◆ newExternalLB()

Wikimedia\Rdbms\ILBFactory::newExternalLB (   $cluster,
  $owner = null 
)

Create a new load balancer instance for an external cluster.

The resulting object will be untracked and the caller is responsible for cleaning it up. Database replication positions will not be saved by ChronologyProtector.

This method is for only advanced usage and callers should almost always use getExternalLB() instead. This method can be useful when a table is used as a key/value store. In that cases, one might want to query it in autocommit mode (DBO_TRX off) but still use DBO_TRX transaction rounds on other tables.

Parameters
string$clusterExternal cluster name
int | null$ownerOwner ID of the new instance (e.g. this LBFactory ID)
Returns
ILoadBalancer

Implemented in Wikimedia\Rdbms\LBFactorySingle, Wikimedia\Rdbms\LBFactorySimple, and Wikimedia\Rdbms\LBFactoryMulti.

◆ newMainLB()

Wikimedia\Rdbms\ILBFactory::newMainLB (   $domain = false,
  $owner = null 
)

Create a new load balancer instance for a main cluster.

The resulting object will be untracked and the caller is responsible for cleaning it up. Database replication positions will not be saved by ChronologyProtector.

This method is for only advanced usage and callers should almost always use getMainLB() instead. This method can be useful when a table is used as a key/value store. In that cases, one might want to query it in autocommit mode (DBO_TRX off) but still use DBO_TRX transaction rounds on other tables.

Parameters
bool | string$domainDomain ID, or false for the current domain
int | null$ownerOwner ID of the new instance (e.g. this LBFactory ID)
Returns
ILoadBalancer

Implemented in Wikimedia\Rdbms\LBFactorySingle, Wikimedia\Rdbms\LBFactorySimple, and Wikimedia\Rdbms\LBFactoryMulti.

◆ redefineLocalDomain()

Wikimedia\Rdbms\ILBFactory::redefineLocalDomain (   $domain)

Close all connections and redefine the local domain for testing or schema creation.

This only applies to the tracked load balancer instances.

Parameters
DatabaseDomain | string$domain
Since
1.33

Implemented in Wikimedia\Rdbms\LBFactory.

◆ resolveDomainID()

Wikimedia\Rdbms\ILBFactory::resolveDomainID (   $domain)
Parameters
DatabaseDomain | string | bool$domainDatabase domain
Returns
string Value of $domain if provided or the local domain otherwise
Since
1.32

Implemented in Wikimedia\Rdbms\LBFactory.

◆ rollbackMasterChanges()

Wikimedia\Rdbms\ILBFactory::rollbackMasterChanges (   $fname = __METHOD__)
Deprecated:
since 1.37; please use rollbackPrimaryChanges() instead.
Parameters
string$fnameCaller name

Implemented in Wikimedia\Rdbms\LBFactory.

◆ rollbackPrimaryChanges()

Wikimedia\Rdbms\ILBFactory::rollbackPrimaryChanges (   $fname = __METHOD__)

Rollback changes on all primary connections.

This only applies to the instantiated tracked load balancer instances.

Parameters
string$fnameCaller name
Since
1.37

Implemented in Wikimedia\Rdbms\LBFactory.

Referenced by DeferredUpdates\run().

◆ setAgentName()

Wikimedia\Rdbms\ILBFactory::setAgentName (   $agent)
Parameters
string$agentAgent name for query profiling

Implemented in Wikimedia\Rdbms\LBFactory.

Referenced by MWLBFactory\applyGlobalState().

◆ setDefaultReplicationWaitTimeout()

Wikimedia\Rdbms\ILBFactory::setDefaultReplicationWaitTimeout (   $seconds)

Set the default timeout for replication wait checks.

Parameters
int$secondsTimeout, in seconds
Returns
int The previous default timeout
Since
1.35

Implemented in Wikimedia\Rdbms\LBFactory.

◆ setDomainAliases()

Wikimedia\Rdbms\ILBFactory::setDomainAliases ( array  $aliases)

Convert certain database domains to alternative ones.

This can be used for backwards compatibility logic.

Parameters
DatabaseDomain[] | string[]$aliasesMap of (domain alias => domain)
Since
1.35

Implemented in Wikimedia\Rdbms\LBFactory.

Referenced by MWLBFactory\setDomainAliases().

◆ setIndexAliases()

Wikimedia\Rdbms\ILBFactory::setIndexAliases ( array  $aliases)

Convert certain index names to alternative names before querying the DB.

Note that this applies to indexes regardless of the table they belong to.

This can be employed when an index was renamed X => Y in code, but the new Y-named indexes were not yet built on all DBs. After all the Y-named ones are added by the DBA, the aliases can be removed, and then the old X-named indexes dropped.

Parameters
string[]$aliasesMap of (index alias => index name)
Since
1.31

Implemented in Wikimedia\Rdbms\LBFactory.

◆ setLocalDomainPrefix()

Wikimedia\Rdbms\ILBFactory::setLocalDomainPrefix (   $prefix)

Set a new table prefix for the existing local domain ID for testing.

Parameters
string$prefix
Since
1.33

Implemented in Wikimedia\Rdbms\LBFactory.

◆ setRequestInfo()

Wikimedia\Rdbms\ILBFactory::setRequestInfo ( array  $info)

Inject HTTP request header/cookie information during setup of this instance.

Parameters
array$infoMap of fields, including:
  • IPAddress : IP address
  • UserAgent : User-Agent HTTP header
  • ChronologyProtection : cookie/header value specifying ChronologyProtector usage
  • ChronologyPositionIndex: timestamp used to get up-to-date DB positions for the agent

Implemented in Wikimedia\Rdbms\LBFactory.

Referenced by MWLBFactory\applyGlobalState().

◆ setTableAliases()

Wikimedia\Rdbms\ILBFactory::setTableAliases ( array  $aliases)

Make certain table names use their own database, schema, and table prefix when passed into SQL queries pre-escaped and without a qualified database name.

For example, "user" can be converted to "myschema.mydbname.user" for convenience. Appearances like user, somedb.user, somedb.someschema.user will used literally.

Calling this twice will completely clear any old table aliases. Also, note that callers are responsible for making sure the schemas and databases actually exist.

Parameters
array[]$aliasesMap of (table => (dbname, schema, prefix) map)
Since
1.31

Implemented in Wikimedia\Rdbms\LBFactory.

◆ setWaitForReplicationListener()

Wikimedia\Rdbms\ILBFactory::setWaitForReplicationListener (   $name,
callable  $callback = null 
)

Add a callback to be run in every call to waitForReplication() before waiting.

Callbacks must clear any transactions that they start.

Parameters
string$nameCallback name
callable | null$callbackUse null to unset a callback

Implemented in Wikimedia\Rdbms\LBFactory.

Referenced by MWLBFactory\applyGlobalState().

◆ shutdown()

Wikimedia\Rdbms\ILBFactory::shutdown (   $flags = self::SHUTDOWN_NORMAL,
callable  $workCallback = null,
$cpIndex = null,
$cpClientId = null 
)

Prepare all instantiated tracked load balancer instances for shutdown.

Parameters
int$flagsBit field of ILBFactory::SHUTDOWN_* constants
callable | null$workCallbackWork to mask ChronologyProtector writes
int | null&$cpIndexPosition key write counter for ChronologyProtector [returned]
string | null&$cpClientIdClient ID hash for ChronologyProtector [returned]

Implemented in Wikimedia\Rdbms\LBFactory.

◆ waitForReplication()

Wikimedia\Rdbms\ILBFactory::waitForReplication ( array  $opts = [])

Waits for the replica DBs to catch up to the current primary position.

Use this when updating very large numbers of rows, as in maintenance scripts, to avoid causing too much lag. Of course, this is a no-op if there are no replica DBs.

By default this waits on all DB clusters actually used in this request. This makes sense when lag being waiting on is caused by the code that does this check. In that case, setting "ifWritesSince" can avoid the overhead of waiting for clusters that were not changed since the last wait check. To forcefully wait on a specific cluster for a given domain, use the 'domain' parameter. To forcefully wait on an "external" cluster, use the "cluster" parameter.

Never call this function after a large DB write that is still in a transaction. It only makes sense to call this after the possible lag inducing changes were committed.

This only applies to the instantiated tracked load balancer instances.

Parameters
array$optsOptional fields that include:
  • domain: Wait on the load balancer DBs that handles the given domain ID.
  • cluster: Wait on the given external load balancer DBs.
  • timeout: Max wait time. Default: 60 seconds for CLI, 1 second for web.
  • ifWritesSince: Only wait if writes were done since this UNIX timestamp.
Returns
bool True on success, false if a timeout or error occurred while waiting

Implemented in Wikimedia\Rdbms\LBFactory.

Referenced by RebuildRecentchanges\rebuildRecentChangesTablePass1(), RebuildRecentchanges\rebuildRecentChangesTablePass2(), RebuildRecentchanges\rebuildRecentChangesTablePass3(), RebuildRecentchanges\rebuildRecentChangesTablePass4(), and RebuildRecentchanges\rebuildRecentChangesTablePass5().

Member Data Documentation

◆ SHUTDOWN_NO_CHRONPROT

const Wikimedia\Rdbms\ILBFactory::SHUTDOWN_NO_CHRONPROT = 1

Do not save "session consistency" DB replication positions.

Definition at line 37 of file ILBFactory.php.

◆ SHUTDOWN_NORMAL

const Wikimedia\Rdbms\ILBFactory::SHUTDOWN_NORMAL = 0

Idion for "no special shutdown flags".

Definition at line 35 of file ILBFactory.php.


The documentation for this interface was generated from the following file: