MediaWiki  REL1_28
LBFactory Class Reference

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

Inheritance diagram for LBFactory:
Collaboration diagram for LBFactory:

Public Member Functions

 __construct (array $conf)
 Construct a manager of ILoadBalancer objects. More...
 
 __destruct ()
 
 appendPreShutdownTimeAsQuery ( $url, $time)
 Append ?cpPosTime parameter to a URL for ChronologyProtector purposes if needed. More...
 
 beginMasterChanges ( $fname=__METHOD__)
 Flush any master transaction snapshots and set DBO_TRX (if DBO_DEFAULT is set) More...
 
 closeAll ()
 Close all open database connections on all open load balancers. More...
 
 commitAll ( $fname=__METHOD__, array $options=[])
 Commit open transactions on all connections. More...
 
 commitAndWaitForReplication ( $fname, $ticket, array $opts=[])
 Convenience method for safely running commitMasterChanges()/waitForReplication() More...
 
 commitMasterChanges ( $fname=__METHOD__, array $options=[])
 Commit changes on all master connections. More...
 
 destroy ()
 Disables all load balancers. More...
 
 disableChronologyProtection ()
 Disable the ChronologyProtector for all load balancers. More...
 
 flushReplicaSnapshots ( $fname=__METHOD__)
 Commit all replica DB transactions so as to flush any REPEATABLE-READ or SSI snapshot. More...
 
 getChronologyProtectorTouched ( $dbName)
 
 getEmptyTransactionTicket ( $fname)
 Get a token asserting that no transaction writes are active. More...
 
 getExternalLB ( $cluster)
 
 getMainLB ( $domain=false)
 
 hasMasterChanges ()
 Determine if any master connection has pending changes. More...
 
 hasOrMadeRecentMasterChanges ( $age=null)
 Determine if any master connection has pending/written changes from this request. More...
 
 hasTransactionRound ()
 Check if a transaction round is active. More...
 
 laggedReplicaUsed ()
 Detemine if any lagged replica DB connection was used. More...
 
 newExternalLB ( $cluster)
 
 newMainLB ( $domain=false)
 
 rollbackMasterChanges ( $fname=__METHOD__)
 Rollback changes on all master connections. More...
 
 setAgentName ( $agent)
 
 setDomainPrefix ( $prefix)
 Set a new table prefix for the existing local domain ID for testing. More...
 
 setRequestInfo (array $info)
 
 setWaitForReplicationListener ( $name, callable $callback=null)
 Add a callback to be run in every call to waitForReplication() before waiting. More...
 
 shutdown ( $mode=self::SHUTDOWN_CHRONPROT_SYNC, callable $workCallback=null)
 Prepare all tracked load balancers for shutdown. More...
 
 waitForReplication (array $opts=[])
 Waits for the replica DBs to catch up to the current master position. More...
 
- Public Member Functions inherited from ILBFactory
 forEachLB ( $callback, array $params=[])
 Execute a function for each tracked load balancer The callback is called with the load balancer as the first parameter, and $params passed as the subsequent parameters. More...
 

Protected Member Functions

 baseLoadBalancerParams ()
 Base parameters to LoadBalancer::__construct() More...
 
 forEachLBCallMethod ( $methodName, array $args=[])
 Call a method of each tracked load balancer. More...
 
 getChronologyProtector ()
 
 getScopedPHPBehaviorForCommit ()
 Make PHP ignore user aborts/disconnects until the returned value leaves scope. More...
 
 initLoadBalancer (ILoadBalancer $lb)
 
 shutdownChronologyProtector (ChronologyProtector $cp, $workCallback, $mode)
 Get and record all of the staged DB positions into persistent memory storage. More...
 

Protected Attributes

string $agent
 Agent name for query profiling. More...
 
ChronologyProtector $chronProt
 
bool $cliMode
 Whether this PHP instance is for a CLI script. More...
 
LoggerInterface $connLogger
 
callable $errorLogger
 Error logger. More...
 
string $hostname
 Local hostname of the app server. More...
 
DatabaseDomain $localDomain
 Local domain. More...
 
BagOStuff $memCache
 
LoggerInterface $perfLogger
 
object string $profiler
 Class name or object With profileIn/profileOut methods. More...
 
LoggerInterface $queryLogger
 
string bool $readOnlyReason = false
 Reason all LBs are read-only or false if not. More...
 
callable[] $replicationWaitCallbacks = []
 
LoggerInterface $replLogger
 
array $requestInfo
 Web request information about the client. More...
 
BagOStuff $srvCache
 
mixed $ticket
 
TransactionProfiler $trxProfiler
 
string bool $trxRoundId = false
 String if a requested DBO_TRX transaction round is active. More...
 
WANObjectCache $wanCache
 

Private Member Functions

 logIfMultiDbTransaction ()
 Log query info if multi DB transactions are going to be committed now. More...
 

Static Private Attributes

static $loggerFields
 

Additional Inherited Members

- Public Attributes inherited from ILBFactory
const SHUTDOWN_CHRONPROT_ASYNC = 1
 
const SHUTDOWN_CHRONPROT_SYNC = 2
 
const SHUTDOWN_NO_CHRONPROT = 0
 

Detailed Description

An interface for generating database load balancers.

Definition at line 31 of file LBFactory.php.

Constructor & Destructor Documentation

◆ __construct()

LBFactory::__construct ( array  $conf)

Construct a manager of ILoadBalancer objects.

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

Parameters
$conf$params Array with keys:
  • localDomain: A DatabaseDomain or domain ID string.
  • readOnlyReason : Reason the master DB is read-only if so [optional]
  • srvCache : BagOStuff object for server cache [optional]
  • memCache : BagOStuff object for cluster memory cache [optional]
  • wanCache : WANObjectCache object [optional]
  • hostname : The name of the current server [optional]
  • cliMode: Whether the execution context is a CLI script. [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]
Exceptions
InvalidArgumentException

Implements ILBFactory.

Reimplemented in LBFactoryMulti, LBFactorySimple, and LBFactorySingle.

Definition at line 79 of file LBFactory.php.

References $e, $params, as, WANObjectCache\newEmpty(), DatabaseDomain\newFromId(), and DatabaseDomain\newUnspecified().

◆ __destruct()

LBFactory::__destruct ( )

Definition at line 571 of file LBFactory.php.

References destroy().

Member Function Documentation

◆ appendPreShutdownTimeAsQuery()

LBFactory::appendPreShutdownTimeAsQuery (   $url,
  $time 
)

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

Note that unlike cookies, this works accross domains

Parameters
string$url
float$timeUNIX timestamp just before shutdown() was called
Returns
string

Implements ILBFactory.

Definition at line 537 of file LBFactory.php.

References ILBFactory\forEachLB(), ILoadBalancer\getServerCount(), and use.

◆ baseLoadBalancerParams()

LBFactory::baseLoadBalancerParams ( )
finalprotected

◆ beginMasterChanges()

LBFactory::beginMasterChanges (   $fname = __METHOD__)

Flush any master 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 allows for custom transaction rounds from any outer transaction scope.

Parameters
string$fname
Exceptions
DBTransactionError

Implements ILBFactory.

Definition at line 191 of file LBFactory.php.

References $fname, and forEachLBCallMethod().

Referenced by commitAndWaitForReplication().

◆ closeAll()

LBFactory::closeAll ( )

Close all open database connections on all open load balancers.

Implements ILBFactory.

Definition at line 529 of file LBFactory.php.

References forEachLBCallMethod().

◆ commitAll()

LBFactory::commitAll (   $fname = __METHOD__,
array  $options = [] 
)

Commit open transactions on all connections.

This is useful for two main cases:

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

Implements ILBFactory.

Definition at line 186 of file LBFactory.php.

References $fname, $options, commitMasterChanges(), and forEachLBCallMethod().

◆ commitAndWaitForReplication()

LBFactory::commitAndWaitForReplication (   $fname,
  $ticket,
array  $opts = [] 
)

Convenience method for safely running commitMasterChanges()/waitForReplication()

This will commit and wait unless $ticket indicates it is unsafe to do so

Parameters
string$fnameCaller name (e.g. METHOD)
mixed$ticketResult of getEmptyTransactionTicket()
array$optsOptions to waitForReplication()
Exceptions
DBReplicationWaitError

Implements ILBFactory.

Definition at line 387 of file LBFactory.php.

References $fname, $ticket, $trxRoundId, beginMasterChanges(), commitMasterChanges(), and waitForReplication().

◆ commitMasterChanges()

LBFactory::commitMasterChanges (   $fname = __METHOD__,
array  $options = [] 
)

Commit changes on all master connections.

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

Implements ILBFactory.

Definition at line 203 of file LBFactory.php.

References $e, $fname, $options, ILBFactory\forEachLB(), forEachLBCallMethod(), getScopedPHPBehaviorForCommit(), logIfMultiDbTransaction(), ILoadBalancer\runMasterPostTrxCallbacks(), and use.

Referenced by commitAll(), commitAndWaitForReplication(), and shutdown().

◆ destroy()

LBFactory::destroy ( )

Disables all load balancers.

All connections are closed, and any attempt to open a new connection will result in a DBAccessError.

See also
ILoadBalancer::disable()

Implements ILBFactory.

Definition at line 121 of file LBFactory.php.

References forEachLBCallMethod(), and shutdown().

Referenced by __destruct().

◆ disableChronologyProtection()

LBFactory::disableChronologyProtection ( )

Disable the ChronologyProtector for all load balancers.

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

Implements ILBFactory.

Definition at line 417 of file LBFactory.php.

References getChronologyProtector().

◆ flushReplicaSnapshots()

LBFactory::flushReplicaSnapshots (   $fname = __METHOD__)

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

Parameters
string$fnameCaller name

Implements ILBFactory.

Definition at line 182 of file LBFactory.php.

References $fname, and forEachLBCallMethod().

◆ forEachLBCallMethod()

LBFactory::forEachLBCallMethod (   $methodName,
array  $args = [] 
)
protected

Call a method of each tracked load balancer.

Parameters
string$methodName
array$args

Definition at line 173 of file LBFactory.php.

References $args, array(), and ILBFactory\forEachLB().

Referenced by beginMasterChanges(), closeAll(), commitAll(), commitMasterChanges(), destroy(), flushReplicaSnapshots(), and rollbackMasterChanges().

◆ getChronologyProtector()

◆ getChronologyProtectorTouched()

LBFactory::getChronologyProtectorTouched (   $dbName)
Parameters
string$dbNameDB master name (e.g. "db1052")
Returns
float|bool UNIX timestamp when client last touched the DB or false if not recent

Implements ILBFactory.

Definition at line 413 of file LBFactory.php.

References getChronologyProtector().

◆ getEmptyTransactionTicket()

LBFactory::getEmptyTransactionTicket (   $fname)

Get a token asserting that no transaction writes are active.

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

Implements ILBFactory.

Definition at line 376 of file LBFactory.php.

References $ticket, and hasMasterChanges().

◆ getExternalLB()

LBFactory::getExternalLB (   $cluster)
abstract
See also
ILBFactory::getExternalLB()
Parameters
string$cluster
Returns
LoadBalancer

Implements ILBFactory.

Reimplemented in LBFactoryMulti, LBFactorySimple, and LBFactorySingle.

Referenced by waitForReplication().

◆ getMainLB()

LBFactory::getMainLB (   $domain = false)
abstract
See also
ILBFactory::getMainLB()
Parameters
bool$domain
Returns
LoadBalancer

Implements ILBFactory.

Reimplemented in LBFactoryMulti, LBFactorySimple, and LBFactorySingle.

Referenced by waitForReplication().

◆ getScopedPHPBehaviorForCommit()

LBFactory::getScopedPHPBehaviorForCommit ( )
finalprotected

Make PHP ignore user aborts/disconnects until the returned value leaves scope.

This returns null and does nothing in CLI mode.

Returns
ScopedCallback|null

Definition at line 560 of file LBFactory.php.

References use.

Referenced by commitMasterChanges().

◆ hasMasterChanges()

LBFactory::hasMasterChanges ( )

Determine if any master connection has pending changes.

Returns
bool

Implements ILBFactory.

Definition at line 273 of file LBFactory.php.

References $ret, ILBFactory\forEachLB(), ILoadBalancer\hasMasterChanges(), and use.

Referenced by getEmptyTransactionTicket().

◆ hasOrMadeRecentMasterChanges()

LBFactory::hasOrMadeRecentMasterChanges (   $age = null)

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

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

Implements ILBFactory.

Definition at line 291 of file LBFactory.php.

References $ret, ILBFactory\forEachLB(), ILoadBalancer\hasOrMadeRecentMasterChanges(), and use.

◆ hasTransactionRound()

LBFactory::hasTransactionRound ( )

Check if a transaction round is active.

Returns
bool
Since
1.28.3

Implements ILBFactory.

Definition at line 246 of file LBFactory.php.

◆ initLoadBalancer()

LBFactory::initLoadBalancer ( ILoadBalancer  $lb)
protected

◆ laggedReplicaUsed()

LBFactory::laggedReplicaUsed ( )

Detemine if any lagged replica DB connection was used.

Returns
bool

Implements ILBFactory.

Definition at line 282 of file LBFactory.php.

References $ret, ILBFactory\forEachLB(), ILoadBalancer\laggedReplicaUsed(), and use.

◆ logIfMultiDbTransaction()

LBFactory::logIfMultiDbTransaction ( )
private

Log query info if multi DB transactions are going to be committed now.

Definition at line 253 of file LBFactory.php.

References as, ILBFactory\forEachLB(), ILoadBalancer\getServerName(), ILoadBalancer\getWriterIndex(), ILoadBalancer\pendingMasterChangeCallers(), and use.

Referenced by commitMasterChanges().

◆ newExternalLB()

LBFactory::newExternalLB (   $cluster)
abstract
See also
ILBFactory::newExternalLB()
Parameters
string$cluster
Returns
LoadBalancer

Implements ILBFactory.

Reimplemented in LBFactoryMulti, LBFactorySimple, and LBFactorySingle.

◆ newMainLB()

LBFactory::newMainLB (   $domain = false)
abstract
See also
ILBFactory::newMainLB()
Parameters
bool$domain
Returns
LoadBalancer

Implements ILBFactory.

Reimplemented in LBFactoryMulti, LBFactorySimple, and LBFactorySingle.

◆ rollbackMasterChanges()

LBFactory::rollbackMasterChanges (   $fname = __METHOD__)

Rollback changes on all master connections.

Parameters
string$fnameCaller name

Implements ILBFactory.

Definition at line 236 of file LBFactory.php.

References $fname, ILBFactory\forEachLB(), forEachLBCallMethod(), and ILoadBalancer\runMasterPostTrxCallbacks().

◆ setAgentName()

LBFactory::setAgentName (   $agent)
Parameters
string$agentAgent name for query profiling

Implements ILBFactory.

Definition at line 533 of file LBFactory.php.

References $agent.

◆ setDomainPrefix()

LBFactory::setDomainPrefix (   $prefix)

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

Parameters
string$prefix

Implements ILBFactory.

Definition at line 517 of file LBFactory.php.

References ILBFactory\forEachLB(), ILoadBalancer\setDomainPrefix(), and use.

◆ setRequestInfo()

LBFactory::setRequestInfo ( array  $info)
Parameters
array$infoMap of fields, including:
  • IPAddress : IP address
  • UserAgent : User-Agent HTTP header
  • ChronologyProtection : cookie/header value specifying ChronologyProtector usage

Implements ILBFactory.

Definition at line 550 of file LBFactory.php.

References $requestInfo.

◆ setWaitForReplicationListener()

LBFactory::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

Implements ILBFactory.

Definition at line 368 of file LBFactory.php.

References $name.

◆ shutdown()

LBFactory::shutdown (   $mode = self::SHUTDOWN_CHRONPROT_SYNC,
callable  $workCallback = null 
)

Prepare all tracked load balancers for shutdown.

Parameters
integer$modeOne of the class SHUTDOWN_* constants
callable | null$workCallbackWork to mask ChronologyProtector writes

Implements ILBFactory.

Definition at line 126 of file LBFactory.php.

References $chronProt, commitMasterChanges(), getChronologyProtector(), and shutdownChronologyProtector().

Referenced by destroy().

◆ shutdownChronologyProtector()

LBFactory::shutdownChronologyProtector ( ChronologyProtector  $cp,
  $workCallback,
  $mode 
)
protected

Get and record all of the staged DB positions into persistent memory storage.

Parameters
ChronologyProtector$cp
callable | null$workCallbackWork to do instead of waiting on syncing positions
string$modeOne of (sync, async); whether to wait on remote datacenters

Definition at line 460 of file LBFactory.php.

References ILBFactory\forEachLB(), ILoadBalancer\getServerName(), ILoadBalancer\getWriterIndex(), ChronologyProtector\shutdown(), ChronologyProtector\shutdownLB(), use, and ILoadBalancer\waitForAll().

Referenced by shutdown().

◆ waitForReplication()

LBFactory::waitForReplication ( array  $opts = [])

Waits for the replica DBs to catch up to the current master 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.

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
  • ifWritesSince: Only wait if writes were done since this UNIX timestamp
Exceptions
DBReplicationWaitErrorIf a timeout or error occured waiting on a DB cluster

Implements ILBFactory.

Definition at line 299 of file LBFactory.php.

References as, ILBFactory\forEachLB(), getExternalLB(), getMainLB(), and use.

Referenced by commitAndWaitForReplication().

Member Data Documentation

◆ $agent

string LBFactory::$agent
protected

Agent name for query profiling.

Definition at line 74 of file LBFactory.php.

Referenced by baseLoadBalancerParams(), and setAgentName().

◆ $chronProt

ChronologyProtector LBFactory::$chronProt
protected

Definition at line 33 of file LBFactory.php.

Referenced by getChronologyProtector(), and shutdown().

◆ $cliMode

bool LBFactory::$cliMode
protected

Whether this PHP instance is for a CLI script.

Definition at line 72 of file LBFactory.php.

Referenced by baseLoadBalancerParams().

◆ $connLogger

LoggerInterface LBFactory::$connLogger
protected

Definition at line 41 of file LBFactory.php.

Referenced by baseLoadBalancerParams().

◆ $errorLogger

callable LBFactory::$errorLogger
protected

Error logger.

Definition at line 47 of file LBFactory.php.

Referenced by baseLoadBalancerParams().

◆ $hostname

string LBFactory::$hostname
protected

Local hostname of the app server.

Definition at line 58 of file LBFactory.php.

Referenced by baseLoadBalancerParams().

◆ $localDomain

DatabaseDomain LBFactory::$localDomain
protected

Local domain.

Definition at line 56 of file LBFactory.php.

Referenced by baseLoadBalancerParams().

◆ $loggerFields

LBFactory::$loggerFields
staticprivate
Initial value:
=
[ 'replLogger', 'connLogger', 'queryLogger', 'perfLogger' ]

Definition at line 76 of file LBFactory.php.

◆ $memCache

BagOStuff LBFactory::$memCache
protected

Definition at line 51 of file LBFactory.php.

◆ $perfLogger

LoggerInterface LBFactory::$perfLogger
protected

Definition at line 45 of file LBFactory.php.

◆ $profiler

object string LBFactory::$profiler
protected

Class name or object With profileIn/profileOut methods.

Definition at line 35 of file LBFactory.php.

Referenced by baseLoadBalancerParams().

◆ $queryLogger

LoggerInterface LBFactory::$queryLogger
protected

Definition at line 43 of file LBFactory.php.

Referenced by baseLoadBalancerParams().

◆ $readOnlyReason

string bool LBFactory::$readOnlyReason = false
protected

Reason all LBs are read-only or false if not.

Definition at line 67 of file LBFactory.php.

Referenced by baseLoadBalancerParams(), LBFactoryMulti\newLoadBalancer(), and LBFactoryMulti\newMainLB().

◆ $replicationWaitCallbacks

callable [] LBFactory::$replicationWaitCallbacks = []
protected

Definition at line 69 of file LBFactory.php.

◆ $replLogger

LoggerInterface LBFactory::$replLogger
protected

Definition at line 39 of file LBFactory.php.

Referenced by baseLoadBalancerParams().

◆ $requestInfo

array LBFactory::$requestInfo
protected

Web request information about the client.

Definition at line 60 of file LBFactory.php.

Referenced by setRequestInfo().

◆ $srvCache

BagOStuff LBFactory::$srvCache
protected

Definition at line 49 of file LBFactory.php.

Referenced by baseLoadBalancerParams().

◆ $ticket

mixed LBFactory::$ticket
protected

Definition at line 63 of file LBFactory.php.

Referenced by commitAndWaitForReplication(), and getEmptyTransactionTicket().

◆ $trxProfiler

TransactionProfiler LBFactory::$trxProfiler
protected

Definition at line 37 of file LBFactory.php.

Referenced by baseLoadBalancerParams().

◆ $trxRoundId

string bool LBFactory::$trxRoundId = false
protected

String if a requested DBO_TRX transaction round is active.

Definition at line 65 of file LBFactory.php.

Referenced by commitAndWaitForReplication().

◆ $wanCache

WANObjectCache LBFactory::$wanCache
protected

Definition at line 53 of file LBFactory.php.

Referenced by baseLoadBalancerParams().


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