Version of LockManager based on using named/row DB locks. More...

Inheritance diagram for DBLockManager:

Collaboration diagram for DBLockManager:

Public Member Functions
	__construct (array $config)
	Construct a new instance from configuration. More...

	__destruct ()
	Make sure remaining locks get cleared for sanity. More...

Public Member Functions inherited from LockManager
	__construct (array $config)
	Construct a new instance from configuration. More...

	lock (array $paths, $type=self::LOCK_EX, $timeout=0)
	Lock the resources at the given abstract paths. More...

	lockByType (array $pathsByType, $timeout=0)
	Lock the resources at the given abstract paths. More...

	unlock (array $paths, $type=self::LOCK_EX)
	Unlock the resources at the given abstract paths. More...

	unlockByType (array $pathsByType)
	Unlock the resources at the given abstract paths. More...

Protected Member Functions
	cacheCheckFailures ($lockDb)
	Checks if the DB has not recently had connection/query errors. More...

	cacheRecordFailure ($lockDb)
	Log a lock request failure to the cache. More...

	doGetLocksOnServer ($lockSrv, array $paths, $type)

	freeLocksOnServer ($lockSrv, array $pathsByType)

	getConnection ($lockDb)
	Get (or reuse) a connection to a lock DB. More...

	getLocksOnServer ($lockSrv, array $pathsByType)

	getMissKey ($lockDb)
	Get a cache key for recent query misses for a DB. More...

	initConnection ($lockDb, IDatabase $db)
	Do additional initialization for new lock DB connection. More...

	isServerUp ($lockSrv)

Protected Member Functions inherited from QuorumLockManager
	doLock (array $paths, $type)

	doLockByType (array $pathsByType)

	doLockingRequestBucket ($bucket, array $pathsByType)
	Attempt to acquire locks with the peers for a bucket. More...

	doUnlock (array $paths, $type)

	doUnlockByType (array $pathsByType)

	doUnlockingRequestBucket ($bucket, array $pathsByType)
	Attempt to release locks with the peers for a bucket. More...

	freeLocksOnServer ($lockSrv, array $pathsByType)
	Get a connection to a lock server and release locks on $paths. More...

	getBucketFromPath ($path)
	Get the bucket for resource path. More...

	getLocksOnServer ($lockSrv, array $pathsByType)
	Get a connection to a lock server and acquire locks. More...

	isServerUp ($lockSrv)
	Check if a lock server is up. More...

	releaseAllLocks ()
	Release all locks that this session is holding. More...

Protected Member Functions inherited from LockManager
	doLock (array $paths, $type)
	Lock resources with the given keys and lock type. More...

	doLockByType (array $pathsByType)

	doUnlock (array $paths, $type)
	Unlock resources with the given keys and lock type. More...

	doUnlockByType (array $pathsByType)

	normalizePathsByType (array $pathsByType)
	Normalize the $paths array by converting LOCK_UW locks into the appropriate type and removing any duplicated paths for each lock type. More...

	sha1Base16Absolute ($path)
	Get the base 16 SHA-1 of a string, padded to 31 digits. More...

	sha1Base36Absolute ($path)
	Get the base 36 SHA-1 of a string, padded to 31 digits. More...

Protected Attributes
IDatabase[]	$conns = []
	Map Database connections (DB name => Database) More...

array[]	$dbServers
	Map of DB names to server config. More...

	$lockExpiry

	$safeDelay

	$session = 0

BagOStuff	$statusCache

Protected Attributes inherited from QuorumLockManager
array	$degradedBuckets = []
	Map of degraded buckets. More...

array	$srvsByBucket = []
	Map of bucket indexes to peer server lists. More...

Protected Attributes inherited from LockManager
	$domain

array	$locksHeld = []
	Map of (resource path => lock type => count) More...

	$lockTTL

array	$lockTypeMap
	Mapping of lock types to the type actually used. More...

Additional Inherited Members
Public Attributes inherited from LockManager
const	LOCK_EX = 3

const	LOCK_SH = 1
	Lock types; stronger locks have higher values. More...

const	LOCK_UW = 2

Detailed Description

Version of LockManager based on using named/row DB locks.

This is meant for multi-wiki systems that may share files.

All lock requests for a resource, identified by a hash string, will map to one bucket. Each bucket maps to one or several peer DBs, each on their own server, all having the filelocks.sql tables (with row-level locking). A majority of peer DBs must agree for a lock to be acquired.

Caching is used to avoid hitting servers that are down.

Since: 1.19

Definition at line 39 of file DBLockManager.php.

Constructor & Destructor Documentation

DBLockManager::__construct ( array $config )

Construct a new instance from configuration.

Parameters

array

$config

Parameters include:

dbServers : Associative array of DB names to server configuration. Configuration is an associative array that includes:
- host : DB server name
- dbname : DB name
- type : DB type (mysql,postgres,...)
- user : DB user
- password : DB user password
- tablePrefix : DB table prefix
- flags : DB flags (see DatabaseBase)
dbsByBucket : Array of 1-16 consecutive integer keys, starting from 0, each having an odd-numbered list of DB names (peers) as values. Any DB named 'localDBMaster' will automatically use the DB master settings for this wiki (without the need for a dbServers entry). Only use 'localDBMaster' if the domain is a valid wiki ID.
lockExpiry : Lock timeout (seconds) for dropped connections. [optional] This tells the DB server how long to wait before assuming connection failure and releasing all the locks for a session.