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-rw-r--r--includes/db/LoadBalancer.php458
1 files changed, 268 insertions, 190 deletions
diff --git a/includes/db/LoadBalancer.php b/includes/db/LoadBalancer.php
index 857109db..e517a025 100644
--- a/includes/db/LoadBalancer.php
+++ b/includes/db/LoadBalancer.php
@@ -28,19 +28,43 @@
* @ingroup Database
*/
class LoadBalancer {
- private $mServers, $mConns, $mLoads, $mGroupLoads;
+ /** @var array Map of (server index => server config array) */
+ private $mServers;
+ /** @var array Map of (local/foreignUsed/foreignFree => server index => DatabaseBase array) */
+ private $mConns;
+ /** @var array Map of (server index => weight) */
+ private $mLoads;
+ /** @var array Map of (group => server index => weight) */
+ private $mGroupLoads;
+ /** @var bool Whether to disregard slave lag as a factor in slave selection */
+ private $mAllowLagged;
+ /** @var integer Seconds to spend waiting on slave lag to resolve */
+ private $mWaitTimeout;
+
+ /** @var array LBFactory information */
+ private $mParentInfo;
+ /** @var string The LoadMonitor subclass name */
+ private $mLoadMonitorClass;
+ /** @var LoadMonitor */
+ private $mLoadMonitor;
+
+ /** @var bool|DatabaseBase Database connection that caused a problem */
private $mErrorConnection;
- private $mReadIndex, $mAllowLagged;
- private $mWaitForPos, $mWaitTimeout;
- private $mLaggedSlaveMode, $mLastError = 'Unknown error';
- private $mParentInfo, $mLagTimes;
- private $mLoadMonitorClass, $mLoadMonitor;
+ /** @var integer The generic (not query grouped) slave index (of $mServers) */
+ private $mReadIndex;
+ /** @var bool|DBMasterPos False if not set */
+ private $mWaitForPos;
+ /** @var bool Whether the generic reader fell back to a lagged slave */
+ private $mLaggedSlaveMode;
+ /** @var string The last DB selection or connection error */
+ private $mLastError = 'Unknown error';
+ /** @var array Process cache of LoadMonitor::getLagTimes() */
+ private $mLagTimes;
/**
- * @param array $params with keys:
- * servers Required. Array of server info structures.
- * masterWaitTimeout Replication lag wait timeout
- * loadMonitor Name of a class used to fetch server lag and load.
+ * @param array $params Array with keys:
+ * servers Required. Array of server info structures.
+ * loadMonitor Name of a class used to fetch server lag and load.
* @throws MWException
*/
function __construct( $params ) {
@@ -48,12 +72,7 @@ class LoadBalancer {
throw new MWException( __CLASS__ . ': missing servers parameter' );
}
$this->mServers = $params['servers'];
-
- if ( isset( $params['waitTimeout'] ) ) {
- $this->mWaitTimeout = $params['waitTimeout'];
- } else {
- $this->mWaitTimeout = 10;
- }
+ $this->mWaitTimeout = 10;
$this->mReadIndex = -1;
$this->mWriteIndex = -1;
@@ -72,9 +91,9 @@ class LoadBalancer {
} else {
$master = reset( $params['servers'] );
if ( isset( $master['type'] ) && $master['type'] === 'mysql' ) {
- $this->mLoadMonitorClass = 'LoadMonitor_MySQL';
+ $this->mLoadMonitorClass = 'LoadMonitorMySQL';
} else {
- $this->mLoadMonitorClass = 'LoadMonitor_Null';
+ $this->mLoadMonitorClass = 'LoadMonitorNull';
}
}
@@ -101,13 +120,14 @@ class LoadBalancer {
$class = $this->mLoadMonitorClass;
$this->mLoadMonitor = new $class( $this );
}
+
return $this->mLoadMonitor;
}
/**
* Get or set arbitrary data used by the parent object, usually an LBFactory
- * @param $x
- * @return Mixed
+ * @param mixed $x
+ * @return mixed
*/
function parentInfo( $x = null ) {
return wfSetVar( $this->mParentInfo, $x );
@@ -119,8 +139,7 @@ class LoadBalancer {
*
* @deprecated since 1.21, use ArrayUtils::pickRandom()
*
- * @param $weights array
- *
+ * @param array $weights
* @return bool|int|string
*/
function pickRandom( $weights ) {
@@ -128,8 +147,8 @@ class LoadBalancer {
}
/**
- * @param $loads array
- * @param $wiki bool
+ * @param array $loads
+ * @param bool|string $wiki Wiki to get non-lagged for
* @return bool|int|string
*/
function getRandomNonLagged( $loads, $wiki = false ) {
@@ -138,10 +157,10 @@ class LoadBalancer {
foreach ( $lags as $i => $lag ) {
if ( $i != 0 ) {
if ( $lag === false ) {
- wfDebugLog( 'replication', "Server #$i is not replicating\n" );
+ wfDebugLog( 'replication', "Server #$i is not replicating" );
unset( $loads[$i] );
} elseif ( isset( $this->mServers[$i]['max lag'] ) && $lag > $this->mServers[$i]['max lag'] ) {
- wfDebugLog( 'replication', "Server #$i is excessively lagged ($lag seconds)\n" );
+ wfDebugLog( 'replication', "Server #$i is excessively lagged ($lag seconds)" );
unset( $loads[$i] );
}
}
@@ -176,13 +195,13 @@ class LoadBalancer {
* always return a consistent index during a given invocation
*
* Side effect: opens connections to databases
- * @param $group bool
- * @param $wiki bool
+ * @param bool|string $group
+ * @param bool|string $wiki
* @throws MWException
* @return bool|int|string
*/
function getReaderIndex( $group = false, $wiki = false ) {
- global $wgReadOnly, $wgDBClusterTimeout, $wgDBAvgStatusPoll, $wgDBtype;
+ global $wgReadOnly, $wgDBtype;
# @todo FIXME: For now, only go through all this for mysql databases
if ( $wgDBtype != 'mysql' ) {
@@ -192,17 +211,12 @@ class LoadBalancer {
if ( count( $this->mServers ) == 1 ) {
# Skip the load balancing if there's only one server
return 0;
- } elseif ( $group === false and $this->mReadIndex >= 0 ) {
+ } elseif ( $group === false && $this->mReadIndex >= 0 ) {
# Shortcut if generic reader exists already
return $this->mReadIndex;
}
- wfProfileIn( __METHOD__ );
-
- $totalElapsed = 0;
-
- # convert from seconds to microseconds
- $timeout = $wgDBClusterTimeout * 1e6;
+ $section = new ProfileSection( __METHOD__ );
# Find the relevant load array
if ( $group !== false ) {
@@ -211,15 +225,14 @@ class LoadBalancer {
} else {
# No loads for this group, return false and the caller can use some other group
wfDebug( __METHOD__ . ": no loads for group $group\n" );
- wfProfileOut( __METHOD__ );
+
return false;
}
} else {
$nonErrorLoads = $this->mLoads;
}
- if ( !$nonErrorLoads ) {
- wfProfileOut( __METHOD__ );
+ if ( !count( $nonErrorLoads ) ) {
throw new MWException( "Empty server array given to LoadBalancer" );
}
@@ -228,92 +241,60 @@ class LoadBalancer {
$laggedSlaveMode = false;
+ # No server found yet
+ $i = false;
# First try quickly looking through the available servers for a server that
# meets our criteria
- do {
- $totalThreadsConnected = 0;
- $overloadedServers = 0;
- $currentLoads = $nonErrorLoads;
- while ( count( $currentLoads ) ) {
- if ( $wgReadOnly || $this->mAllowLagged || $laggedSlaveMode ) {
+ $currentLoads = $nonErrorLoads;
+ while ( count( $currentLoads ) ) {
+ if ( $wgReadOnly || $this->mAllowLagged || $laggedSlaveMode ) {
+ $i = ArrayUtils::pickRandom( $currentLoads );
+ } else {
+ $i = $this->getRandomNonLagged( $currentLoads, $wiki );
+ if ( $i === false && count( $currentLoads ) != 0 ) {
+ # All slaves lagged. Switch to read-only mode
+ wfDebugLog( 'replication', "All slaves lagged. Switch to read-only mode" );
+ $wgReadOnly = 'The database has been automatically locked ' .
+ 'while the slave database servers catch up to the master';
$i = ArrayUtils::pickRandom( $currentLoads );
- } else {
- $i = $this->getRandomNonLagged( $currentLoads, $wiki );
- if ( $i === false && count( $currentLoads ) != 0 ) {
- # All slaves lagged. Switch to read-only mode
- wfDebugLog( 'replication', "All slaves lagged. Switch to read-only mode\n" );
- $wgReadOnly = 'The database has been automatically locked ' .
- 'while the slave database servers catch up to the master';
- $i = ArrayUtils::pickRandom( $currentLoads );
- $laggedSlaveMode = true;
- }
- }
-
- if ( $i === false ) {
- # pickRandom() returned false
- # This is permanent and means the configuration or the load monitor
- # wants us to return false.
- wfDebugLog( 'connect', __METHOD__ . ": pickRandom() returned false\n" );
- wfProfileOut( __METHOD__ );
- return false;
+ $laggedSlaveMode = true;
}
+ }
- wfDebugLog( 'connect', __METHOD__ . ": Using reader #$i: {$this->mServers[$i]['host']}...\n" );
- $conn = $this->openConnection( $i, $wiki );
-
- if ( !$conn ) {
- wfDebugLog( 'connect', __METHOD__ . ": Failed connecting to $i/$wiki\n" );
- unset( $nonErrorLoads[$i] );
- unset( $currentLoads[$i] );
- continue;
- }
-
- // Perform post-connection backoff
- $threshold = isset( $this->mServers[$i]['max threads'] )
- ? $this->mServers[$i]['max threads'] : false;
- $backoff = $this->getLoadMonitor()->postConnectionBackoff( $conn, $threshold );
-
- // Decrement reference counter, we are finished with this connection.
- // It will be incremented for the caller later.
- if ( $wiki !== false ) {
- $this->reuseConnection( $conn );
- }
+ if ( $i === false ) {
+ # pickRandom() returned false
+ # This is permanent and means the configuration or the load monitor
+ # wants us to return false.
+ wfDebugLog( 'connect', __METHOD__ . ": pickRandom() returned false" );
- if ( $backoff ) {
- # Post-connection overload, don't use this server for now
- $totalThreadsConnected += $backoff;
- $overloadedServers++;
- unset( $currentLoads[$i] );
- } else {
- # Return this server
- break 2;
- }
+ return false;
}
- # No server found yet
- $i = false;
+ wfDebugLog( 'connect', __METHOD__ .
+ ": Using reader #$i: {$this->mServers[$i]['host']}..." );
- # If all servers were down, quit now
- if ( !count( $nonErrorLoads ) ) {
- wfDebugLog( 'connect', "All servers down\n" );
- break;
+ $conn = $this->openConnection( $i, $wiki );
+ if ( !$conn ) {
+ wfDebugLog( 'connect', __METHOD__ . ": Failed connecting to $i/$wiki" );
+ unset( $nonErrorLoads[$i] );
+ unset( $currentLoads[$i] );
+ $i = false;
+ continue;
}
- # Some servers must have been overloaded
- if ( $overloadedServers == 0 ) {
- throw new MWException( __METHOD__ . ": unexpectedly found no overloaded servers" );
+ // Decrement reference counter, we are finished with this connection.
+ // It will be incremented for the caller later.
+ if ( $wiki !== false ) {
+ $this->reuseConnection( $conn );
}
- # Back off for a while
- # Scale the sleep time by the number of connected threads, to produce a
- # roughly constant global poll rate
- $avgThreads = $totalThreadsConnected / $overloadedServers;
- $totalElapsed += $this->sleep( $wgDBAvgStatusPoll * $avgThreads );
- } while ( $totalElapsed < $timeout );
-
- if ( $totalElapsed >= $timeout ) {
- wfDebugLog( 'connect', "All servers busy\n" );
- $this->mErrorConnection = false;
- $this->mLastError = 'All servers busy';
+
+ # Return this server
+ break;
+ }
+
+ # If all servers were down, quit now
+ if ( !count( $nonErrorLoads ) ) {
+ wfDebugLog( 'connect', "All servers down" );
}
if ( $i !== false ) {
@@ -324,17 +305,17 @@ class LoadBalancer {
$this->mServers[$i]['slave pos'] = $conn->getSlavePos();
}
}
- if ( $this->mReadIndex <= 0 && $this->mLoads[$i] > 0 && $i !== false ) {
+ if ( $this->mReadIndex <= 0 && $this->mLoads[$i] > 0 && $group !== false ) {
$this->mReadIndex = $i;
}
}
- wfProfileOut( __METHOD__ );
+
return $i;
}
/**
* Wait for a specified number of microseconds, and return the period waited
- * @param $t int
+ * @param int $t
* @return int
*/
function sleep( $t ) {
@@ -342,6 +323,7 @@ class LoadBalancer {
wfDebug( __METHOD__ . ": waiting $t us\n" );
usleep( $t );
wfProfileOut( __METHOD__ );
+
return $t;
}
@@ -349,7 +331,7 @@ class LoadBalancer {
* Set the master wait position
* If a DB_SLAVE connection has been opened already, waits
* Otherwise sets a variable telling it to wait if such a connection is opened
- * @param $pos DBMasterPos
+ * @param DBMasterPos $pos
*/
public function waitFor( $pos ) {
wfProfileIn( __METHOD__ );
@@ -367,22 +349,31 @@ class LoadBalancer {
/**
* Set the master wait position and wait for ALL slaves to catch up to it
- * @param $pos DBMasterPos
+ * @param DBMasterPos $pos
+ * @param int $timeout Max seconds to wait; default is mWaitTimeout
+ * @return bool Success (able to connect and no timeouts reached)
*/
- public function waitForAll( $pos ) {
+ public function waitForAll( $pos, $timeout = null ) {
wfProfileIn( __METHOD__ );
$this->mWaitForPos = $pos;
- for ( $i = 1; $i < count( $this->mServers ); $i++ ) {
- $this->doWait( $i, true );
+ $serverCount = count( $this->mServers );
+
+ $ok = true;
+ for ( $i = 1; $i < $serverCount; $i++ ) {
+ if ( $this->mLoads[$i] > 0 ) {
+ $ok = $this->doWait( $i, true, $timeout ) && $ok;
+ }
}
wfProfileOut( __METHOD__ );
+
+ return $ok;
}
/**
* Get any open connection to a given server index, local or foreign
* Returns false if there is no connection open
*
- * @param $i int
+ * @param int $i
* @return DatabaseBase|bool False on failure
*/
function getAnyOpenConnection( $i ) {
@@ -391,40 +382,47 @@ class LoadBalancer {
return reset( $conns[$i] );
}
}
+
return false;
}
/**
* Wait for a given slave to catch up to the master pos stored in $this
- * @param $index
- * @param $open bool
+ * @param int $index Server index
+ * @param bool $open Check the server even if a new connection has to be made
+ * @param int $timeout Max seconds to wait; default is mWaitTimeout
* @return bool
*/
- protected function doWait( $index, $open = false ) {
+ protected function doWait( $index, $open = false, $timeout = null ) {
# Find a connection to wait on
$conn = $this->getAnyOpenConnection( $index );
if ( !$conn ) {
if ( !$open ) {
wfDebug( __METHOD__ . ": no connection open\n" );
+
return false;
} else {
$conn = $this->openConnection( $index, '' );
if ( !$conn ) {
wfDebug( __METHOD__ . ": failed to open connection\n" );
+
return false;
}
}
}
wfDebug( __METHOD__ . ": Waiting for slave #$index to catch up...\n" );
- $result = $conn->masterPosWait( $this->mWaitForPos, $this->mWaitTimeout );
+ $timeout = $timeout ?: $this->mWaitTimeout;
+ $result = $conn->masterPosWait( $this->mWaitForPos, $timeout );
if ( $result == -1 || is_null( $result ) ) {
# Timed out waiting for slave, use master instead
wfDebug( __METHOD__ . ": Timed out waiting for slave #$index pos {$this->mWaitForPos}\n" );
+
return false;
} else {
wfDebug( __METHOD__ . ": Done\n" );
+
return true;
}
}
@@ -433,8 +431,8 @@ class LoadBalancer {
* Get a connection by index
* This is the main entry point for this class.
*
- * @param $i Integer: server index
- * @param array $groups query groups
+ * @param int $i Server index
+ * @param array $groups Query groups
* @param bool|string $wiki Wiki ID
*
* @throws MWException
@@ -443,12 +441,10 @@ class LoadBalancer {
public function &getConnection( $i, $groups = array(), $wiki = false ) {
wfProfileIn( __METHOD__ );
- if ( $i == DB_LAST ) {
+ if ( $i === null || $i === false ) {
wfProfileOut( __METHOD__ );
- throw new MWException( 'Attempt to call ' . __METHOD__ . ' with deprecated server index DB_LAST' );
- } elseif ( $i === null || $i === false ) {
- wfProfileOut( __METHOD__ );
- throw new MWException( 'Attempt to call ' . __METHOD__ . ' with invalid server index' );
+ throw new MWException( 'Attempt to call ' . __METHOD__ .
+ ' with invalid server index' );
}
if ( $wiki === wfWikiID() ) {
@@ -485,6 +481,7 @@ class LoadBalancer {
if ( $i === false ) {
$this->mLastError = 'No working slave server: ' . $this->mLastError;
wfProfileOut( __METHOD__ );
+
return $this->reportConnectionError();
}
}
@@ -493,10 +490,12 @@ class LoadBalancer {
$conn = $this->openConnection( $i, $wiki );
if ( !$conn ) {
wfProfileOut( __METHOD__ );
+
return $this->reportConnectionError();
}
wfProfileOut( __METHOD__ );
+
return $conn;
}
@@ -511,15 +510,9 @@ class LoadBalancer {
public function reuseConnection( $conn ) {
$serverIndex = $conn->getLBInfo( 'serverIndex' );
$refCount = $conn->getLBInfo( 'foreignPoolRefCount' );
- $dbName = $conn->getDBname();
- $prefix = $conn->tablePrefix();
- if ( strval( $prefix ) !== '' ) {
- $wiki = "$dbName-$prefix";
- } else {
- $wiki = $dbName;
- }
if ( $serverIndex === null || $refCount === null ) {
wfDebug( __METHOD__ . ": this connection was not opened as a foreign connection\n" );
+
/**
* This can happen in code like:
* foreach ( $dbs as $db ) {
@@ -530,10 +523,20 @@ class LoadBalancer {
* When a connection to the local DB is opened in this way, reuseConnection()
* should be ignored
*/
+
return;
}
+
+ $dbName = $conn->getDBname();
+ $prefix = $conn->tablePrefix();
+ if ( strval( $prefix ) !== '' ) {
+ $wiki = "$dbName-$prefix";
+ } else {
+ $wiki = $dbName;
+ }
if ( $this->mConns['foreignUsed'][$serverIndex][$wiki] !== $conn ) {
- throw new MWException( __METHOD__ . ": connection not found, has the connection been freed already?" );
+ throw new MWException( __METHOD__ . ": connection not found, has " .
+ "the connection been freed already?" );
}
$conn->setLBInfo( 'foreignPoolRefCount', --$refCount );
if ( $refCount <= 0 ) {
@@ -552,9 +555,9 @@ class LoadBalancer {
*
* @see LoadBalancer::getConnection() for parameter information
*
- * @param integer $db
+ * @param int $db
* @param mixed $groups
- * @param string $wiki
+ * @param bool|string $wiki
* @return DBConnRef
*/
public function getConnectionRef( $db, $groups = array(), $wiki = false ) {
@@ -568,9 +571,9 @@ class LoadBalancer {
*
* @see LoadBalancer::getConnection() for parameter information
*
- * @param integer $db
+ * @param int $db
* @param mixed $groups
- * @param string $wiki
+ * @param bool|string $wiki
* @return DBConnRef
*/
public function getLazyConnectionRef( $db, $groups = array(), $wiki = false ) {
@@ -585,8 +588,8 @@ class LoadBalancer {
* On error, returns false, and the connection which caused the
* error will be available via $this->mErrorConnection.
*
- * @param $i Integer server index
- * @param string $wiki wiki ID to open
+ * @param int $i Server index
+ * @param bool|string $wiki Wiki ID to open
* @return DatabaseBase
*
* @access private
@@ -596,6 +599,7 @@ class LoadBalancer {
if ( $wiki !== false ) {
$conn = $this->openForeignConnection( $i, $wiki );
wfProfileOut( __METHOD__ );
+
return $conn;
}
if ( isset( $this->mConns['local'][$i][0] ) ) {
@@ -614,6 +618,7 @@ class LoadBalancer {
}
}
wfProfileOut( __METHOD__ );
+
return $conn;
}
@@ -631,8 +636,8 @@ class LoadBalancer {
* On error, returns false, and the connection which caused the
* error will be available via $this->mErrorConnection.
*
- * @param $i Integer: server index
- * @param string $wiki wiki ID to open
+ * @param int $i Server index
+ * @param string $wiki Wiki ID to open
* @return DatabaseBase
*/
function openForeignConnection( $i, $wiki ) {
@@ -688,13 +693,14 @@ class LoadBalancer {
$conn->setLBInfo( 'foreignPoolRefCount', $refCount + 1 );
}
wfProfileOut( __METHOD__ );
+
return $conn;
}
/**
* Test if the specified index represents an open connection
*
- * @param $index Integer: server index
+ * @param int $index Server index
* @access private
* @return bool
*/
@@ -702,6 +708,7 @@ class LoadBalancer {
if ( !is_integer( $index ) ) {
return false;
}
+
return (bool)$this->getAnyOpenConnection( $index );
}
@@ -710,8 +717,8 @@ class LoadBalancer {
* Returns a Database object whether or not the connection was successful.
* @access private
*
- * @param $server
- * @param $dbNameOverride bool
+ * @param array $server
+ * @param bool $dbNameOverride
* @throws MWException
* @return DatabaseBase
*/
@@ -741,6 +748,7 @@ class LoadBalancer {
if ( isset( $server['fakeMaster'] ) ) {
$db->setFakeMaster( true );
}
+
return $db;
}
@@ -753,15 +761,16 @@ class LoadBalancer {
if ( !is_object( $conn ) ) {
// No last connection, probably due to all servers being too busy
- wfLogDBError( "LB failure with no last connection. Connection error: {$this->mLastError}\n" );
+ wfLogDBError( "LB failure with no last connection. Connection error: {$this->mLastError}" );
// If all servers were busy, mLastError will contain something sensible
throw new DBConnectionError( null, $this->mLastError );
} else {
$server = $conn->getProperty( 'mServer' );
- wfLogDBError( "Connection error: {$this->mLastError} ({$server})\n" );
+ wfLogDBError( "Connection error: {$this->mLastError} ({$server})" );
$conn->reportConnectionError( "{$this->mLastError} ({$server})" ); // throws DBConnectionError
}
+
return false; /* not reached */
}
@@ -775,7 +784,7 @@ class LoadBalancer {
/**
* Returns true if the specified index is a valid server index
*
- * @param $i
+ * @param string $i
* @return bool
*/
function haveIndex( $i ) {
@@ -785,7 +794,7 @@ class LoadBalancer {
/**
* Returns true if the specified index is valid and has non-zero load
*
- * @param $i
+ * @param string $i
* @return bool
*/
function isNonZeroLoad( $i ) {
@@ -804,7 +813,7 @@ class LoadBalancer {
/**
* Get the host name or IP address of the server with the specified index
* Prefer a readable name if available.
- * @param $i
+ * @param string $i
* @return string
*/
function getServerName( $i ) {
@@ -819,8 +828,8 @@ class LoadBalancer {
/**
* Return the server info structure for a given index, or false if the index is invalid.
- * @param $i
- * @return bool
+ * @param int $i
+ * @return array|bool
*/
function getServerInfo( $i ) {
if ( isset( $this->mServers[$i] ) ) {
@@ -831,9 +840,10 @@ class LoadBalancer {
}
/**
- * Sets the server info structure for the given index. Entry at index $i is created if it doesn't exist
- * @param $i
- * @param $serverInfo
+ * Sets the server info structure for the given index. Entry at index $i
+ * is created if it doesn't exist
+ * @param int $i
+ * @param array $serverInfo
*/
function setServerInfo( $i, $serverInfo ) {
$this->mServers[$i] = $serverInfo;
@@ -848,17 +858,21 @@ class LoadBalancer {
# master (however unlikely that may be), then we can fetch the position from the slave.
$masterConn = $this->getAnyOpenConnection( 0 );
if ( !$masterConn ) {
- for ( $i = 1; $i < count( $this->mServers ); $i++ ) {
+ $serverCount = count( $this->mServers );
+ for ( $i = 1; $i < $serverCount; $i++ ) {
$conn = $this->getAnyOpenConnection( $i );
if ( $conn ) {
wfDebug( "Master pos fetched from slave\n" );
+
return $conn->getSlavePos();
}
}
} else {
wfDebug( "Master pos fetched from master\n" );
+
return $masterConn->getMasterPos();
}
+
return false;
}
@@ -868,6 +882,7 @@ class LoadBalancer {
function closeAll() {
foreach ( $this->mConns as $conns2 ) {
foreach ( $conns2 as $conns3 ) {
+ /** @var DatabaseBase $conn */
foreach ( $conns3 as $conn ) {
$conn->close();
}
@@ -881,21 +896,10 @@ class LoadBalancer {
}
/**
- * Deprecated function, typo in function name
- *
- * @deprecated in 1.18
- * @param $conn
- */
- function closeConnecton( $conn ) {
- wfDeprecated( __METHOD__, '1.18' );
- $this->closeConnection( $conn );
- }
-
- /**
* Close a connection
* Using this function makes sure the LoadBalancer knows the connection is closed.
* If you use $conn->close() directly, the load balancer won't update its state.
- * @param $conn DatabaseBase
+ * @param DatabaseBase $conn
*/
function closeConnection( $conn ) {
$done = false;
@@ -922,6 +926,7 @@ class LoadBalancer {
function commitAll() {
foreach ( $this->mConns as $conns2 ) {
foreach ( $conns2 as $conns3 ) {
+ /** @var DatabaseBase[] $conns3 */
foreach ( $conns3 as $conn ) {
if ( $conn->trxLevel() ) {
$conn->commit( __METHOD__, 'flush' );
@@ -941,6 +946,7 @@ class LoadBalancer {
if ( empty( $conns2[$masterIndex] ) ) {
continue;
}
+ /** @var DatabaseBase $conn */
foreach ( $conns2[$masterIndex] as $conn ) {
if ( $conn->trxLevel() && $conn->writesOrCallbacksPending() ) {
$conn->commit( __METHOD__, 'flush' );
@@ -950,8 +956,59 @@ class LoadBalancer {
}
/**
- * @param $value null
- * @return Mixed
+ * Issue ROLLBACK only on master, only if queries were done on connection
+ * @since 1.23
+ */
+ function rollbackMasterChanges() {
+ // Always 0, but who knows.. :)
+ $masterIndex = $this->getWriterIndex();
+ foreach ( $this->mConns as $conns2 ) {
+ if ( empty( $conns2[$masterIndex] ) ) {
+ continue;
+ }
+ /** @var DatabaseBase $conn */
+ foreach ( $conns2[$masterIndex] as $conn ) {
+ if ( $conn->trxLevel() && $conn->writesOrCallbacksPending() ) {
+ $conn->rollback( __METHOD__, 'flush' );
+ }
+ }
+ }
+ }
+
+ /**
+ * @return bool Whether a master connection is already open
+ * @since 1.24
+ */
+ function hasMasterConnection() {
+ return $this->isOpen( $this->getWriterIndex() );
+ }
+
+ /**
+ * Determine if there are any pending changes that need to be rolled back
+ * or committed.
+ * @since 1.23
+ * @return bool
+ */
+ function hasMasterChanges() {
+ // Always 0, but who knows.. :)
+ $masterIndex = $this->getWriterIndex();
+ foreach ( $this->mConns as $conns2 ) {
+ if ( empty( $conns2[$masterIndex] ) ) {
+ continue;
+ }
+ /** @var DatabaseBase $conn */
+ foreach ( $conns2[$masterIndex] as $conn ) {
+ if ( $conn->trxLevel() && $conn->writesOrCallbacksPending() ) {
+ return true;
+ }
+ }
+ }
+ return false;
+ }
+
+ /**
+ * @param mixed $value
+ * @return mixed
*/
function waitTimeout( $value = null ) {
return wfSetVar( $this->mWaitTimeout, $value );
@@ -966,7 +1023,7 @@ class LoadBalancer {
/**
* Disables/enables lag checks
- * @param $mode null
+ * @param null|bool $mode
* @return bool
*/
function allowLagged( $mode = null ) {
@@ -974,6 +1031,7 @@ class LoadBalancer {
return $this->mAllowLagged;
}
$this->mAllowLagged = $mode;
+
return $this->mAllowLagged;
}
@@ -984,6 +1042,7 @@ class LoadBalancer {
$success = true;
foreach ( $this->mConns as $conns2 ) {
foreach ( $conns2 as $conns3 ) {
+ /** @var DatabaseBase[] $conns3 */
foreach ( $conns3 as $conn ) {
if ( !$conn->ping() ) {
$success = false;
@@ -991,12 +1050,13 @@ class LoadBalancer {
}
}
}
+
return $success;
}
/**
* Call a function with each open connection object
- * @param $callback
+ * @param callable $callback
* @param array $params
*/
function forEachOpenConnection( $callback, $params = array() ) {
@@ -1016,16 +1076,29 @@ class LoadBalancer {
* May attempt to open connections to slaves on the default DB. If there is
* no lag, the maximum lag will be reported as -1.
*
- * @param string $wiki Wiki ID, or false for the default database
- *
+ * @param bool|string $wiki Wiki ID, or false for the default database
* @return array ( host, max lag, index of max lagged host )
*/
function getMaxLag( $wiki = false ) {
$maxLag = -1;
$host = '';
$maxIndex = 0;
- if ( $this->getServerCount() > 1 ) { // no replication = no lag
+
+ if ( $this->getServerCount() <= 1 ) { // no replication = no lag
+ return array( $host, $maxLag, $maxIndex );
+ }
+
+ // Try to get the max lag info from the server cache
+ $key = 'loadbalancer:maxlag:cluster:' . $this->mServers[0]['host'];
+ $cache = ObjectCache::newAccelerator( array(), 'hash' );
+ $maxLagInfo = $cache->get( $key ); // (host, lag, index)
+
+ // Fallback to connecting to each slave and getting the lag
+ if ( !$maxLagInfo ) {
foreach ( $this->mServers as $i => $conn ) {
+ if ( $i == $this->getWriterIndex() ) {
+ continue; // nothing to check
+ }
$conn = false;
if ( $wiki === false ) {
$conn = $this->getAnyOpenConnection( $i );
@@ -1043,16 +1116,18 @@ class LoadBalancer {
$maxIndex = $i;
}
}
+ $maxLagInfo = array( $host, $maxLag, $maxIndex );
+ $cache->set( $key, $maxLagInfo, 5 );
}
- return array( $host, $maxLag, $maxIndex );
+
+ return $maxLagInfo;
}
/**
* Get lag time for each server
* Results are cached for a short time in memcached, and indefinitely in the process cache
*
- * @param $wiki
- *
+ * @param string|bool $wiki
* @return array
*/
function getLagTimes( $wiki = false ) {
@@ -1068,6 +1143,7 @@ class LoadBalancer {
$this->mLagTimes = $this->getLoadMonitor()->getLagTimes(
array_keys( $this->mServers ), $wiki );
}
+
return $this->mLagTimes;
}
@@ -1082,8 +1158,7 @@ class LoadBalancer {
* function instead of Database::getLag() avoids a fatal error in this
* case on many installations.
*
- * @param $conn DatabaseBase
- *
+ * @param DatabaseBase $conn
* @return int
*/
function safeGetLag( $conn ) {
@@ -1112,14 +1187,16 @@ class LoadBalancer {
class DBConnRef implements IDatabase {
/** @var LoadBalancer */
protected $lb;
+
/** @var DatabaseBase|null */
protected $conn;
- /** @var Array|null */
+
+ /** @var array|null */
protected $params;
/**
- * @param $lb LoadBalancer
- * @param $conn DatabaseBase|array Connection or (server index, group, wiki ID) array
+ * @param LoadBalancer $lb
+ * @param DatabaseBase|array $conn Connection or (server index, group, wiki ID) array
*/
public function __construct( LoadBalancer $lb, $conn ) {
$this->lb = $lb;
@@ -1135,6 +1212,7 @@ class DBConnRef implements IDatabase {
list( $db, $groups, $wiki ) = $this->params;
$this->conn = $this->lb->getConnection( $db, $groups, $wiki );
}
+
return call_user_func_array( array( $this->conn, $name ), $arguments );
}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-19 05:53:55 +0000