/** How long before it is worth doing a dummy query to test the connection */
const PING_TTL = 1.0;
+ const PING_QUERY = 'SELECT 1 AS ping';
+
+ const TINY_WRITE_SEC = .010;
+ const SLOW_WRITE_SEC = .500;
+ const SMALL_WRITE_ROWS = 100;
/** @var string SQL query */
protected $mLastQuery = '';
protected $mPassword;
/** @var string */
protected $mDBname;
+ /** @var bool */
+ protected $cliMode;
/** @var BagOStuff APC cache */
protected $srvCache;
protected $mTrxPreCommitCallbacks = [];
/** @var array[] List of (callable, method name) */
protected $mTrxEndCallbacks = [];
- /** @var bool Whether to suppress triggering of post-commit callbacks */
- protected $suppressPostCommitCallbacks = false;
+ /** @var array[] Map of (name => (callable, method name)) */
+ protected $mTrxRecurringCallbacks = [];
+ /** @var bool Whether to suppress triggering of transaction end callbacks */
+ protected $mTrxEndCallbacksSuppressed = false;
/** @var string */
protected $mTablePrefix;
* @var int
*/
protected $mTrxLevel = 0;
-
/**
* Either a short hexidecimal string if a transaction is active or ""
*
* @see DatabaseBase::mTrxLevel
*/
protected $mTrxShortId = '';
-
/**
* The UNIX time that the transaction started. Callers can assume that if
* snapshot isolation is used, then the data is *at least* up to date to that
* @see DatabaseBase::mTrxLevel
*/
private $mTrxTimestamp = null;
-
/** @var float Lag estimate at the time of BEGIN */
- private $mTrxSlaveLag = null;
-
+ private $mTrxReplicaLag = null;
/**
* Remembers the function name given for starting the most recent transaction via begin().
* Used to provide additional context for error reporting.
* @see DatabaseBase::mTrxLevel
*/
private $mTrxFname = null;
-
/**
* Record if possible write queries were done in the last transaction started
*
* @see DatabaseBase::mTrxLevel
*/
private $mTrxDoneWrites = false;
-
/**
* Record if the current transaction was started implicitly due to DBO_TRX being set.
*
* @see DatabaseBase::mTrxLevel
*/
private $mTrxAutomatic = false;
-
/**
* Array of levels of atomicity within transactions
*
* @var array
*/
private $mTrxAtomicLevels = [];
-
/**
* Record if the current transaction was started implicitly by DatabaseBase::startAtomic
*
* @var bool
*/
private $mTrxAutomaticAtomic = false;
-
/**
* Track the write query callers of the current transaction
*
* @var string[]
*/
private $mTrxWriteCallers = [];
-
/**
- * Track the seconds spent in write queries for the current transaction
- *
- * @var float
+ * @var float Seconds spent in write queries for the current transaction
*/
private $mTrxWriteDuration = 0.0;
+ /**
+ * @var integer Number of write queries for the current transaction
+ */
+ private $mTrxWriteQueryCount = 0;
+ /**
+ * @var float Like mTrxWriteQueryCount but excludes lock-bound, easy to replicate, queries
+ */
+ private $mTrxWriteAdjDuration = 0.0;
+ /**
+ * @var integer Number of write queries counted in mTrxWriteAdjDuration
+ */
+ private $mTrxWriteAdjQueryCount = 0;
+ /**
+ * @var float RTT time estimate
+ */
+ private $mRTTEstimate = 0.0;
/** @var array Map of (name => 1) for locks obtained via lock() */
private $mNamedLocksHeld = [];
);
}
- public function pendingWriteQueryDuration() {
- return $this->mTrxLevel ? $this->mTrxWriteDuration : false;
+ public function pendingWriteQueryDuration( $type = self::ESTIMATE_TOTAL ) {
+ if ( !$this->mTrxLevel ) {
+ return false;
+ } elseif ( !$this->mTrxDoneWrites ) {
+ return 0.0;
+ }
+
+ switch ( $type ) {
+ case self::ESTIMATE_DB_APPLY:
+ $this->ping( $rtt );
+ $rttAdjTotal = $this->mTrxWriteAdjQueryCount * $rtt;
+ $applyTime = max( $this->mTrxWriteAdjDuration - $rttAdjTotal, 0 );
+ // For omitted queries, make them count as something at least
+ $omitted = $this->mTrxWriteQueryCount - $this->mTrxWriteAdjQueryCount;
+ $applyTime += self::TINY_WRITE_SEC * $omitted;
+
+ return $applyTime;
+ default: // everything
+ return $this->mTrxWriteDuration;
+ }
}
public function pendingWriteCallers() {
* @param array $params Parameters passed from DatabaseBase::factory()
*/
function __construct( array $params ) {
- global $wgDBprefix, $wgDBmwschema, $wgCommandLineMode;
+ global $wgDBprefix, $wgDBmwschema;
$this->srvCache = ObjectCache::getLocalServerInstance( 'hash' );
$schema = $params['schema'];
$foreign = $params['foreign'];
+ $this->cliMode = isset( $params['cliMode'] )
+ ? $params['cliMode']
+ : ( PHP_SAPI === 'cli' );
+
$this->mFlags = $flags;
if ( $this->mFlags & DBO_DEFAULT ) {
- if ( $wgCommandLineMode ) {
+ if ( $this->cliMode ) {
$this->mFlags &= ~DBO_TRX;
} else {
$this->mFlags |= DBO_TRX;
* @return DatabaseBase|null DatabaseBase subclass or null
*/
final public static function factory( $dbType, $p = [] ) {
+ global $wgCommandLineMode;
+
$canonicalDBTypes = [
'mysql' => [ 'mysqli', 'mysql' ],
'postgres' => [],
$p['schema'] = isset( $defaultSchemas[$dbType] ) ? $defaultSchemas[$dbType] : null;
}
$p['foreign'] = isset( $p['foreign'] ) ? $p['foreign'] : false;
+ $p['cliMode'] = $wgCommandLineMode;
return new $class( $p );
} else {
* @return bool
*/
protected function isWriteQuery( $sql ) {
- return !preg_match( '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
+ return !preg_match(
+ '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
+ }
+
+ /**
+ * @param $sql
+ * @return string|null
+ */
+ protected function getQueryVerb( $sql ) {
+ return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ? strtoupper( $m[1] ) : null;
}
/**
* @return bool
*/
protected function isTransactableQuery( $sql ) {
- $verb = substr( $sql, 0, strcspn( $sql, " \t\r\n" ) );
- return !in_array( $verb, [ 'BEGIN', 'COMMIT', 'ROLLBACK', 'SHOW', 'SET' ] );
+ $verb = $this->getQueryVerb( $sql );
+ return !in_array( $verb, [ 'BEGIN', 'COMMIT', 'ROLLBACK', 'SHOW', 'SET' ], true );
}
public function query( $sql, $fname = __METHOD__, $tempIgnore = false ) {
$this->profiler->profileIn( $queryProf );
$ret = $this->doQuery( $commentedSql );
$this->profiler->profileOut( $queryProf );
- $queryRuntime = microtime( true ) - $startTime;
+ $queryRuntime = max( microtime( true ) - $startTime, 0.0 );
unset( $queryProfSection ); // profile out (if set)
if ( $ret !== false ) {
$this->lastPing = $startTime;
if ( $isWrite && $this->mTrxLevel ) {
- $this->mTrxWriteDuration += $queryRuntime;
+ $this->updateTrxWriteQueryTime( $sql, $queryRuntime );
$this->mTrxWriteCallers[] = $fname;
}
}
+ if ( $sql === self::PING_QUERY ) {
+ $this->mRTTEstimate = $queryRuntime;
+ }
+
$this->getTransactionProfiler()->recordQueryCompletion(
$queryProf, $startTime, $isWrite, $this->affectedRows()
);
return $ret;
}
+ /**
+ * Update the estimated run-time of a query, not counting large row lock times
+ *
+ * LoadBalancer can be set to rollback transactions that will create huge replication
+ * lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
+ * queries, like inserting a row can take a long time due to row locking. This method
+ * uses some simple heuristics to discount those cases.
+ *
+ * @param string $sql A SQL write query
+ * @param float $runtime Total runtime, including RTT
+ */
+ private function updateTrxWriteQueryTime( $sql, $runtime ) {
+ // Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
+ $indicativeOfReplicaRuntime = true;
+ if ( $runtime > self::SLOW_WRITE_SEC ) {
+ $verb = $this->getQueryVerb( $sql );
+ // insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
+ if ( $verb === 'INSERT' ) {
+ $indicativeOfReplicaRuntime = $this->affectedRows() > self::SMALL_WRITE_ROWS;
+ } elseif ( $verb === 'REPLACE' ) {
+ $indicativeOfReplicaRuntime = $this->affectedRows() > self::SMALL_WRITE_ROWS / 2;
+ }
+ }
+
+ $this->mTrxWriteDuration += $runtime;
+ $this->mTrxWriteQueryCount += 1;
+ if ( $indicativeOfReplicaRuntime ) {
+ $this->mTrxWriteAdjDuration += $runtime;
+ $this->mTrxWriteAdjQueryCount += 1;
+ }
+ }
+
private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
# Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
# Dropped connections also mean that named locks are automatically released.
try {
// Handle callbacks in mTrxEndCallbacks
$this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
+ $this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
return null;
} catch ( Exception $e ) {
// Already logged; move on...
} else {
$useIndex = '';
}
+ if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
+ $ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
+ } else {
+ $ignoreIndex = '';
+ }
- return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail ];
+ return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
}
/**
$useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
? $options['USE INDEX']
: [];
+ $ignoreIndexes = ( isset( $options['IGNORE INDEX'] ) && is_array( $options['IGNORE INDEX'] ) )
+ ? $options['IGNORE INDEX']
+ : [];
if ( is_array( $table ) ) {
$from = ' FROM ' .
- $this->tableNamesWithUseIndexOrJOIN( $table, $useIndexes, $join_conds );
+ $this->tableNamesWithIndexClauseOrJOIN( $table, $useIndexes, $ignoreIndexes, $join_conds );
} elseif ( $table != '' ) {
if ( $table[0] == ' ' ) {
$from = ' FROM ' . $table;
} else {
$from = ' FROM ' .
- $this->tableNamesWithUseIndexOrJOIN( [ $table ], $useIndexes, [] );
+ $this->tableNamesWithIndexClauseOrJOIN( [ $table ], $useIndexes, $ignoreIndexes, [] );
}
} else {
$from = '';
}
- list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) =
+ list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
$this->makeSelectOptions( $options );
if ( !empty( $conds ) ) {
if ( is_array( $conds ) ) {
$conds = $this->makeList( $conds, LIST_AND );
}
- $sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
+ $sql = "SELECT $startOpts $vars $from $useIndex $ignoreIndex WHERE $conds $preLimitTail";
} else {
- $sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
+ $sql = "SELECT $startOpts $vars $from $useIndex $ignoreIndex $preLimitTail";
}
if ( isset( $options['LIMIT'] ) ) {
return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
}
+ /**
+ * @param string $field Field or column to cast
+ * @return string
+ * @since 1.28
+ */
+ public function buildStringCast( $field ) {
+ return $field;
+ }
+
public function selectDB( $db ) {
# Stub. Shouldn't cause serious problems if it's not overridden, but
# if your database engine supports a concept similar to MySQL's
/**
* Get the aliased table name clause for a FROM clause
- * which might have a JOIN and/or USE INDEX clause
+ * which might have a JOIN and/or USE INDEX or IGNORE INDEX clause
*
* @param array $tables ( [alias] => table )
* @param array $use_index Same as for select()
+ * @param array $ignore_index Same as for select()
* @param array $join_conds Same as for select()
* @return string
*/
- protected function tableNamesWithUseIndexOrJOIN(
- $tables, $use_index = [], $join_conds = []
+ protected function tableNamesWithIndexClauseOrJOIN(
+ $tables, $use_index = [], $ignore_index = [], $join_conds = []
) {
$ret = [];
$retJOIN = [];
$use_index = (array)$use_index;
+ $ignore_index = (array)$ignore_index;
$join_conds = (array)$join_conds;
foreach ( $tables as $alias => $table ) {
$tableClause .= ' ' . $use;
}
}
+ if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
+ $ignore = $this->ignoreIndexClause( implode( ',', (array)$ignore_index[$alias] ) );
+ if ( $ignore != '' ) {
+ $tableClause .= ' ' . $ignore;
+ }
+ }
$on = $this->makeList( (array)$conds, LIST_AND );
if ( $on != '' ) {
$tableClause .= ' ON (' . $on . ')';
implode( ',', (array)$use_index[$alias] )
);
+ $ret[] = $tableClause;
+ } elseif ( isset( $ignore_index[$alias] ) ) {
+ // Is there an INDEX clause for this table?
+ $tableClause = $this->tableNameWithAlias( $table, $alias );
+ $tableClause .= ' ' . $this->ignoreIndexClause(
+ implode( ',', (array)$ignore_index[$alias] )
+ );
+
$ret[] = $tableClause;
} else {
$tableClause = $this->tableNameWithAlias( $table, $alias );
return '';
}
+ /**
+ * IGNORE INDEX clause. Unlikely to be useful for anything but MySQL. This
+ * is only needed because a) MySQL must be as efficient as possible due to
+ * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
+ * which index to pick. Anyway, other databases might have different
+ * indexes on a given table. So don't bother overriding this unless you're
+ * MySQL.
+ * @param string $index
+ * @return string
+ */
+ public function ignoreIndexClause( $index ) {
+ return '';
+ }
+
public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
$quotedTable = $this->tableName( $table );
$ok = $this->insert( $table, $rows, $fname, [ 'IGNORE' ] ) && $ok;
} catch ( Exception $e ) {
if ( $useTrx ) {
- $this->rollback( $fname );
+ $this->rollback( $fname, self::FLUSHING_INTERNAL );
}
throw $e;
}
if ( $useTrx ) {
- $this->commit( $fname, self::TRANSACTION_INTERNAL );
+ $this->commit( $fname, self::FLUSHING_INTERNAL );
}
return $ok;
return $this->query( $sql, $fname );
}
- public function insertSelect( $destTable, $srcTable, $varMap, $conds,
+ public function insertSelect(
+ $destTable, $srcTable, $varMap, $conds,
+ $fname = __METHOD__, $insertOptions = [], $selectOptions = []
+ ) {
+ if ( $this->cliMode ) {
+ // For massive migrations with downtime, we don't want to select everything
+ // into memory and OOM, so do all this native on the server side if possible.
+ return $this->nativeInsertSelect(
+ $destTable,
+ $srcTable,
+ $varMap,
+ $conds,
+ $fname,
+ $insertOptions,
+ $selectOptions
+ );
+ }
+
+ // For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
+ // on only the master (without needing row-based-replication). It also makes it easy to
+ // know how big the INSERT is going to be.
+ $fields = [];
+ foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
+ $fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
+ }
+ $selectOptions[] = 'FOR UPDATE';
+ $res = $this->select( $srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions );
+ if ( !$res ) {
+ return false;
+ }
+
+ $rows = [];
+ foreach ( $res as $row ) {
+ $rows[] = (array)$row;
+ }
+
+ return $this->insert( $destTable, $rows, $fname, $insertOptions );
+ }
+
+ public function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
$fname = __METHOD__,
$insertOptions = [], $selectOptions = []
) {
$selectOptions = [ $selectOptions ];
}
- list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
+ list( $startOpts, $useIndex, $tailOpts, $ignoreIndex ) = $this->makeSelectOptions(
+ $selectOptions );
if ( is_array( $srcTable ) ) {
$srcTable = implode( ',', array_map( [ &$this, 'tableName' ], $srcTable ) );
$sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
" SELECT $startOpts " . implode( ',', $varMap ) .
- " FROM $srcTable $useIndex ";
+ " FROM $srcTable $useIndex $ignoreIndex ";
if ( $conds != '*' ) {
if ( is_array( $conds ) ) {
$this->mTrxPreCommitCallbacks[] = [ $callback, wfGetCaller() ];
} else {
// If no transaction is active, then make one for this callback
- $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
+ $this->startAtomic( __METHOD__ );
try {
call_user_func( $callback );
- $this->commit( __METHOD__ );
+ $this->endAtomic( __METHOD__ );
} catch ( Exception $e ) {
- $this->rollback( __METHOD__ );
+ $this->rollback( __METHOD__, self::FLUSHING_INTERNAL );
throw $e;
}
}
}
+ final public function setTransactionListener( $name, callable $callback = null ) {
+ if ( $callback ) {
+ $this->mTrxRecurringCallbacks[$name] = [ $callback, wfGetCaller() ];
+ } else {
+ unset( $this->mTrxRecurringCallbacks[$name] );
+ }
+ }
+
/**
- * Whether to disable running of post-commit callbacks
+ * Whether to disable running of post-COMMIT/ROLLBACK callbacks
*
* This method should not be used outside of Database/LoadBalancer
*
* @param bool $suppress
* @since 1.28
*/
- final public function setPostCommitCallbackSupression( $suppress ) {
- $this->suppressPostCommitCallbacks = $suppress;
+ final public function setTrxEndCallbackSuppression( $suppress ) {
+ $this->mTrxEndCallbacksSuppressed = $suppress;
}
/**
* @throws Exception
*/
public function runOnTransactionIdleCallbacks( $trigger ) {
- if ( $this->suppressPostCommitCallbacks ) {
+ if ( $this->mTrxEndCallbacksSuppressed ) {
return;
}
// Some callbacks may use startAtomic/endAtomic, so make sure
// their transactions are ended so other callbacks don't fail
if ( $this->trxLevel() ) {
- $this->rollback( __METHOD__ );
+ $this->rollback( __METHOD__, self::FLUSHING_INTERNAL );
}
}
}
}
}
+ /**
+ * Actually run any "transaction listener" callbacks.
+ *
+ * This method should not be used outside of Database/LoadBalancer
+ *
+ * @param integer $trigger IDatabase::TRIGGER_* constant
+ * @throws Exception
+ * @since 1.20
+ */
+ public function runTransactionListenerCallbacks( $trigger ) {
+ if ( $this->mTrxEndCallbacksSuppressed ) {
+ return;
+ }
+
+ /** @var Exception $e */
+ $e = null; // first exception
+
+ foreach ( $this->mTrxRecurringCallbacks as $callback ) {
+ try {
+ list( $phpCallback ) = $callback;
+ $phpCallback( $trigger, $this );
+ } catch ( Exception $ex ) {
+ MWExceptionHandler::logException( $ex );
+ $e = $e ?: $ex;
+ }
+ }
+
+ if ( $e instanceof Exception ) {
+ throw $e; // re-throw any first exception
+ }
+ }
+
final public function startAtomic( $fname = __METHOD__ ) {
if ( !$this->mTrxLevel ) {
$this->begin( $fname, self::TRANSACTION_INTERNAL );
- $this->mTrxAutomatic = true;
// If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
// in all changes being in one transaction to keep requests transactional.
if ( !$this->getFlag( DBO_TRX ) ) {
try {
$res = call_user_func_array( $callback, [ $this, $fname ] );
} catch ( Exception $e ) {
- $this->rollback( $fname );
+ $this->rollback( $fname, self::FLUSHING_INTERNAL );
throw $e;
}
$this->endAtomic( $fname );
// @TODO: make this an exception at some point
$msg = "$fname: Implicit transaction already active (from {$this->mTrxFname}).";
wfLogDBError( $msg );
+ wfWarn( $msg );
return; // join the main transaction set
}
} elseif ( $this->getFlag( DBO_TRX ) && $mode !== self::TRANSACTION_INTERNAL ) {
// @TODO: make this an exception at some point
- wfLogDBError( "$fname: Implicit transaction expected (DBO_TRX set)." );
+ $msg = "$fname: Implicit transaction expected (DBO_TRX set).";
+ wfLogDBError( $msg );
+ wfWarn( $msg );
return; // let any writes be in the main transaction
}
$this->mTrxTimestamp = microtime( true );
$this->mTrxFname = $fname;
$this->mTrxDoneWrites = false;
- $this->mTrxAutomatic = false;
+ $this->mTrxAutomatic = ( $mode === self::TRANSACTION_INTERNAL );
$this->mTrxAutomaticAtomic = false;
$this->mTrxAtomicLevels = [];
$this->mTrxShortId = wfRandomString( 12 );
$this->mTrxWriteDuration = 0.0;
+ $this->mTrxWriteQueryCount = 0;
+ $this->mTrxWriteAdjDuration = 0.0;
+ $this->mTrxWriteAdjQueryCount = 0;
$this->mTrxWriteCallers = [];
// First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
- // Get an estimate of the slave lag before then, treating estimate staleness
+ // Get an estimate of the replica DB lag before then, treating estimate staleness
// as lag itself just to be safe
$status = $this->getApproximateLagStatus();
- $this->mTrxSlaveLag = $status['lag'] + ( microtime( true ) - $status['since'] );
+ $this->mTrxReplicaLag = $status['lag'] + ( microtime( true ) - $status['since'] );
}
/**
return; // nothing to do
} elseif ( $this->mTrxAutomatic ) {
// @TODO: make this an exception at some point
- wfLogDBError( "$fname: Explicit commit of implicit transaction." );
+ $msg = "$fname: Explicit commit of implicit transaction.";
+ wfLogDBError( $msg );
+ wfWarn( $msg );
return; // wait for the main transaction set commit round
}
}
$this->assertOpen();
$this->runOnTransactionPreCommitCallbacks();
- $writeTime = $this->pendingWriteQueryDuration();
+ $writeTime = $this->pendingWriteQueryDuration( self::ESTIMATE_DB_APPLY );
$this->doCommit( $fname );
if ( $this->mTrxDoneWrites ) {
$this->mDoneWrites = microtime( true );
}
$this->runOnTransactionIdleCallbacks( self::TRIGGER_COMMIT );
+ $this->runTransactionListenerCallbacks( self::TRIGGER_COMMIT );
}
/**
$this->mTrxIdleCallbacks = []; // clear
$this->mTrxPreCommitCallbacks = []; // clear
$this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
+ $this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
}
/**
}
}
+ public function flushSnapshot( $fname = __METHOD__ ) {
+ if ( $this->writesOrCallbacksPending() || $this->explicitTrxActive() ) {
+ // This only flushes transactions to clear snapshots, not to write data
+ throw new DBUnexpectedError(
+ $this,
+ "$fname: Cannot COMMIT to clear snapshot because writes are pending."
+ );
+ }
+
+ $this->commit( $fname, self::FLUSHING_INTERNAL );
+ }
+
public function explicitTrxActive() {
return $this->mTrxLevel && ( $this->mTrxAtomicLevels || !$this->mTrxAutomatic );
}
}
}
- public function ping() {
+ public function ping( &$rtt = null ) {
+ // Avoid hitting the server if it was hit recently
if ( $this->isOpen() && ( microtime( true ) - $this->lastPing ) < self::PING_TTL ) {
- return true;
+ if ( !func_num_args() || $this->mRTTEstimate > 0 ) {
+ $rtt = $this->mRTTEstimate;
+ return true; // don't care about $rtt
+ }
}
- $ignoreErrors = true;
- $this->clearFlag( DBO_TRX, self::REMEMBER_PRIOR );
// This will reconnect if possible or return false if not
- $ok = (bool)$this->query( "SELECT 1 AS ping", __METHOD__, $ignoreErrors );
+ $this->clearFlag( DBO_TRX, self::REMEMBER_PRIOR );
+ $ok = ( $this->query( self::PING_QUERY, __METHOD__, true ) !== false );
$this->restoreFlags( self::RESTORE_PRIOR );
+ if ( $ok ) {
+ $rtt = $this->mRTTEstimate;
+ }
+
return $ok;
}
}
/**
- * Get the slave lag when the current transaction started
+ * Get the replica DB lag when the current transaction started
*
* This is useful when transactions might use snapshot isolation
* (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
*/
public function getTransactionLagStatus() {
return $this->mTrxLevel
- ? [ 'lag' => $this->mTrxSlaveLag, 'since' => $this->trxTimestamp() ]
+ ? [ 'lag' => $this->mTrxReplicaLag, 'since' => $this->trxTimestamp() ]
: null;
}
/**
- * Get a slave lag estimate for this server
+ * Get a replica DB lag estimate for this server
*
* @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
* @since 1.27
*/
public function getApproximateLagStatus() {
return [
- 'lag' => $this->getLBInfo( 'slave' ) ? $this->getLag() : 0,
+ 'lag' => $this->getLBInfo( 'replica' ) ? $this->getLag() : 0,
'since' => microtime( true )
];
}
dépôts / lhc / web / wiklou.git / blobdiff