* An interface for generating database load balancers
* @ingroup Database
*/
-abstract class LBFactory {
+abstract class LBFactory implements ILBFactory {
/** @var ChronologyProtector */
protected $chronProt;
/** @var object|string Class name or object With profileIn/profileOut methods */
/** @var string Agent name for query profiling */
protected $agent;
- const SHUTDOWN_NO_CHRONPROT = 0; // don't save DB positions at all
- const SHUTDOWN_CHRONPROT_ASYNC = 1; // save DB positions, but don't wait on remote DCs
- const SHUTDOWN_CHRONPROT_SYNC = 2; // save DB positions, waiting on all DCs
-
private static $loggerFields =
[ 'replLogger', 'connLogger', 'queryLogger', 'perfLogger' ];
- /**
- * Construct a manager of ILoadBalancer objects
- *
- * Sub-classes will extend the required keys in $conf with additional parameters
- *
- * @param $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]
- * @throws InvalidArgumentException
- */
public function __construct( array $conf ) {
$this->localDomain = isset( $conf['localDomain'] )
? DatabaseDomain::newFromId( $conf['localDomain'] )
$this->ticket = mt_rand();
}
- /**
- * Disables all load balancers. All connections are closed, and any attempt to
- * open a new connection will result in a DBAccessError.
- * @see ILoadBalancer::disable()
- */
public function destroy() {
$this->shutdown( self::SHUTDOWN_NO_CHRONPROT );
$this->forEachLBCallMethod( 'disable' );
}
+ public function shutdown(
+ $mode = self::SHUTDOWN_CHRONPROT_SYNC, callable $workCallback = null
+ ) {
+ $chronProt = $this->getChronologyProtector();
+ if ( $mode === self::SHUTDOWN_CHRONPROT_SYNC ) {
+ $this->shutdownChronologyProtector( $chronProt, $workCallback, 'sync' );
+ } elseif ( $mode === self::SHUTDOWN_CHRONPROT_ASYNC ) {
+ $this->shutdownChronologyProtector( $chronProt, null, 'async' );
+ }
+
+ $this->commitMasterChanges( __METHOD__ ); // sanity
+ }
+
/**
- * Create a new load balancer object. The resulting object will be untracked,
- * not chronology-protected, and the caller is responsible for cleaning it up.
- *
- * @param bool|string $domain Domain ID, or false for the current domain
- * @return ILoadBalancer
+ * @see ILBFactory::newMainLB()
+ * @param bool $domain
+ * @return LoadBalancer
*/
abstract public function newMainLB( $domain = false );
/**
- * Get a cached (tracked) load balancer object.
- *
- * @param bool|string $domain Domain ID, or false for the current domain
- * @return ILoadBalancer
+ * @see ILBFactory::getMainLB()
+ * @param bool $domain
+ * @return mixed
*/
abstract public function getMainLB( $domain = false );
/**
- * Create a new load balancer for external storage. The resulting object will be
- * untracked, not chronology-protected, and the caller is responsible for
- * cleaning it up.
- *
- * @param string $cluster External storage cluster, or false for core
- * @param bool|string $domain Domain ID, or false for the current domain
- * @return ILoadBalancer
+ * @see ILBFactory::newExternalLB()
+ * @param string $cluster
+ * @param bool $domain
+ * @return LoadBalancer
*/
- abstract protected function newExternalLB( $cluster, $domain = false );
+ abstract public function newExternalLB( $cluster, $domain = false );
/**
- * Get a cached (tracked) load balancer for external storage
- *
- * @param string $cluster External storage cluster, or false for core
- * @param bool|string $domain Domain ID, or false for the current domain
- * @return ILoadBalancer
+ * @see ILBFactory::getExternalLB()
+ * @param string $cluster
+ * @param bool $domain
+ * @return mixed
*/
abstract public function getExternalLB( $cluster, $domain = false );
- /**
- * 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.
- *
- * @param callable $callback
- * @param array $params
- */
- abstract public function forEachLB( $callback, array $params = [] );
-
- /**
- * Prepare all tracked load balancers for shutdown
- * @param integer $mode One of the class SHUTDOWN_* constants
- * @param callable|null $workCallback Work to mask ChronologyProtector writes
- */
- public function shutdown(
- $mode = self::SHUTDOWN_CHRONPROT_SYNC, callable $workCallback = null
- ) {
- $chronProt = $this->getChronologyProtector();
- if ( $mode === self::SHUTDOWN_CHRONPROT_SYNC ) {
- $this->shutdownChronologyProtector( $chronProt, $workCallback, 'sync' );
- } elseif ( $mode === self::SHUTDOWN_CHRONPROT_ASYNC ) {
- $this->shutdownChronologyProtector( $chronProt, null, 'async' );
- }
-
- $this->commitMasterChanges( __METHOD__ ); // sanity
- }
-
/**
* Call a method of each tracked load balancer
*
);
}
- /**
- * Commit all replica DB transactions so as to flush any REPEATABLE-READ or SSI snapshot
- *
- * @param string $fname Caller name
- * @since 1.28
- */
public function flushReplicaSnapshots( $fname = __METHOD__ ) {
$this->forEachLBCallMethod( 'flushReplicaSnapshots', [ $fname ] );
}
- /**
- * Commit on all connections. Done for two reasons:
- * 1. To commit changes to the masters.
- * 2. To release the snapshot on all connections, master and replica DB.
- * @param string $fname Caller name
- * @param array $options Options map:
- * - maxWriteDuration: abort if more than this much time was spent in write queries
- */
public function commitAll( $fname = __METHOD__, array $options = [] ) {
$this->commitMasterChanges( $fname, $options );
$this->forEachLBCallMethod( 'commitAll', [ $fname ] );
}
- /**
- * 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:
- * - commitMasterChanges()
- * - rollbackMasterChanges()
- * - commitAll()
- *
- * This allows for custom transaction rounds from any outer transaction scope.
- *
- * @param string $fname
- * @throws DBTransactionError
- * @since 1.28
- */
public function beginMasterChanges( $fname = __METHOD__ ) {
if ( $this->trxRoundId !== false ) {
throw new DBTransactionError(
$this->forEachLBCallMethod( 'beginMasterChanges', [ $fname ] );
}
- /**
- * Commit changes on all master connections
- * @param string $fname Caller name
- * @param array $options Options map:
- * - maxWriteDuration: abort if more than this much time was spent in write queries
- * @throws Exception
- */
public function commitMasterChanges( $fname = __METHOD__, array $options = [] ) {
if ( $this->trxRoundId !== false && $this->trxRoundId !== $fname ) {
throw new DBTransactionError(
"$fname: transaction round '{$this->trxRoundId}' still running."
);
}
+ /** @noinspection PhpUnusedLocalVariableInspection */
+ $scope = $this->getScopedPHPBehaviorForCommit(); // try to ignore client aborts
// Run pre-commit callbacks and suppress post-commit callbacks, aborting on failure
$this->forEachLBCallMethod( 'finalizeMasterChanges' );
$this->trxRoundId = false;
}
}
- /**
- * Rollback changes on all master connections
- * @param string $fname Caller name
- * @since 1.23
- */
public function rollbackMasterChanges( $fname = __METHOD__ ) {
$this->trxRoundId = false;
$this->forEachLBCallMethod( 'suppressTransactionEndCallbacks' );
}
}
- /**
- * Determine if any master connection has pending changes
- * @return bool
- * @since 1.23
- */
public function hasMasterChanges() {
$ret = false;
$this->forEachLB( function ( ILoadBalancer $lb ) use ( &$ret ) {
return $ret;
}
- /**
- * Detemine if any lagged replica DB connection was used
- * @return bool
- * @since 1.28
- */
public function laggedReplicaUsed() {
$ret = false;
$this->forEachLB( function ( ILoadBalancer $lb ) use ( &$ret ) {
return $ret;
}
- /**
- * Determine if any master connection has pending/written changes from this request
- * @param float $age How many seconds ago is "recent" [defaults to LB lag wait timeout]
- * @return bool
- * @since 1.27
- */
public function hasOrMadeRecentMasterChanges( $age = null ) {
$ret = false;
$this->forEachLB( function ( ILoadBalancer $lb ) use ( $age, &$ret ) {
return $ret;
}
- /**
- * 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.
- *
- * @param array $opts Optional 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
- * @throws DBReplicationWaitError If a timeout or error occured waiting on a DB cluster
- * @since 1.27
- */
public function waitForReplication( array $opts = [] ) {
$opts += [
'domain' => false,
}
}
- /**
- * Add a callback to be run in every call to waitForReplication() before waiting
- *
- * Callbacks must clear any transactions that they start
- *
- * @param string $name Callback name
- * @param callable|null $callback Use null to unset a callback
- * @since 1.28
- */
public function setWaitForReplicationListener( $name, callable $callback = null ) {
if ( $callback ) {
$this->replicationWaitCallbacks[$name] = $callback;
}
}
- /**
- * Get a token asserting that no transaction writes are active
- *
- * @param string $fname Caller name (e.g. __METHOD__)
- * @return mixed A value to pass to commitAndWaitForReplication()
- * @since 1.28
- */
public function getEmptyTransactionTicket( $fname ) {
if ( $this->hasMasterChanges() ) {
- $this->queryLogger->error( __METHOD__ . ": $fname does not have outer scope." );
+ $this->queryLogger->error( __METHOD__ . ": $fname does not have outer scope.\n" .
+ ( new RuntimeException() )->getTraceAsString() );
+
return null;
}
return $this->ticket;
}
- /**
- * Convenience method for safely running commitMasterChanges()/waitForReplication()
- *
- * This will commit and wait unless $ticket indicates it is unsafe to do so
- *
- * @param string $fname Caller name (e.g. __METHOD__)
- * @param mixed $ticket Result of getEmptyTransactionTicket()
- * @param array $opts Options to waitForReplication()
- * @throws DBReplicationWaitError
- * @since 1.28
- */
public function commitAndWaitForReplication( $fname, $ticket, array $opts = [] ) {
if ( $ticket !== $this->ticket ) {
- $this->perfLogger->error( __METHOD__ . ": $fname does not have outer scope." );
+ $this->perfLogger->error( __METHOD__ . ": $fname does not have outer scope.\n" .
+ ( new RuntimeException() )->getTraceAsString() );
+
return;
}
}
}
- /**
- * @param string $dbName DB master name (e.g. "db1052")
- * @return float|bool UNIX timestamp when client last touched the DB or false if not recent
- * @since 1.28
- */
public function getChronologyProtectorTouched( $dbName ) {
return $this->getChronologyProtector()->getTouched( $dbName );
}
- /**
- * Disable the ChronologyProtector for all load balancers
- *
- * This can be called at the start of special API entry points
- *
- * @since 1.27
- */
public function disableChronologyProtection() {
$this->getChronologyProtector()->setEnabled( false );
}
}
}
- /**
- * Set a new table prefix for the existing local domain ID for testing
- *
- * @param string $prefix
- * @since 1.28
- */
public function setDomainPrefix( $prefix ) {
$this->localDomain = new DatabaseDomain(
$this->localDomain->getDatabase(),
} );
}
- /**
- * Close all open database connections on all open load balancers.
- * @since 1.28
- */
public function closeAll() {
$this->forEachLBCallMethod( 'closeAll', [] );
}
- /**
- * @param string $agent Agent name for query profiling
- * @since 1.28
- */
public function setAgentName( $agent ) {
$this->agent = $agent;
}
- /**
- * Append ?cpPosTime parameter to a URL for ChronologyProtector purposes if needed
- *
- * Note that unlike cookies, this works accross domains
- *
- * @param string $url
- * @param float $time UNIX timestamp just before shutdown() was called
- * @return string
- * @since 1.28
- */
public function appendPreShutdownTimeAsQuery( $url, $time ) {
$usedCluster = 0;
$this->forEachLB( function ( ILoadBalancer $lb ) use ( &$usedCluster ) {
return strpos( $url, '?' ) === false ? "$url?cpPosTime=$time" : "$url&cpPosTime=$time";
}
- /**
- * @param array $info Map of fields, including:
- * - IPAddress : IP address
- * - UserAgent : User-Agent HTTP header
- * - ChronologyProtection : cookie/header value specifying ChronologyProtector usage
- * @since 1.28
- */
public function setRequestInfo( array $info ) {
$this->requestInfo = $info + $this->requestInfo;
}
+ /**
+ * Make PHP ignore user aborts/disconnects until the returned
+ * value leaves scope. This returns null and does nothing in CLI mode.
+ *
+ * @return ScopedCallback|null
+ */
+ final protected function getScopedPHPBehaviorForCommit() {
+ if ( PHP_SAPI != 'cli' ) { // http://bugs.php.net/bug.php?id=47540
+ $old = ignore_user_abort( true ); // avoid half-finished operations
+ return new ScopedCallback( function () use ( $old ) {
+ ignore_user_abort( $old );
+ } );
+ }
+
+ return null;
+ }
+
function __destruct() {
$this->destroy();
}
dépôts / lhc / web / wiklou.git / blobdiff