namespace Wikimedia\Rdbms;
use InvalidArgumentException;
+use UnexpectedValueException;
/**
* DBMasterPos class for MySQL/MariaDB
* - Binlog-based usage assumes single-source replication and non-hierarchical replication.
* - GTID-based usage allows getting/syncing with multi-source replication. It is assumed
* that GTID sets are complete (e.g. include all domains on the server).
+ *
+ * @see https://mariadb.com/kb/en/library/gtid/
+ * @see https://dev.mysql.com/doc/refman/5.6/en/replication-gtids-concepts.html
*/
class MySQLMasterPos implements DBMasterPos {
- /** @var string|null Binlog file base name */
- public $binlog;
- /** @var int[]|null Binglog file position tuple */
- public $pos;
- /** @var string[] GTID list */
- public $gtids = [];
+ /** @var int One of (BINARY_LOG, GTID_MYSQL, GTID_MARIA) */
+ private $style;
+ /** @var string|null Base name of all Binary Log files */
+ private $binLog;
+ /** @var int[]|null Binary Log position tuple (index number, event number) */
+ private $logPos;
+ /** @var string[] Map of (server_uuid/gtid_domain_id => GTID) */
+ private $gtids = [];
+ /** @var int|null Active GTID domain ID */
+ private $activeDomain;
+ /** @var int|null ID of the server were DB writes originate */
+ private $activeServerId;
+ /** @var string|null UUID of the server were DB writes originate */
+ private $activeServerUUID;
/** @var float UNIX timestamp */
- public $asOfTime = 0.0;
+ private $asOfTime = 0.0;
+
+ const BINARY_LOG = 'binary-log';
+ const GTID_MARIA = 'gtid-maria';
+ const GTID_MYSQL = 'gtid-mysql';
+
+ /** @var int Key name of the binary log index number of a position tuple */
+ const CORD_INDEX = 0;
+ /** @var int Key name of the binary log event number of a position tuple */
+ const CORD_EVENT = 1;
/**
* @param string $position One of (comma separated GTID list, <binlog file>/<integer>)
* @param float $asOfTime UNIX timestamp
*/
public function __construct( $position, $asOfTime ) {
+ $this->init( $position, $asOfTime );
+ }
+
+ /**
+ * @param string $position
+ * @param float $asOfTime
+ */
+ protected function init( $position, $asOfTime ) {
$m = [];
if ( preg_match( '!^(.+)\.(\d+)/(\d+)$!', $position, $m ) ) {
- $this->binlog = $m[1]; // ideally something like host name
- $this->pos = [ (int)$m[2], (int)$m[3] ];
+ $this->binLog = $m[1]; // ideally something like host name
+ $this->logPos = [ self::CORD_INDEX => (int)$m[2], self::CORD_EVENT => (int)$m[3] ];
+ $this->style = self::BINARY_LOG;
} else {
- $this->gtids = array_map( 'trim', explode( ',', $position ) );
+ $gtids = array_filter( array_map( 'trim', explode( ',', $position ) ) );
+ foreach ( $gtids as $gtid ) {
+ $components = self::parseGTID( $gtid );
+ if ( !$components ) {
+ throw new InvalidArgumentException( "Invalid GTID '$gtid'." );
+ }
+
+ list( $domain, $pos ) = $components;
+ if ( isset( $this->gtids[$domain] ) ) {
+ // For MySQL, handle the case where some past issue caused a gap in the
+ // executed GTID set, e.g. [last_purged+1,N-1] and [N+1,N+2+K]. Ignore the
+ // gap by using the GTID with the highest ending sequence number.
+ list( , $otherPos ) = self::parseGTID( $this->gtids[$domain] );
+ if ( $pos > $otherPos ) {
+ $this->gtids[$domain] = $gtid;
+ }
+ } else {
+ $this->gtids[$domain] = $gtid;
+ }
+
+ if ( is_int( $domain ) ) {
+ $this->style = self::GTID_MARIA; // gtid_domain_id
+ } else {
+ $this->style = self::GTID_MYSQL; // server_uuid
+ }
+ }
if ( !$this->gtids ) {
- throw new InvalidArgumentException( "GTID set should not be empty." );
+ throw new InvalidArgumentException( "GTID set cannot be empty." );
}
}
}
// Prefer GTID comparisons, which work with multi-tier replication
- $thisPosByDomain = $this->getGtidCoordinates();
- $thatPosByDomain = $pos->getGtidCoordinates();
+ $thisPosByDomain = $this->getActiveGtidCoordinates();
+ $thatPosByDomain = $pos->getActiveGtidCoordinates();
if ( $thisPosByDomain && $thatPosByDomain ) {
- $reached = true;
- // Check that this has positions GTE all of those in $pos for all domains in $pos
+ $comparisons = [];
+ // Check that this has positions reaching those in $pos for all domains in common
foreach ( $thatPosByDomain as $domain => $thatPos ) {
- $thisPos = isset( $thisPosByDomain[$domain] ) ? $thisPosByDomain[$domain] : -1;
- $reached = $reached && ( $thatPos <= $thisPos );
+ if ( isset( $thisPosByDomain[$domain] ) ) {
+ $comparisons[] = ( $thatPos <= $thisPosByDomain[$domain] );
+ }
}
-
- return $reached;
+ // Check that $this has a GTID for at least one domain also in $pos; due to MariaDB
+ // quirks, prior master switch-overs may result in inactive garbage GTIDs that cannot
+ // be cleaned up. Assume that the domains in both this and $pos cover the relevant
+ // active channels.
+ return ( $comparisons && !in_array( false, $comparisons, true ) );
}
// Fallback to the binlog file comparisons
}
// Prefer GTID comparisons, which work with multi-tier replication
- $thisPosDomains = array_keys( $this->getGtidCoordinates() );
- $thatPosDomains = array_keys( $pos->getGtidCoordinates() );
+ $thisPosDomains = array_keys( $this->getActiveGtidCoordinates() );
+ $thatPosDomains = array_keys( $pos->getActiveGtidCoordinates() );
if ( $thisPosDomains && $thatPosDomains ) {
- // Check that this has GTIDs for all domains in $pos
- return !array_diff( $thatPosDomains, $thisPosDomains );
+ // Check that $this has a GTID for at least one domain also in $pos; due to MariaDB
+ // quirks, prior master switch-overs may result in inactive garbage GTIDs that cannot
+ // easily be cleaned up. Assume that the domains in both this and $pos cover the
+ // relevant active channels.
+ return array_intersect( $thatPosDomains, $thisPosDomains ) ? true : false;
}
// Fallback to the binlog file comparisons
}
/**
- * @return string|null
+ * @return string|null Base name of binary log files
+ * @since 1.31
+ */
+ public function getLogName() {
+ return $this->gtids ? null : $this->binLog;
+ }
+
+ /**
+ * @return int[]|null Tuple of (binary log file number, event number)
+ * @since 1.31
+ */
+ public function getLogPosition() {
+ return $this->gtids ? null : $this->logPos;
+ }
+
+ /**
+ * @return string|null Name of the binary log file for this position
+ * @since 1.31
*/
public function getLogFile() {
- return $this->gtids ? null : "{$this->binlog}.{$this->pos[0]}";
+ return $this->gtids ? null : "{$this->binLog}.{$this->logPos[self::CORD_INDEX]}";
}
/**
- * @return string GTID set or <binlog file>/<position> (e.g db1034-bin.000976/843431247)
+ * @return string[] Map of (server_uuid/gtid_domain_id => GTID)
+ * @since 1.31
*/
- public function __toString() {
- return $this->gtids
- ? implode( ',', $this->gtids )
- : $this->getLogFile() . "/{$this->pos[1]}";
+ public function getGTIDs() {
+ return $this->gtids;
+ }
+
+ /**
+ * @param int|null $id @@gtid_domain_id of the active replication stream
+ * @since 1.31
+ */
+ public function setActiveDomain( $id ) {
+ $this->activeDomain = (int)$id;
+ }
+
+ /**
+ * @param int|null $id @@server_id of the server were writes originate
+ * @since 1.31
+ */
+ public function setActiveOriginServerId( $id ) {
+ $this->activeServerId = (int)$id;
+ }
+
+ /**
+ * @param string|null $id @@server_uuid of the server were writes originate
+ * @since 1.31
+ */
+ public function setActiveOriginServerUUID( $id ) {
+ $this->activeServerUUID = $id;
+ }
+
+ /**
+ * @param MySQLMasterPos $pos
+ * @param MySQLMasterPos $refPos
+ * @return string[] List of GTIDs from $pos that have domains in $refPos
+ * @since 1.31
+ */
+ public static function getCommonDomainGTIDs( MySQLMasterPos $pos, MySQLMasterPos $refPos ) {
+ return array_values(
+ array_intersect_key( $pos->gtids, $refPos->getActiveGtidCoordinates() )
+ );
}
/**
- * @note: this returns false for multi-source replication GTID sets
* @see https://mariadb.com/kb/en/mariadb/gtid
* @see https://dev.mysql.com/doc/refman/5.6/en/replication-gtids-concepts.html
- * @return array Map of (domain => integer position); possibly empty
+ * @return array Map of (server_uuid/gtid_domain_id => integer position); possibly empty
*/
- protected function getGtidCoordinates() {
+ protected function getActiveGtidCoordinates() {
$gtidInfos = [];
- foreach ( $this->gtids as $gtid ) {
- $m = [];
- // MariaDB style: <domain>-<server id>-<sequence number>
- if ( preg_match( '!^(\d+)-\d+-(\d+)$!', $gtid, $m ) ) {
- $gtidInfos[(int)$m[1]] = (int)$m[2];
- // MySQL style: <UUID domain>:<sequence number>
- } elseif ( preg_match( '!^(\w{8}-\w{4}-\w{4}-\w{4}-\w{12}):(\d+)$!', $gtid, $m ) ) {
- $gtidInfos[$m[1]] = (int)$m[2];
- } else {
- $gtidInfos = [];
- break; // unrecognized GTID
+
+ foreach ( $this->gtids as $domain => $gtid ) {
+ list( $domain, $pos, $server ) = self::parseGTID( $gtid );
+
+ $ignore = false;
+ // Filter out GTIDs from non-active replication domains
+ if ( $this->style === self::GTID_MARIA && $this->activeDomain !== null ) {
+ $ignore |= ( $domain !== $this->activeDomain );
+ }
+ // Likewise for GTIDs from non-active replication origin servers
+ if ( $this->style === self::GTID_MARIA && $this->activeServerId !== null ) {
+ $ignore |= ( $server !== $this->activeServerId );
+ } elseif ( $this->style === self::GTID_MYSQL && $this->activeServerUUID !== null ) {
+ $ignore |= ( $server !== $this->activeServerUUID );
}
+ if ( !$ignore ) {
+ $gtidInfos[$domain] = $pos;
+ }
}
return $gtidInfos;
}
+ /**
+ * @param string $id GTID
+ * @return array|null [domain ID or server UUID, sequence number, server ID/UUID] or null
+ */
+ protected static function parseGTID( $id ) {
+ $m = [];
+ if ( preg_match( '!^(\d+)-(\d+)-(\d+)$!', $id, $m ) ) {
+ // MariaDB style: <domain>-<server id>-<sequence number>
+ return [ (int)$m[1], (int)$m[3], (int)$m[2] ];
+ } elseif ( preg_match( '!^(\w{8}-\w{4}-\w{4}-\w{4}-\w{12}):(?:\d+-|)(\d+)$!', $id, $m ) ) {
+ // MySQL style: <server UUID>:<sequence number>-<sequence number>
+ // Normally, the first number should reflect the point (gtid_purged) where older
+ // binary logs where purged to save space. When doing comparisons, it may as well
+ // be 1 in that case. Assume that this is generally the situation.
+ return [ $m[1], (int)$m[2], $m[1] ];
+ }
+
+ return null;
+ }
+
/**
* @see https://dev.mysql.com/doc/refman/5.7/en/show-master-status.html
* @see https://dev.mysql.com/doc/refman/5.7/en/show-slave-status.html
- * @return array|bool (binlog, (integer file number, integer position)) or false
+ * @return array|bool Map of (binlog:<string>, pos:(<integer>, <integer>)) or false
*/
protected function getBinlogCoordinates() {
- return ( $this->binlog !== null && $this->pos !== null )
- ? [ 'binlog' => $this->binlog, 'pos' => $this->pos ]
+ return ( $this->binLog !== null && $this->logPos !== null )
+ ? [ 'binlog' => $this->binLog, 'pos' => $this->logPos ]
: false;
}
+
+ public function serialize() {
+ return serialize( [
+ 'position' => $this->__toString(),
+ 'activeDomain' => $this->activeDomain,
+ 'activeServerId' => $this->activeServerId,
+ 'activeServerUUID' => $this->activeServerUUID,
+ 'asOfTime' => $this->asOfTime
+ ] );
+ }
+
+ public function unserialize( $serialized ) {
+ $data = unserialize( $serialized );
+ if ( !is_array( $data ) ) {
+ throw new UnexpectedValueException( __METHOD__ . ": cannot unserialize position" );
+ }
+
+ $this->init( $data['position'], $data['asOfTime'] );
+ if ( isset( $data['activeDomain'] ) ) {
+ $this->setActiveDomain( $data['activeDomain'] );
+ }
+ if ( isset( $data['activeServerId'] ) ) {
+ $this->setActiveOriginServerId( $data['activeServerId'] );
+ }
+ if ( isset( $data['activeServerUUID'] ) ) {
+ $this->setActiveOriginServerUUID( $data['activeServerUUID'] );
+ }
+ }
+
+ /**
+ * @return string GTID set or <binary log file>/<position> (e.g db1034-bin.000976/843431247)
+ */
+ public function __toString() {
+ return $this->gtids
+ ? implode( ',', $this->gtids )
+ : $this->getLogFile() . "/{$this->logPos[self::CORD_EVENT]}";
+ }
}