MediaWiki  master
MySQLMasterPos.php
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1 <?php
2 
3 namespace Wikimedia\Rdbms;
4 
7 
19 class MySQLMasterPos implements DBMasterPos {
21  private $style;
23  private $binLog;
25  private $logPos;
27  private $gtids = [];
29  private $activeDomain;
31  private $activeServerId;
35  private $asOfTime = 0.0;
36 
37  const BINARY_LOG = 'binary-log';
38  const GTID_MARIA = 'gtid-maria';
39  const GTID_MYSQL = 'gtid-mysql';
40 
42  const CORD_INDEX = 0;
44  const CORD_EVENT = 1;
45 
50  public function __construct( $position, $asOfTime ) {
51  $this->init( $position, $asOfTime );
52  }
53 
58  protected function init( $position, $asOfTime ) {
59  $m = [];
60  if ( preg_match( '!^(.+)\.(\d+)/(\d+)$!', $position, $m ) ) {
61  $this->binLog = $m[1]; // ideally something like host name
62  $this->logPos = [ self::CORD_INDEX => (int)$m[2], self::CORD_EVENT => (int)$m[3] ];
63  $this->style = self::BINARY_LOG;
64  } else {
65  $gtids = array_filter( array_map( 'trim', explode( ',', $position ) ) );
66  foreach ( $gtids as $gtid ) {
67  $components = self::parseGTID( $gtid );
68  if ( !$components ) {
69  throw new InvalidArgumentException( "Invalid GTID '$gtid'." );
70  }
71 
72  list( $domain, $pos ) = $components;
73  if ( isset( $this->gtids[$domain] ) ) {
74  // For MySQL, handle the case where some past issue caused a gap in the
75  // executed GTID set, e.g. [last_purged+1,N-1] and [N+1,N+2+K]. Ignore the
76  // gap by using the GTID with the highest ending sequence number.
77  list( , $otherPos ) = self::parseGTID( $this->gtids[$domain] );
78  if ( $pos > $otherPos ) {
79  $this->gtids[$domain] = $gtid;
80  }
81  } else {
82  $this->gtids[$domain] = $gtid;
83  }
84 
85  if ( is_int( $domain ) ) {
86  $this->style = self::GTID_MARIA; // gtid_domain_id
87  } else {
88  $this->style = self::GTID_MYSQL; // server_uuid
89  }
90  }
91  if ( !$this->gtids ) {
92  throw new InvalidArgumentException( "GTID set cannot be empty." );
93  }
94  }
95 
96  $this->asOfTime = $asOfTime;
97  }
98 
99  public function asOfTime() {
100  return $this->asOfTime;
101  }
102 
103  public function hasReached( DBMasterPos $pos ) {
104  if ( !( $pos instanceof self ) ) {
105  throw new InvalidArgumentException( "Position not an instance of " . __CLASS__ );
106  }
107 
108  // Prefer GTID comparisons, which work with multi-tier replication
109  $thisPosByDomain = $this->getActiveGtidCoordinates();
110  $thatPosByDomain = $pos->getActiveGtidCoordinates();
111  if ( $thisPosByDomain && $thatPosByDomain ) {
112  $comparisons = [];
113  // Check that this has positions reaching those in $pos for all domains in common
114  foreach ( $thatPosByDomain as $domain => $thatPos ) {
115  if ( isset( $thisPosByDomain[$domain] ) ) {
116  $comparisons[] = ( $thatPos <= $thisPosByDomain[$domain] );
117  }
118  }
119  // Check that $this has a GTID for at least one domain also in $pos; due to MariaDB
120  // quirks, prior master switch-overs may result in inactive garbage GTIDs that cannot
121  // be cleaned up. Assume that the domains in both this and $pos cover the relevant
122  // active channels.
123  return ( $comparisons && !in_array( false, $comparisons, true ) );
124  }
125 
126  // Fallback to the binlog file comparisons
127  $thisBinPos = $this->getBinlogCoordinates();
128  $thatBinPos = $pos->getBinlogCoordinates();
129  if ( $thisBinPos && $thatBinPos && $thisBinPos['binlog'] === $thatBinPos['binlog'] ) {
130  return ( $thisBinPos['pos'] >= $thatBinPos['pos'] );
131  }
132 
133  // Comparing totally different binlogs does not make sense
134  return false;
135  }
136 
137  public function channelsMatch( DBMasterPos $pos ) {
138  if ( !( $pos instanceof self ) ) {
139  throw new InvalidArgumentException( "Position not an instance of " . __CLASS__ );
140  }
141 
142  // Prefer GTID comparisons, which work with multi-tier replication
143  $thisPosDomains = array_keys( $this->getActiveGtidCoordinates() );
144  $thatPosDomains = array_keys( $pos->getActiveGtidCoordinates() );
145  if ( $thisPosDomains && $thatPosDomains ) {
146  // Check that $this has a GTID for at least one domain also in $pos; due to MariaDB
147  // quirks, prior master switch-overs may result in inactive garbage GTIDs that cannot
148  // easily be cleaned up. Assume that the domains in both this and $pos cover the
149  // relevant active channels.
150  return array_intersect( $thatPosDomains, $thisPosDomains ) ? true : false;
151  }
152 
153  // Fallback to the binlog file comparisons
154  $thisBinPos = $this->getBinlogCoordinates();
155  $thatBinPos = $pos->getBinlogCoordinates();
156 
157  return ( $thisBinPos && $thatBinPos && $thisBinPos['binlog'] === $thatBinPos['binlog'] );
158  }
159 
164  public function getLogName() {
165  return $this->gtids ? null : $this->binLog;
166  }
167 
172  public function getLogPosition() {
173  return $this->gtids ? null : $this->logPos;
174  }
175 
180  public function getLogFile() {
181  return $this->gtids ? null : "{$this->binLog}.{$this->logPos[self::CORD_INDEX]}";
182  }
183 
188  public function getGTIDs() {
189  return $this->gtids;
190  }
191 
196  public function setActiveDomain( $id ) {
197  $this->activeDomain = (int)$id;
198  }
199 
204  public function setActiveOriginServerId( $id ) {
205  $this->activeServerId = (int)$id;
206  }
207 
212  public function setActiveOriginServerUUID( $id ) {
213  $this->activeServerUUID = $id;
214  }
215 
222  public static function getCommonDomainGTIDs( MySQLMasterPos $pos, MySQLMasterPos $refPos ) {
223  return array_values(
224  array_intersect_key( $pos->gtids, $refPos->getActiveGtidCoordinates() )
225  );
226  }
227 
233  protected function getActiveGtidCoordinates() {
234  $gtidInfos = [];
235 
236  foreach ( $this->gtids as $domain => $gtid ) {
237  list( $domain, $pos, $server ) = self::parseGTID( $gtid );
238 
239  $ignore = false;
240  // Filter out GTIDs from non-active replication domains
241  if ( $this->style === self::GTID_MARIA && $this->activeDomain !== null ) {
242  $ignore |= ( $domain !== $this->activeDomain );
243  }
244  // Likewise for GTIDs from non-active replication origin servers
245  if ( $this->style === self::GTID_MARIA && $this->activeServerId !== null ) {
246  $ignore |= ( $server !== $this->activeServerId );
247  } elseif ( $this->style === self::GTID_MYSQL && $this->activeServerUUID !== null ) {
248  $ignore |= ( $server !== $this->activeServerUUID );
249  }
250 
251  if ( !$ignore ) {
252  $gtidInfos[$domain] = $pos;
253  }
254  }
255 
256  return $gtidInfos;
257  }
258 
263  protected static function parseGTID( $id ) {
264  $m = [];
265  if ( preg_match( '!^(\d+)-(\d+)-(\d+)$!', $id, $m ) ) {
266  // MariaDB style: <domain>-<server id>-<sequence number>
267  return [ (int)$m[1], (int)$m[3], (int)$m[2] ];
268  } elseif ( preg_match( '!^(\w{8}-\w{4}-\w{4}-\w{4}-\w{12}):(?:\d+-|)(\d+)$!', $id, $m ) ) {
269  // MySQL style: <server UUID>:<sequence number>-<sequence number>
270  // Normally, the first number should reflect the point (gtid_purged) where older
271  // binary logs where purged to save space. When doing comparisons, it may as well
272  // be 1 in that case. Assume that this is generally the situation.
273  return [ $m[1], (int)$m[2], $m[1] ];
274  }
275 
276  return null;
277  }
278 
284  protected function getBinlogCoordinates() {
285  return ( $this->binLog !== null && $this->logPos !== null )
286  ? [ 'binlog' => $this->binLog, 'pos' => $this->logPos ]
287  : false;
288  }
289 
290  public function serialize() {
291  return serialize( [
292  'position' => $this->__toString(),
293  'activeDomain' => $this->activeDomain,
294  'activeServerId' => $this->activeServerId,
295  'activeServerUUID' => $this->activeServerUUID,
296  'asOfTime' => $this->asOfTime
297  ] );
298  }
299 
300  public function unserialize( $serialized ) {
302  if ( !is_array( $data ) ) {
303  throw new UnexpectedValueException( __METHOD__ . ": cannot unserialize position" );
304  }
305 
306  $this->init( $data['position'], $data['asOfTime'] );
307  if ( isset( $data['activeDomain'] ) ) {
308  $this->setActiveDomain( $data['activeDomain'] );
309  }
310  if ( isset( $data['activeServerId'] ) ) {
311  $this->setActiveOriginServerId( $data['activeServerId'] );
312  }
313  if ( isset( $data['activeServerUUID'] ) ) {
314  $this->setActiveOriginServerUUID( $data['activeServerUUID'] );
315  }
316  }
317 
321  public function __toString() {
322  return $this->gtids
323  ? implode( ',', $this->gtids )
324  : $this->getLogFile() . "/{$this->logPos[self::CORD_EVENT]}";
325  }
326 }
int $style
One of (BINARY_LOG, GTID_MYSQL, GTID_MARIA)
deferred txt A few of the database updates required by various functions here can be deferred until after the result page is displayed to the user For updating the view updating the linked to tables after a etc PHP does not yet have any way to tell the server to actually return and disconnect while still running these but it might have such a feature in the future We handle these by creating a deferred update object and putting those objects on a global list
Definition: deferred.txt:11
$data
Utility to generate mapping file used in mw.Title (phpCharToUpper.json)
__construct( $position, $asOfTime)
Apache License January AND DISTRIBUTION Definitions License shall mean the terms and conditions for use
int null $activeServerId
ID of the server were DB writes originate.
init( $position, $asOfTime)
string [] $gtids
Map of (server_uuid/gtid_domain_id => GTID)
static getCommonDomainGTIDs(MySQLMasterPos $pos, MySQLMasterPos $refPos)
null means default in associative array with keys and values unescaped Should be merged with default with a value of false meaning to suppress the attribute in associative array with keys and values unescaped noclasses just before the function returns a value If you return true
Definition: hooks.txt:1982
int [] null $logPos
Binary Log position tuple (index number, event number)
An object representing a master or replica DB position in a replicated setup.
Definition: DBMasterPos.php:12
this hook is for auditing only or null if authentication failed before getting that far or null if we can t even determine that When $user is not null
Definition: hooks.txt:780
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Definition: distributors.txt:9
DBMasterPos class for MySQL/MariaDB.
injection txt This is an overview of how MediaWiki makes use of dependency injection The design described here grew from the discussion of RFC T384 The term dependency this means that anything an object needs to operate should be injected from the the object itself should only know narrow no concrete implementation of the logic it relies on The requirement to inject everything typically results in an architecture that based on two main types of and essentially stateless service objects that use other service objects to operate on the value objects As of the beginning MediaWiki is only starting to use the DI approach Much of the code still relies on global state or direct resulting in a highly cyclical dependency which acts as the top level factory for services in MediaWiki which can be used to gain access to default instances of various services MediaWikiServices however also allows new services to be defined and default services to be redefined Services are defined or redefined by providing a callback the instantiator that will return a new instance of the service When it will create an instance of MediaWikiServices and populate it with the services defined in the files listed by thereby bootstrapping the DI framework Per $wgServiceWiringFiles lists includes ServiceWiring php
Definition: injection.txt:35
string null $binLog
Base name of all Binary Log files.
float $asOfTime
UNIX timestamp.
Bar style
foreach( $res as $row) $serialized
int null $activeDomain
Active GTID domain ID.
string null $activeServerUUID
UUID of the server were DB writes originate.