const PARSE_THRESHOLD_SEC = 1.0;
/** @var integer Lag safety margin when comparing root job times to last-refresh times */
const CLOCK_FUDGE = 10;
+ /** @var integer How many seconds to wait for slaves to catch up */
+ const LAG_WAIT_TIMEOUT = 15;
function __construct( Title $title, array $params ) {
parent::__construct( 'refreshLinks', $title, $params );
// Avoid the overhead of de-duplication when it would be pointless
$this->removeDuplicates = (
- // Master positions won't match
- !isset( $params['masterPos'] ) &&
// Ranges rarely will line up
!isset( $params['range'] ) &&
// Multiple pages per job make matches unlikely
// Job to update all (or a range of) backlink pages for a page
if ( !empty( $this->params['recursive'] ) ) {
+ // When the base job branches, wait for the slaves to catch up to the master.
+ // From then on, we know that any template changes at the time the base job was
+ // enqueued will be reflected in backlink page parses when the leaf jobs run.
+ if ( !isset( $params['range'] ) ) {
+ try {
+ wfGetLBFactory()->waitForReplication( [
+ 'wiki' => wfWikiID(),
+ 'timeout' => self::LAG_WAIT_TIMEOUT
+ ] );
+ } catch ( DBReplicationWaitError $e ) { // only try so hard
+ $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
+ $stats->increment( 'refreshlinks.lag_wait_failed' );
+ }
+ }
// Carry over information for de-duplication
$extraParams = $this->getRootJobParams();
- // Avoid slave lag when fetching templates.
- // When the outermost job is run, we know that the caller that enqueued it must have
- // committed the relevant changes to the DB by now. At that point, record the master
- // position and pass it along as the job recursively breaks into smaller range jobs.
- // Hopefully, when leaf jobs are popped, the slaves will have reached that position.
- if ( isset( $this->params['masterPos'] ) ) {
- $extraParams['masterPos'] = $this->params['masterPos'];
- } elseif ( wfGetLB()->getServerCount() > 1 ) {
- $extraParams['masterPos'] = wfGetLB()->getMasterPos();
- } else {
- $extraParams['masterPos'] = false;
- }
$extraParams['triggeredRecursive'] = true;
// Convert this into no more than $wgUpdateRowsPerJob RefreshLinks per-title
// jobs and possibly a recursive RefreshLinks job for the rest of the backlinks
JobQueueGroup::singleton()->push( $jobs );
// Job to update link tables for a set of titles
} elseif ( isset( $this->params['pages'] ) ) {
- $this->waitForMasterPosition();
foreach ( $this->params['pages'] as $pageId => $nsAndKey ) {
list( $ns, $dbKey ) = $nsAndKey;
$this->runForTitle( Title::makeTitleSafe( $ns, $dbKey ) );
}
// Job to update link tables for a given title
} else {
- $this->waitForMasterPosition();
$this->runForTitle( $this->title );
}
return true;
}
- protected function waitForMasterPosition() {
- if ( !empty( $this->params['masterPos'] ) && wfGetLB()->getServerCount() > 1 ) {
- // Wait for the current/next slave DB handle to catch up to the master.
- // This way, we get the correct page_latest for templates or files that just
- // changed milliseconds ago, having triggered this job to begin with.
- wfGetLB()->waitFor( $this->params['masterPos'] );
- }
- }
-
/**
* @param Title $title
* @return bool
*/
protected function runForTitle( Title $title ) {
+ $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
+
$page = WikiPage::factory( $title );
+ $page->loadPageData( WikiPage::READ_LATEST );
+
+ // Serialize links updates by page ID so they see each others' changes
+ $scopedLock = LinksUpdate::acquirePageLock( wfGetDB( DB_MASTER ), $page->getId(), 'job' );
+ // Get the latest ID *after* acquirePageLock() flushed the transaction.
+ // This is used to detect edits/moves after loadPageData() but before the scope lock.
+ // The works around the chicken/egg problem of determining the scope lock key.
+ $latest = $title->getLatestRevID( Title::GAID_FOR_UPDATE );
+
if ( !empty( $this->params['triggeringRevisionId'] ) ) {
// Fetch the specified revision; lockAndGetLatest() below detects if the page
// was edited since and aborts in order to avoid corrupting the link tables
$revision = Revision::newFromTitle( $title, false, Revision::READ_LATEST );
}
- $stats = MediaWikiServices::getInstance()->getStatsdDataFactory();
-
if ( !$revision ) {
$stats->increment( 'refreshlinks.rev_not_found' );
$this->setLastError( "Revision not found for {$title->getPrefixedDBkey()}" );
return false; // just deleted?
- } elseif ( !$revision->isCurrent() ) {
- // If the revision isn't current, there's no point in doing a bunch
- // of work just to fail at the lockAndGetLatest() check later.
+ } elseif ( $revision->getId() != $latest || $revision->getPage() !== $page->getId() ) {
+ // Do not clobber over newer updates with older ones. If all jobs where FIFO and
+ // serialized, it would be OK to update links based on older revisions since it
+ // would eventually get to the latest. Since that is not the case (by design),
+ // only update the link tables to a state matching the current revision's output.
$stats->increment( 'refreshlinks.rev_not_current' );
$this->setLastError( "Revision {$revision->getId()} is not current" );
return false;
}
}
- $latestNow = $page->lockAndGetLatest();
- if ( !$latestNow || $revision->getId() != $latestNow ) {
- // Do not clobber over newer updates with older ones. If all jobs where FIFO and
- // serialized, it would be OK to update links based on older revisions since it
- // would eventually get to the latest. Since that is not the case (by design),
- // only update the link tables to a state matching the current revision's output.
- $stats->increment( 'refreshlinks.rev_cas_failure' );
- $this->setLastError( "page_latest changed from {$revision->getId()} to $latestNow" );
- return false;
- }
-
DataUpdate::runUpdates( $updates );
InfoAction::invalidateCache( $title );
dépôts / lhc / web / wiklou.git / blobdiff