* @ingroup FileBackend
*/
+use Wikimedia\Timestamp\ConvertibleTimestamp;
+
/**
* @brief Proxy backend that mirrors writes to several internal backends.
*
/** @var bool */
protected $asyncWrites = false;
- /* Possible internal backend consistency checks */
+ /** @var int Compare file sizes among backends */
const CHECK_SIZE = 1;
+ /** @var int Compare file mtimes among backends */
const CHECK_TIME = 2;
+ /** @var int Compare file hashes among backends */
const CHECK_SHA1 = 4;
/**
$mbe = $this->backends[$this->masterIndex]; // convenience
- // Try to lock those files for the scope of this function...
- $scopeLock = null;
+ // Acquire any locks as needed
if ( empty( $opts['nonLocking'] ) ) {
- // Try to lock those files for the scope of this function...
/** @noinspection PhpUnusedLocalVariableInspection */
$scopeLock = $this->getScopedLocksForOps( $ops, $status );
if ( !$status->isOK() ) {
// Clear any cache entries (after locks acquired)
$this->clearCache();
$opts['preserveCache'] = true; // only locked files are cached
- // Get the list of paths to read/write...
+ // Get the list of paths to read/write
$relevantPaths = $this->fileStoragePathsForOps( $ops );
- // Check if the paths are valid and accessible on all backends...
+ // Check if the paths are valid and accessible on all backends
$status->merge( $this->accessibilityCheck( $relevantPaths ) );
if ( !$status->isOK() ) {
return $status; // abort
}
- // Do a consistency check to see if the backends are consistent...
+ // Do a consistency check to see if the backends are consistent
$syncStatus = $this->consistencyCheck( $relevantPaths );
if ( !$syncStatus->isOK() ) {
- wfDebugLog( 'FileOperation', static::class .
- " failed sync check: " . FormatJson::encode( $relevantPaths ) );
- // Try to resync the clone backends to the master on the spot...
- if ( $this->autoResync === false
- || !$this->resyncFiles( $relevantPaths, $this->autoResync )->isOK()
+ $this->logger->error(
+ __METHOD__ . ": failed sync check: " . FormatJson::encode( $relevantPaths )
+ );
+ // Try to resync the clone backends to the master on the spot
+ if (
+ $this->autoResync === false ||
+ !$this->resyncFiles( $relevantPaths, $this->autoResync )->isOK()
) {
$status->merge( $syncStatus );
return $status; // abort
}
}
- // Actually attempt the operation batch on the master backend...
+ // Actually attempt the operation batch on the master backend
$realOps = $this->substOpBatchPaths( $ops, $mbe );
$masterStatus = $mbe->doOperations( $realOps, $opts );
$status->merge( $masterStatus );
// Bind $scopeLock to the callback to preserve locks
DeferredUpdates::addCallableUpdate(
function () use ( $backend, $realOps, $opts, $scopeLock, $relevantPaths ) {
- wfDebugLog( 'FileOperationReplication',
+ $this->logger->error(
"'{$backend->getName()}' async replication; paths: " .
- FormatJson::encode( $relevantPaths ) );
+ FormatJson::encode( $relevantPaths )
+ );
$backend->doOperations( $realOps, $opts );
}
);
} else {
- wfDebugLog( 'FileOperationReplication',
+ $this->logger->error(
"'{$backend->getName()}' sync replication; paths: " .
- FormatJson::encode( $relevantPaths ) );
+ FormatJson::encode( $relevantPaths )
+ );
$status->merge( $backend->doOperations( $realOps, $opts ) );
}
}
/**
* Check that a set of files are consistent across all internal backends
*
+ * This method should only be called if the files are locked or the backend
+ * is in read-only mode
+ *
* @param array $paths List of storage paths
* @return StatusValue
*/
return $status; // skip checks
}
- // Preload all of the stat info in as few round trips as possible...
+ // Preload all of the stat info in as few round trips as possible
foreach ( $this->backends as $backend ) {
$realPaths = $this->substPaths( $paths, $backend );
$backend->preloadFileStat( [ 'srcs' => $realPaths, 'latest' => true ] );
}
- $mBackend = $this->backends[$this->masterIndex];
foreach ( $paths as $path ) {
$params = [ 'src' => $path, 'latest' => true ];
- $mParams = $this->substOpPaths( $params, $mBackend );
- // Stat the file on the 'master' backend
- $mStat = $mBackend->getFileStat( $mParams );
+ // Get the state of the file on the master backend
+ $masterBackend = $this->backends[$this->masterIndex];
+ $masterParams = $this->substOpPaths( $params, $masterBackend );
+ $masterStat = $masterBackend->getFileStat( $masterParams );
+ if ( $masterStat === self::UNKNOWN ) {
+ $status->fatal( 'backend-fail-stat', $path );
+ continue;
+ }
if ( $this->syncChecks & self::CHECK_SHA1 ) {
- $mSha1 = $mBackend->getFileSha1Base36( $mParams );
+ $masterSha1 = $masterBackend->getFileSha1Base36( $masterParams );
+ if ( ( $masterSha1 !== false ) !== (bool)$masterStat ) {
+ $status->fatal( 'backend-fail-hash', $path );
+ continue;
+ }
} else {
- $mSha1 = false;
+ $masterSha1 = null; // unused
}
+
// Check if all clone backends agree with the master...
- foreach ( $this->backends as $index => $cBackend ) {
+ foreach ( $this->backends as $index => $cloneBackend ) {
if ( $index === $this->masterIndex ) {
continue; // master
}
- $cParams = $this->substOpPaths( $params, $cBackend );
- $cStat = $cBackend->getFileStat( $cParams );
- if ( $mStat ) { // file is in master
- if ( !$cStat ) { // file should exist
+
+ // Get the state of the file on the clone backend
+ $cloneParams = $this->substOpPaths( $params, $cloneBackend );
+ $cloneStat = $cloneBackend->getFileStat( $cloneParams );
+
+ if ( $masterStat ) {
+ // File exists in the master backend
+ if ( !$cloneStat ) {
+ // File is missing from the clone backend
$status->fatal( 'backend-fail-synced', $path );
- continue;
- }
- if ( ( $this->syncChecks & self::CHECK_SIZE )
- && $cStat['size'] != $mStat['size']
- ) { // wrong size
+ } elseif (
+ ( $this->syncChecks & self::CHECK_SIZE ) &&
+ $cloneStat['size'] !== $masterStat['size']
+ ) {
+ // File in the clone backend is different
$status->fatal( 'backend-fail-synced', $path );
- continue;
- }
- if ( $this->syncChecks & self::CHECK_TIME ) {
- $mTs = wfTimestamp( TS_UNIX, $mStat['mtime'] );
- $cTs = wfTimestamp( TS_UNIX, $cStat['mtime'] );
- if ( abs( $mTs - $cTs ) > 30 ) { // outdated file somewhere
- $status->fatal( 'backend-fail-synced', $path );
- continue;
- }
- }
- if (
+ } elseif (
+ ( $this->syncChecks & self::CHECK_TIME ) &&
+ abs(
+ ConvertibleTimestamp::convert( TS_UNIX, $masterStat['mtime'] ) -
+ ConvertibleTimestamp::convert( TS_UNIX, $cloneStat['mtime'] )
+ ) > 30
+ ) {
+ // File in the clone backend is significantly newer or older
+ $status->fatal( 'backend-fail-synced', $path );
+ } elseif (
( $this->syncChecks & self::CHECK_SHA1 ) &&
- $cBackend->getFileSha1Base36( $cParams ) !== $mSha1
- ) { // wrong SHA1
+ $cloneBackend->getFileSha1Base36( $cloneParams ) !== $masterSha1
+ ) {
+ // File in the clone backend is different
+ $status->fatal( 'backend-fail-synced', $path );
+ }
+ } else {
+ // File does not exist in the master backend
+ if ( $cloneStat ) {
+ // Stray file exists in the clone backend
$status->fatal( 'backend-fail-synced', $path );
- continue;
}
- } elseif ( $cStat ) { // file is not in master; file should not exist
- $status->fatal( 'backend-fail-synced', $path );
}
}
}
* Check that a set of files are consistent across all internal backends
* and re-synchronize those files against the "multi master" if needed.
*
+ * This method should only be called if the files are locked
+ *
* @param array $paths List of storage paths
* @param string|bool $resyncMode False, True, or "conservative"; see __construct()
* @return StatusValue
public function resyncFiles( array $paths, $resyncMode = true ) {
$status = $this->newStatus();
- $mBackend = $this->backends[$this->masterIndex];
+ $fname = __METHOD__;
foreach ( $paths as $path ) {
- $mPath = $this->substPaths( $path, $mBackend );
- $mSha1 = $mBackend->getFileSha1Base36( [ 'src' => $mPath, 'latest' => true ] );
- $mStat = $mBackend->getFileStat( [ 'src' => $mPath, 'latest' => true ] );
- if ( $mStat === null || ( $mSha1 !== false && !$mStat ) ) { // sanity
- $status->fatal( 'backend-fail-internal', $this->name );
- wfDebugLog( 'FileOperation', __METHOD__
- . ': File is not available on the master backend' );
- continue; // file is not available on the master backend...
+ $params = [ 'src' => $path, 'latest' => true ];
+ // Get the state of the file on the master backend
+ $masterBackend = $this->backends[$this->masterIndex];
+ $masterParams = $this->substOpPaths( $params, $masterBackend );
+ $masterPath = $masterParams['src'];
+ $masterStat = $masterBackend->getFileStat( $masterParams );
+ if ( $masterStat === self::UNKNOWN ) {
+ $status->fatal( 'backend-fail-stat', $path );
+ $this->logger->error( "$fname: file '$masterPath' is not available" );
+ continue;
+ }
+ $masterSha1 = $masterBackend->getFileSha1Base36( $masterParams );
+ if ( ( $masterSha1 !== false ) !== (bool)$masterStat ) {
+ $status->fatal( 'backend-fail-hash', $path );
+ $this->logger->error( "$fname: file '$masterPath' hash does not match stat" );
+ continue;
}
+
// Check of all clone backends agree with the master...
- foreach ( $this->backends as $index => $cBackend ) {
+ foreach ( $this->backends as $index => $cloneBackend ) {
if ( $index === $this->masterIndex ) {
continue; // master
}
- $cPath = $this->substPaths( $path, $cBackend );
- $cSha1 = $cBackend->getFileSha1Base36( [ 'src' => $cPath, 'latest' => true ] );
- $cStat = $cBackend->getFileStat( [ 'src' => $cPath, 'latest' => true ] );
- if ( $cStat === null || ( $cSha1 !== false && !$cStat ) ) { // sanity
- $status->fatal( 'backend-fail-internal', $cBackend->getName() );
- wfDebugLog( 'FileOperation', __METHOD__ .
- ': File is not available on the clone backend' );
- continue; // file is not available on the clone backend...
+
+ // Get the state of the file on the clone backend
+ $cloneParams = $this->substOpPaths( $params, $cloneBackend );
+ $clonePath = $cloneParams['src'];
+ $cloneStat = $cloneBackend->getFileStat( $cloneParams );
+ if ( $cloneStat === self::UNKNOWN ) {
+ $status->fatal( 'backend-fail-stat', $path );
+ $this->logger->error( "$fname: file '$clonePath' is not available" );
+ continue;
}
- if ( $mSha1 === $cSha1 ) {
- // already synced; nothing to do
- } elseif ( $mSha1 !== false ) { // file is in master
- if ( $resyncMode === 'conservative'
- && $cStat && $cStat['mtime'] > $mStat['mtime']
+ $cloneSha1 = $cloneBackend->getFileSha1Base36( $cloneParams );
+ if ( ( $cloneSha1 !== false ) !== (bool)$cloneStat ) {
+ $status->fatal( 'backend-fail-hash', $path );
+ $this->logger->error( "$fname: file '$clonePath' hash does not match stat" );
+ continue;
+ }
+
+ if ( $masterSha1 === $cloneSha1 ) {
+ // File is either the same in both backends or absent from both backends
+ $this->logger->debug( "$fname: file '$clonePath' matches '$masterPath'" );
+ } elseif ( $masterSha1 !== false ) {
+ // File is either missing from or different in the clone backend
+ if (
+ $resyncMode === 'conservative' &&
+ $cloneStat &&
+ $cloneStat['mtime'] > $masterStat['mtime']
) {
+ // Do not replace files with older ones; reduces the risk of data loss
$status->fatal( 'backend-fail-synced', $path );
- continue; // don't rollback data
+ } else {
+ // Copy the master backend file to the clone backend in overwrite mode
+ $fsFile = $masterBackend->getLocalReference( $masterParams );
+ $status->merge( $cloneBackend->quickStore( [
+ 'src' => $fsFile,
+ 'dst' => $clonePath
+ ] ) );
}
- $fsFile = $mBackend->getLocalReference(
- [ 'src' => $mPath, 'latest' => true ] );
- $status->merge( $cBackend->quickStore(
- [ 'src' => $fsFile->getPath(), 'dst' => $cPath ]
- ) );
- } elseif ( $mStat === false ) { // file is not in master
+ } elseif ( $masterStat === false ) {
+ // Stray file exists in the clone backend
if ( $resyncMode === 'conservative' ) {
+ // Do not delete stray files; reduces the risk of data loss
$status->fatal( 'backend-fail-synced', $path );
- continue; // don't delete data
+ } else {
+ // Delete the stay file from the clone backend
+ $status->merge( $cloneBackend->quickDelete( [ 'src' => $clonePath ] ) );
}
- $status->merge( $cBackend->quickDelete( [ 'src' => $cPath ] ) );
}
}
}
if ( !$status->isOK() ) {
- wfDebugLog( 'FileOperation', static::class .
- " failed to resync: " . FormatJson::encode( $paths ) );
+ $this->logger->error( "$fname: failed to resync: " . FormatJson::encode( $paths ) );
}
return $status;
protected function doQuickOperationsInternal( array $ops ) {
$status = $this->newStatus();
- // Do the operations on the master backend; setting StatusValue fields...
+ // Do the operations on the master backend; setting StatusValue fields
$realOps = $this->substOpBatchPaths( $ops, $this->backends[$this->masterIndex] );
$masterStatus = $this->backends[$this->masterIndex]->doQuickOperations( $realOps );
$status->merge( $masterStatus );
dépôts / lhc / web / wiklou.git / commitdiff