%PDF-
%PDF-
Mini Shell
Mini Shell
<?php
/**
* Moves blobs indexed by trackBlobs.php to a specified list of destination
* clusters, and recompresses them in the process.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup Maintenance ExternalStorage
*/
use MediaWiki\Logger\LegacyLogger;
$optionsWithArgs = RecompressTracked::getOptionsWithArgs();
require __DIR__ . '/../commandLine.inc';
if ( count( $args ) < 1 ) {
echo "Usage: php recompressTracked.php [options] <cluster> [... <cluster>...]
Moves blobs indexed by trackBlobs.php to a specified list of destination clusters,
and recompresses them in the process. Restartable.
Options:
--procs <procs> Set the number of child processes (default 1)
--copy-only Copy only, do not update the text table. Restart
without this option to complete.
--debug-log <file> Log debugging data to the specified file
--info-log <file> Log progress messages to the specified file
--critical-log <file> Log error messages to the specified file
";
exit( 1 );
}
$job = RecompressTracked::newFromCommandLine( $args, $options );
$job->execute();
/**
* Maintenance script that moves blobs indexed by trackBlobs.php to a specified
* list of destination clusters, and recompresses them in the process.
*
* @ingroup Maintenance ExternalStorage
*/
class RecompressTracked {
public $destClusters;
public $batchSize = 1000;
public $orphanBatchSize = 1000;
public $reportingInterval = 10;
public $numProcs = 1;
public $useDiff, $pageBlobClass, $orphanBlobClass;
public $slavePipes, $slaveProcs, $prevSlaveId;
public $copyOnly = false;
public $isChild = false;
public $slaveId = false;
public $noCount = false;
public $debugLog, $infoLog, $criticalLog;
public $store;
private static $optionsWithArgs = array(
'procs',
'slave-id',
'debug-log',
'info-log',
'critical-log'
);
private static $cmdLineOptionMap = array(
'no-count' => 'noCount',
'procs' => 'numProcs',
'copy-only' => 'copyOnly',
'child' => 'isChild',
'slave-id' => 'slaveId',
'debug-log' => 'debugLog',
'info-log' => 'infoLog',
'critical-log' => 'criticalLog',
);
static function getOptionsWithArgs() {
return self::$optionsWithArgs;
}
static function newFromCommandLine( $args, $options ) {
$jobOptions = array( 'destClusters' => $args );
foreach ( self::$cmdLineOptionMap as $cmdOption => $classOption ) {
if ( isset( $options[$cmdOption] ) ) {
$jobOptions[$classOption] = $options[$cmdOption];
}
}
return new self( $jobOptions );
}
function __construct( $options ) {
foreach ( $options as $name => $value ) {
$this->$name = $value;
}
$this->store = new ExternalStoreDB;
if ( !$this->isChild ) {
$GLOBALS['wgDebugLogPrefix'] = "RCT M: ";
} elseif ( $this->slaveId !== false ) {
$GLOBALS['wgDebugLogPrefix'] = "RCT {$this->slaveId}: ";
}
$this->useDiff = function_exists( 'xdiff_string_bdiff' );
$this->pageBlobClass = $this->useDiff ? 'DiffHistoryBlob' : 'ConcatenatedGzipHistoryBlob';
$this->orphanBlobClass = 'ConcatenatedGzipHistoryBlob';
}
function debug( $msg ) {
wfDebug( "$msg\n" );
if ( $this->debugLog ) {
$this->logToFile( $msg, $this->debugLog );
}
}
function info( $msg ) {
echo "$msg\n";
if ( $this->infoLog ) {
$this->logToFile( $msg, $this->infoLog );
}
}
function critical( $msg ) {
echo "$msg\n";
if ( $this->criticalLog ) {
$this->logToFile( $msg, $this->criticalLog );
}
}
function logToFile( $msg, $file ) {
$header = '[' . date( 'd\TH:i:s' ) . '] ' . wfHostname() . ' ' . posix_getpid();
if ( $this->slaveId !== false ) {
$header .= "({$this->slaveId})";
}
$header .= ' ' . wfWikiID();
LegacyLogger::emit( sprintf( "%-50s %s\n", $header, $msg ), $file );
}
/**
* Wait until the selected slave has caught up to the master.
* This allows us to use the slave for things that were committed in a
* previous part of this batch process.
*/
function syncDBs() {
$dbw = wfGetDB( DB_MASTER );
$dbr = wfGetDB( DB_SLAVE );
$pos = $dbw->getMasterPos();
$dbr->masterPosWait( $pos, 100000 );
}
/**
* Execute parent or child depending on the isChild option
*/
function execute() {
if ( $this->isChild ) {
$this->executeChild();
} else {
$this->executeParent();
}
}
/**
* Execute the parent process
*/
function executeParent() {
if ( !$this->checkTrackingTable() ) {
return;
}
$this->syncDBs();
$this->startSlaveProcs();
$this->doAllPages();
$this->doAllOrphans();
$this->killSlaveProcs();
}
/**
* Make sure the tracking table exists and isn't empty
* @return bool
*/
function checkTrackingTable() {
$dbr = wfGetDB( DB_SLAVE );
if ( !$dbr->tableExists( 'blob_tracking' ) ) {
$this->critical( "Error: blob_tracking table does not exist" );
return false;
}
$row = $dbr->selectRow( 'blob_tracking', '*', false, __METHOD__ );
if ( !$row ) {
$this->info( "Warning: blob_tracking table contains no rows, skipping this wiki." );
return false;
}
return true;
}
/**
* Start the worker processes.
* These processes will listen on stdin for commands.
* This necessary because text recompression is slow: loading, compressing and
* writing are all slow.
*/
function startSlaveProcs() {
$cmd = 'php ' . wfEscapeShellArg( __FILE__ );
foreach ( self::$cmdLineOptionMap as $cmdOption => $classOption ) {
if ( $cmdOption == 'slave-id' ) {
continue;
} elseif ( in_array( $cmdOption, self::$optionsWithArgs ) && isset( $this->$classOption ) ) {
$cmd .= " --$cmdOption " . wfEscapeShellArg( $this->$classOption );
} elseif ( $this->$classOption ) {
$cmd .= " --$cmdOption";
}
}
$cmd .= ' --child' .
' --wiki ' . wfEscapeShellArg( wfWikiID() ) .
' ' . call_user_func_array( 'wfEscapeShellArg', $this->destClusters );
$this->slavePipes = $this->slaveProcs = array();
for ( $i = 0; $i < $this->numProcs; $i++ ) {
$pipes = false;
$spec = array(
array( 'pipe', 'r' ),
array( 'file', 'php://stdout', 'w' ),
array( 'file', 'php://stderr', 'w' )
);
wfSuppressWarnings();
$proc = proc_open( "$cmd --slave-id $i", $spec, $pipes );
wfRestoreWarnings();
if ( !$proc ) {
$this->critical( "Error opening slave process: $cmd" );
exit( 1 );
}
$this->slaveProcs[$i] = $proc;
$this->slavePipes[$i] = $pipes[0];
}
$this->prevSlaveId = -1;
}
/**
* Gracefully terminate the child processes
*/
function killSlaveProcs() {
$this->info( "Waiting for slave processes to finish..." );
for ( $i = 0; $i < $this->numProcs; $i++ ) {
$this->dispatchToSlave( $i, 'quit' );
}
for ( $i = 0; $i < $this->numProcs; $i++ ) {
$status = proc_close( $this->slaveProcs[$i] );
if ( $status ) {
$this->critical( "Warning: child #$i exited with status $status" );
}
}
$this->info( "Done." );
}
/**
* Dispatch a command to the next available slave.
* This may block until a slave finishes its work and becomes available.
*/
function dispatch( /*...*/ ) {
$args = func_get_args();
$pipes = $this->slavePipes;
$numPipes = stream_select( $x = array(), $pipes, $y = array(), 3600 );
if ( !$numPipes ) {
$this->critical( "Error waiting to write to slaves. Aborting" );
exit( 1 );
}
for ( $i = 0; $i < $this->numProcs; $i++ ) {
$slaveId = ( $i + $this->prevSlaveId + 1 ) % $this->numProcs;
if ( isset( $pipes[$slaveId] ) ) {
$this->prevSlaveId = $slaveId;
$this->dispatchToSlave( $slaveId, $args );
return;
}
}
$this->critical( "Unreachable" );
exit( 1 );
}
/**
* Dispatch a command to a specified slave
* @param int $slaveId
* @param array|string $args
*/
function dispatchToSlave( $slaveId, $args ) {
$args = (array)$args;
$cmd = implode( ' ', $args );
fwrite( $this->slavePipes[$slaveId], "$cmd\n" );
}
/**
* Move all tracked pages to the new clusters
*/
function doAllPages() {
$dbr = wfGetDB( DB_SLAVE );
$i = 0;
$startId = 0;
if ( $this->noCount ) {
$numPages = '[unknown]';
} else {
$numPages = $dbr->selectField( 'blob_tracking',
'COUNT(DISTINCT bt_page)',
# A condition is required so that this query uses the index
array( 'bt_moved' => 0 ),
__METHOD__
);
}
if ( $this->copyOnly ) {
$this->info( "Copying pages..." );
} else {
$this->info( "Moving pages..." );
}
while ( true ) {
$res = $dbr->select( 'blob_tracking',
array( 'bt_page' ),
array(
'bt_moved' => 0,
'bt_page > ' . $dbr->addQuotes( $startId )
),
__METHOD__,
array(
'DISTINCT',
'ORDER BY' => 'bt_page',
'LIMIT' => $this->batchSize,
)
);
if ( !$res->numRows() ) {
break;
}
foreach ( $res as $row ) {
$this->dispatch( 'doPage', $row->bt_page );
$i++;
}
$startId = $row->bt_page;
$this->report( 'pages', $i, $numPages );
}
$this->report( 'pages', $i, $numPages );
if ( $this->copyOnly ) {
$this->info( "All page copies queued." );
} else {
$this->info( "All page moves queued." );
}
}
/**
* Display a progress report
* @param string $label
* @param int $current
* @param int $end
*/
function report( $label, $current, $end ) {
$this->numBatches++;
if ( $current == $end || $this->numBatches >= $this->reportingInterval ) {
$this->numBatches = 0;
$this->info( "$label: $current / $end" );
$this->waitForSlaves();
}
}
/**
* Move all orphan text to the new clusters
*/
function doAllOrphans() {
$dbr = wfGetDB( DB_SLAVE );
$startId = 0;
$i = 0;
if ( $this->noCount ) {
$numOrphans = '[unknown]';
} else {
$numOrphans = $dbr->selectField( 'blob_tracking',
'COUNT(DISTINCT bt_text_id)',
array( 'bt_moved' => 0, 'bt_page' => 0 ),
__METHOD__ );
if ( !$numOrphans ) {
return;
}
}
if ( $this->copyOnly ) {
$this->info( "Copying orphans..." );
} else {
$this->info( "Moving orphans..." );
}
while ( true ) {
$res = $dbr->select( 'blob_tracking',
array( 'bt_text_id' ),
array(
'bt_moved' => 0,
'bt_page' => 0,
'bt_text_id > ' . $dbr->addQuotes( $startId )
),
__METHOD__,
array(
'DISTINCT',
'ORDER BY' => 'bt_text_id',
'LIMIT' => $this->batchSize
)
);
if ( !$res->numRows() ) {
break;
}
$ids = array();
foreach ( $res as $row ) {
$ids[] = $row->bt_text_id;
$i++;
}
// Need to send enough orphan IDs to the child at a time to fill a blob,
// so orphanBatchSize needs to be at least ~100.
// batchSize can be smaller or larger.
while ( count( $ids ) > $this->orphanBatchSize ) {
$args = array_slice( $ids, 0, $this->orphanBatchSize );
$ids = array_slice( $ids, $this->orphanBatchSize );
array_unshift( $args, 'doOrphanList' );
call_user_func_array( array( $this, 'dispatch' ), $args );
}
if ( count( $ids ) ) {
$args = $ids;
array_unshift( $args, 'doOrphanList' );
call_user_func_array( array( $this, 'dispatch' ), $args );
}
$startId = $row->bt_text_id;
$this->report( 'orphans', $i, $numOrphans );
}
$this->report( 'orphans', $i, $numOrphans );
$this->info( "All orphans queued." );
}
/**
* Main entry point for worker processes
*/
function executeChild() {
$this->debug( 'starting' );
$this->syncDBs();
while ( !feof( STDIN ) ) {
$line = rtrim( fgets( STDIN ) );
if ( $line == '' ) {
continue;
}
$this->debug( $line );
$args = explode( ' ', $line );
$cmd = array_shift( $args );
switch ( $cmd ) {
case 'doPage':
$this->doPage( intval( $args[0] ) );
break;
case 'doOrphanList':
$this->doOrphanList( array_map( 'intval', $args ) );
break;
case 'quit':
return;
}
$this->waitForSlaves();
}
}
/**
* Move tracked text in a given page
*
* @param int $pageId
*/
function doPage( $pageId ) {
$title = Title::newFromID( $pageId );
if ( $title ) {
$titleText = $title->getPrefixedText();
} else {
$titleText = '[deleted]';
}
$dbr = wfGetDB( DB_SLAVE );
// Finish any incomplete transactions
if ( !$this->copyOnly ) {
$this->finishIncompleteMoves( array( 'bt_page' => $pageId ) );
$this->syncDBs();
}
$startId = 0;
$trx = new CgzCopyTransaction( $this, $this->pageBlobClass );
while ( true ) {
$res = $dbr->select(
array( 'blob_tracking', 'text' ),
'*',
array(
'bt_page' => $pageId,
'bt_text_id > ' . $dbr->addQuotes( $startId ),
'bt_moved' => 0,
'bt_new_url IS NULL',
'bt_text_id=old_id',
),
__METHOD__,
array(
'ORDER BY' => 'bt_text_id',
'LIMIT' => $this->batchSize
)
);
if ( !$res->numRows() ) {
break;
}
$lastTextId = 0;
foreach ( $res as $row ) {
if ( $lastTextId == $row->bt_text_id ) {
// Duplicate (null edit)
continue;
}
$lastTextId = $row->bt_text_id;
// Load the text
$text = Revision::getRevisionText( $row );
if ( $text === false ) {
$this->critical( "Error loading {$row->bt_rev_id}/{$row->bt_text_id}" );
continue;
}
// Queue it
if ( !$trx->addItem( $text, $row->bt_text_id ) ) {
$this->debug( "$titleText: committing blob with " . $trx->getSize() . " items" );
$trx->commit();
$trx = new CgzCopyTransaction( $this, $this->pageBlobClass );
$this->waitForSlaves();
}
}
$startId = $row->bt_text_id;
}
$this->debug( "$titleText: committing blob with " . $trx->getSize() . " items" );
$trx->commit();
}
/**
* Atomic move operation.
*
* Write the new URL to the text table and set the bt_moved flag.
*
* This is done in a single transaction to provide restartable behavior
* without data loss.
*
* The transaction is kept short to reduce locking.
*
* @param int $textId
* @param string $url
*/
function moveTextRow( $textId, $url ) {
if ( $this->copyOnly ) {
$this->critical( "Internal error: can't call moveTextRow() in --copy-only mode" );
exit( 1 );
}
$dbw = wfGetDB( DB_MASTER );
$dbw->begin( __METHOD__ );
$dbw->update( 'text',
array( // set
'old_text' => $url,
'old_flags' => 'external,utf-8',
),
array( // where
'old_id' => $textId
),
__METHOD__
);
$dbw->update( 'blob_tracking',
array( 'bt_moved' => 1 ),
array( 'bt_text_id' => $textId ),
__METHOD__
);
$dbw->commit( __METHOD__ );
}
/**
* Moves are done in two phases: bt_new_url and then bt_moved.
* - bt_new_url indicates that the text has been copied to the new cluster.
* - bt_moved indicates that the text table has been updated.
*
* This function completes any moves that only have done bt_new_url. This
* can happen when the script is interrupted, or when --copy-only is used.
*
* @param array $conds
*/
function finishIncompleteMoves( $conds ) {
$dbr = wfGetDB( DB_SLAVE );
$startId = 0;
$conds = array_merge( $conds, array(
'bt_moved' => 0,
'bt_new_url IS NOT NULL'
) );
while ( true ) {
$res = $dbr->select( 'blob_tracking',
'*',
array_merge( $conds, array( 'bt_text_id > ' . $dbr->addQuotes( $startId ) ) ),
__METHOD__,
array(
'ORDER BY' => 'bt_text_id',
'LIMIT' => $this->batchSize,
)
);
if ( !$res->numRows() ) {
break;
}
$this->debug( 'Incomplete: ' . $res->numRows() . ' rows' );
foreach ( $res as $row ) {
$this->moveTextRow( $row->bt_text_id, $row->bt_new_url );
if ( $row->bt_text_id % 10 == 0 ) {
$this->waitForSlaves();
}
}
$startId = $row->bt_text_id;
}
}
/**
* Returns the name of the next target cluster
* @return string
*/
function getTargetCluster() {
$cluster = next( $this->destClusters );
if ( $cluster === false ) {
$cluster = reset( $this->destClusters );
}
return $cluster;
}
/**
* Gets a DB master connection for the given external cluster name
* @param string $cluster
* @return DatabaseBase
*/
function getExtDB( $cluster ) {
$lb = wfGetLBFactory()->getExternalLB( $cluster );
return $lb->getConnection( DB_MASTER );
}
/**
* Move an orphan text_id to the new cluster
*
* @param array $textIds
*/
function doOrphanList( $textIds ) {
// Finish incomplete moves
if ( !$this->copyOnly ) {
$this->finishIncompleteMoves( array( 'bt_text_id' => $textIds ) );
$this->syncDBs();
}
$trx = new CgzCopyTransaction( $this, $this->orphanBlobClass );
$res = wfGetDB( DB_SLAVE )->select(
array( 'text', 'blob_tracking' ),
array( 'old_id', 'old_text', 'old_flags' ),
array(
'old_id' => $textIds,
'bt_text_id=old_id',
'bt_moved' => 0,
),
__METHOD__,
array( 'DISTINCT' )
);
foreach ( $res as $row ) {
$text = Revision::getRevisionText( $row );
if ( $text === false ) {
$this->critical( "Error: cannot load revision text for old_id={$row->old_id}" );
continue;
}
if ( !$trx->addItem( $text, $row->old_id ) ) {
$this->debug( "[orphan]: committing blob with " . $trx->getSize() . " rows" );
$trx->commit();
$trx = new CgzCopyTransaction( $this, $this->orphanBlobClass );
$this->waitForSlaves();
}
}
$this->debug( "[orphan]: committing blob with " . $trx->getSize() . " rows" );
$trx->commit();
}
/**
* Wait for slaves (quietly)
*/
function waitForSlaves() {
$lb = wfGetLB();
while ( true ) {
list( $host, $maxLag ) = $lb->getMaxLag();
if ( $maxLag < 2 ) {
break;
}
sleep( 5 );
}
}
}
/**
* Class to represent a recompression operation for a single CGZ blob
*/
class CgzCopyTransaction {
public $parent;
public $blobClass;
public $cgz;
public $referrers;
/**
* Create a transaction from a RecompressTracked object
* @param RecompressTracked $parent
* @param string $blobClass
*/
function __construct( $parent, $blobClass ) {
$this->blobClass = $blobClass;
$this->cgz = false;
$this->texts = array();
$this->parent = $parent;
}
/**
* Add text.
* Returns false if it's ready to commit.
* @param string $text
* @param int $textId
* @return bool
*/
function addItem( $text, $textId ) {
if ( !$this->cgz ) {
$class = $this->blobClass;
$this->cgz = new $class;
}
$hash = $this->cgz->addItem( $text );
$this->referrers[$textId] = $hash;
$this->texts[$textId] = $text;
return $this->cgz->isHappy();
}
function getSize() {
return count( $this->texts );
}
/**
* Recompress text after some aberrant modification
*/
function recompress() {
$class = $this->blobClass;
$this->cgz = new $class;
$this->referrers = array();
foreach ( $this->texts as $textId => $text ) {
$hash = $this->cgz->addItem( $text );
$this->referrers[$textId] = $hash;
}
}
/**
* Commit the blob.
* Does nothing if no text items have been added.
* May skip the move if --copy-only is set.
*/
function commit() {
$originalCount = count( $this->texts );
if ( !$originalCount ) {
return;
}
// Check to see if the target text_ids have been moved already.
//
// We originally read from the slave, so this can happen when a single
// text_id is shared between multiple pages. It's rare, but possible
// if a delete/move/undelete cycle splits up a null edit.
//
// We do a locking read to prevent closer-run race conditions.
$dbw = wfGetDB( DB_MASTER );
$dbw->begin( __METHOD__ );
$res = $dbw->select( 'blob_tracking',
array( 'bt_text_id', 'bt_moved' ),
array( 'bt_text_id' => array_keys( $this->referrers ) ),
__METHOD__, array( 'FOR UPDATE' ) );
$dirty = false;
foreach ( $res as $row ) {
if ( $row->bt_moved ) {
# This row has already been moved, remove it
$this->parent->debug( "TRX: conflict detected in old_id={$row->bt_text_id}" );
unset( $this->texts[$row->bt_text_id] );
$dirty = true;
}
}
// Recompress the blob if necessary
if ( $dirty ) {
if ( !count( $this->texts ) ) {
// All have been moved already
if ( $originalCount > 1 ) {
// This is suspcious, make noise
$this->critical( "Warning: concurrent operation detected, are there two conflicting " .
"processes running, doing the same job?" );
}
return;
}
$this->recompress();
}
// Insert the data into the destination cluster
$targetCluster = $this->parent->getTargetCluster();
$store = $this->parent->store;
$targetDB = $store->getMaster( $targetCluster );
$targetDB->clearFlag( DBO_TRX ); // we manage the transactions
$targetDB->begin( __METHOD__ );
$baseUrl = $this->parent->store->store( $targetCluster, serialize( $this->cgz ) );
// Write the new URLs to the blob_tracking table
foreach ( $this->referrers as $textId => $hash ) {
$url = $baseUrl . '/' . $hash;
$dbw->update( 'blob_tracking',
array( 'bt_new_url' => $url ),
array(
'bt_text_id' => $textId,
'bt_moved' => 0, # Check for concurrent conflicting update
),
__METHOD__
);
}
$targetDB->commit( __METHOD__ );
// Critical section here: interruption at this point causes blob duplication
// Reversing the order of the commits would cause data loss instead
$dbw->commit( __METHOD__ );
// Write the new URLs to the text table and set the moved flag
if ( !$this->parent->copyOnly ) {
foreach ( $this->referrers as $textId => $hash ) {
$url = $baseUrl . '/' . $hash;
$this->parent->moveTextRow( $textId, $url );
}
}
}
}
Zerion Mini Shell 1.0