Tim Starling has submitted this change and it was merged.
Change subject: [LockManager] Added a RedisLockManager class.
......................................................................
[LockManager] Added a RedisLockManager class.
Change-Id: I7ade74eb307a5075533f36836768af60f106a6b9
---
M includes/AutoLoader.php
M includes/filebackend/lockmanager/LockManager.php
A includes/filebackend/lockmanager/RedisLockManager.php
3 files changed, 260 insertions(+), 4 deletions(-)
Approvals:
Tim Starling: Verified; Looks good to me, approved
diff --git a/includes/AutoLoader.php b/includes/AutoLoader.php
index 88bb21b..4a8ecaa 100644
--- a/includes/AutoLoader.php
+++ b/includes/AutoLoader.php
@@ -573,8 +573,9 @@
'LSLockManager' => 'includes/filebackend/lockmanager/LSLockManager.php',
'MemcLockManager' =>
'includes/filebackend/lockmanager/MemcLockManager.php',
'QuorumLockManager' =>
'includes/filebackend/lockmanager/QuorumLockManager.php',
- 'MySqlLockManager' =>
'includes/filebackend/lockmanager/DBLockManager.php',
- 'PostgreSqlLockManager' =>
'includes/filebackend/lockmanager/DBLockManager.php',
+ 'MySqlLockManager'=>
'includes/filebackend/lockmanager/DBLockManager.php',
+ 'PostgreSqlLockManager'=>
'includes/filebackend/lockmanager/DBLockManager.php',
+ 'RedisLockManager'=>
'includes/filebackend/lockmanager/RedisLockManager.php',
'NullLockManager' => 'includes/filebackend/lockmanager/LockManager.php',
'FileOp' => 'includes/filebackend/FileOp.php',
'FileOpBatch' => 'includes/filebackend/FileOpBatch.php',
diff --git a/includes/filebackend/lockmanager/LockManager.php
b/includes/filebackend/lockmanager/LockManager.php
index 9b7a7ff..9c778c7 100644
--- a/includes/filebackend/lockmanager/LockManager.php
+++ b/includes/filebackend/lockmanager/LockManager.php
@@ -151,7 +151,7 @@
*
* @param array $paths List of storage paths
* @param $type integer LockManager::LOCK_* constant
- * @return string
+ * @return Status
*/
abstract protected function doLock( array $paths, $type );
@@ -160,7 +160,7 @@
*
* @param array $paths List of storage paths
* @param $type integer LockManager::LOCK_* constant
- * @return string
+ * @return Status
*/
abstract protected function doUnlock( array $paths, $type );
}
diff --git a/includes/filebackend/lockmanager/RedisLockManager.php
b/includes/filebackend/lockmanager/RedisLockManager.php
new file mode 100644
index 0000000..e8e5996
--- /dev/null
+++ b/includes/filebackend/lockmanager/RedisLockManager.php
@@ -0,0 +1,255 @@
+<?php
+/**
+ * Version of LockManager based on using redis servers.
+ *
+ * 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 LockManager
+ */
+
+/**
+ * Manage locks using redis servers.
+ *
+ * Version of LockManager based on using redis servers.
+ * This is meant for multi-wiki systems that may share files.
+ * All locks are non-blocking, which avoids deadlocks.
+ *
+ * All lock requests for a resource, identified by a hash string, will map to
one
+ * bucket. Each bucket maps to one or several peer servers, each running redis.
+ * A majority of peers must agree for a lock to be acquired.
+ *
+ * This class requires Redis 2.6 as it makes use Lua scripts for fast atomic
operations.
+ *
+ * @ingroup LockManager
+ * @since 1.22
+ */
+class RedisLockManager extends QuorumLockManager {
+ /** @var Array Mapping of lock types to the type actually used */
+ protected $lockTypeMap = array(
+ self::LOCK_SH => self::LOCK_SH,
+ self::LOCK_UW => self::LOCK_SH,
+ self::LOCK_EX => self::LOCK_EX
+ );
+
+ /** @var RedisConnectionPool */
+ protected $redisPool;
+ /** @var Array Map server names to hostname/IP and port numbers */
+ protected $lockServers = array();
+
+ protected $session = ''; // string; random UUID
+
+ /**
+ * Construct a new instance from configuration.
+ *
+ * $config paramaters include:
+ * - lockServers : Associative array of server names to
"<IP>:<port>" strings.
+ * - srvsByBucket : Array of 1-16 consecutive integer keys, starting
from 0,
+ * each having an odd-numbered list of server names
(peers) as values.
+ * - redisConfig : Configuration for
RedisConnectionPool::__construct().
+ *
+ * @param Array $config
+ * @throws MWException
+ */
+ public function __construct( array $config ) {
+ parent::__construct( $config );
+
+ $this->lockServers = $config['lockServers'];
+ // Sanitize srvsByBucket config to prevent PHP errors
+ $this->srvsByBucket = array_filter( $config['srvsByBucket'],
'is_array' );
+ $this->srvsByBucket = array_values( $this->srvsByBucket ); //
consecutive
+
+ $config['redisConfig']['serializer'] = 'none';
+ $this->redisPool = RedisConnectionPool::singleton(
$config['redisConfig'] );
+
+ $this->session = wfRandomString( 32 );
+ }
+
+ protected function getLocksOnServer( $lockSrv, array $paths, $type ) {
+ $status = Status::newGood();
+
+ $server = $this->lockServers[$lockSrv];
+ $conn = $this->redisPool->getConnection( $server );
+ if ( !$conn ) {
+ foreach ( $paths as $path ) {
+ $status->fatal( 'lockmanager-fail-acquirelock',
$path );
+ }
+ return $status;
+ }
+
+ $keys = array_map( array( $this, 'recordKeyForPath' ), $paths
); // lock records
+
+ try {
+ static $script =
+<<<LUA
+ if ARGV[1] ~= 'EX' and ARGV[1] ~= 'SH' then
+ return redis.error_reply('Unrecognized lock
type given (must be EX or SH)')
+ end
+ local failed = {}
+ -- Check that all the locks can be acquired
+ for i,resourceKey in ipairs(KEYS) do
+ local keyIsFree = true
+ local currentLocks =
redis.call('hKeys',resourceKey)
+ for i,lockKey in ipairs(currentLocks) do
+ local _, _, type, session =
string.find(lockKey,"(%w+):(%w+)")
+ -- Check any locks that are not owned
by this session
+ if session ~= ARGV[2] then
+ local lockTimestamp =
redis.call('hGet',resourceKey,lockKey)
+ if 1*lockTimestamp < ( ARGV[4]
- ARGV[3] ) then
+ -- Lock is stale, so
just prune it out
+
redis.call('hDel',resourceKey,lockKey)
+ elseif ARGV[1] == 'EX' or type
== 'EX' then
+ keyIsFree = false
+ break
+ end
+ end
+ end
+ if not keyIsFree then
+ failed[#failed+1] = resourceKey
+ end
+ end
+ -- If all locks could be acquired, then do so
+ if #failed == 0 then
+ for i,resourceKey in ipairs(KEYS) do
+ redis.call('hSet',resourceKey,ARGV[1]
.. ':' .. ARGV[2],ARGV[4])
+ -- In addition to invalidation logic,
be sure to garbage collect
+ redis.call('expire',resourceKey,ARGV[3])
+ end
+ end
+ return failed
+LUA;
+ $res = $conn->luaEval( $script,
+ array_merge(
+ $keys, // KEYS[0], KEYS[1],...KEYS[N]
+ array(
+ $type === self::LOCK_SH ? 'SH'
: 'EX', // ARGV[1]
+ $this->session, // ARGV[2]
+ $this->lockTTL, // ARGV[3]
+ time() // ARGV[4]
+ )
+ ),
+ count( $keys ) # number of first argument(s)
that are keys
+ );
+ } catch ( RedisException $e ) {
+ $res = false;
+ $this->redisPool->handleException( $server, $conn, $e );
+ }
+
+ if ( $res === false ) {
+ foreach ( $paths as $path ) {
+ $status->fatal( 'lockmanager-fail-acquirelock',
$path );
+ }
+ } else {
+ $pathsByKey = array_combine( $keys, $paths );
+ foreach ( $res as $key ) {
+ $status->fatal( 'lockmanager-fail-acquirelock',
$pathsByKey[$key] );
+ }
+ }
+
+ return $status;
+ }
+
+ protected function freeLocksOnServer( $lockSrv, array $paths, $type ) {
+ $status = Status::newGood();
+
+ $server = $this->lockServers[$lockSrv];
+ $conn = $this->redisPool->getConnection( $server );
+ if ( !$conn ) {
+ foreach ( $paths as $path ) {
+ $status->fatal( 'lockmanager-fail-releaselock',
$path );
+ }
+ return $status;
+ }
+
+ $keys = array_map( array( $this, 'recordKeyForPath' ), $paths
); // lock records
+
+ try {
+ static $script =
+<<<LUA
+ if ARGV[1] ~= 'EX' and ARGV[1] ~= 'SH' then
+ return redis.error_reply('Unrecognized lock
type given (must be EX or SH)')
+ end
+ local failed = {}
+ for i,resourceKey in ipairs(KEYS) do
+ local released =
redis.call('hDel',resourceKey,ARGV[1] .. ':' .. ARGV[2])
+ if released > 0 then
+ -- Remove the whole structure if it is
now empty
+ if redis.call('hLen',resourceKey) == 0
then
+ redis.call('del',resourceKey)
+ end
+ else
+ failed[#failed+1] = resourceKey
+ end
+ end
+ return failed
+LUA;
+ $res = $conn->luaEval( $script,
+ array_merge(
+ $keys, // KEYS[0], KEYS[1],...KEYS[N]
+ array(
+ $type === self::LOCK_SH ? 'SH'
: 'EX', // ARGV[1]
+ $this->session // ARGV[2]
+ )
+ ),
+ count( $keys ) # number of first argument(s)
that are keys
+ );
+ } catch ( RedisException $e ) {
+ $res = false;
+ $this->redisPool->handleException( $server, $conn, $e );
+ }
+
+ if ( $res === false ) {
+ foreach ( $paths as $path ) {
+ $status->fatal( 'lockmanager-fail-releaselock',
$path );
+ }
+ } else {
+ $pathsByKey = array_combine( $keys, $paths );
+ foreach ( $res as $key ) {
+ $status->fatal( 'lockmanager-fail-releaselock',
$pathsByKey[$key] );
+ }
+ }
+
+ return $status;
+ }
+
+ protected function releaseAllLocks() {
+ return Status::newGood(); // not supported
+ }
+
+ protected function isServerUp( $lockSrv ) {
+ return (bool)$this->redisPool->getConnection(
$this->lockServers[$lockSrv] );
+ }
+
+ /**
+ * @param $path string
+ * @return string
+ */
+ protected function recordKeyForPath( $path ) {
+ return implode( ':', array( __CLASS__, 'locks',
$this->sha1Base36Absolute( $path ) ) );
+ }
+
+ /**
+ * Make sure remaining locks get cleared for sanity
+ */
+ function __destruct() {
+ while ( count( $this->locksHeld ) ) {
+ foreach ( $this->locksHeld as $path => $locks ) {
+ $this->doUnlock( array( $path ), self::LOCK_EX
);
+ $this->doUnlock( array( $path ), self::LOCK_SH
);
+ }
+ }
+ }
+}
--
To view, visit https://gerrit.wikimedia.org/r/49799
To unsubscribe, visit https://gerrit.wikimedia.org/r/settings
Gerrit-MessageType: merged
Gerrit-Change-Id: I7ade74eb307a5075533f36836768af60f106a6b9
Gerrit-PatchSet: 13
Gerrit-Project: mediawiki/core
Gerrit-Branch: master
Gerrit-Owner: Aaron Schulz <[email protected]>
Gerrit-Reviewer: Aaron Schulz <[email protected]>
Gerrit-Reviewer: Tim Starling <[email protected]>
Gerrit-Reviewer: jenkins-bot
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