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Diffstat (limited to 'includes/objectcache/RedisBagOStuff.php')
-rw-r--r--includes/objectcache/RedisBagOStuff.php130
1 files changed, 70 insertions, 60 deletions
diff --git a/includes/objectcache/RedisBagOStuff.php b/includes/objectcache/RedisBagOStuff.php
index de3511df..7d9903fe 100644
--- a/includes/objectcache/RedisBagOStuff.php
+++ b/includes/objectcache/RedisBagOStuff.php
@@ -20,11 +20,18 @@
* @file
*/
+/**
+ * Redis-based caching module for redis server >= 2.6.12
+ *
+ * @note: avoid use of Redis::MULTI transactions for twemproxy support
+ */
class RedisBagOStuff extends BagOStuff {
/** @var RedisConnectionPool */
protected $redisPool;
/** @var array List of server names */
protected $servers;
+ /** @var array Map of (tag => server name) */
+ protected $serverTagMap;
/** @var bool */
protected $automaticFailover;
@@ -34,7 +41,8 @@ class RedisBagOStuff extends BagOStuff {
* - servers: An array of server names. A server name may be a hostname,
* a hostname/port combination or the absolute path of a UNIX socket.
* If a hostname is specified but no port, the standard port number
- * 6379 will be used. Required.
+ * 6379 will be used. Arrays keys can be used to specify the tag to
+ * hash on in place of the host/port. Required.
*
* - connectTimeout: The timeout for new connections, in seconds. Optional,
* default is 1 second.
@@ -66,6 +74,10 @@ class RedisBagOStuff extends BagOStuff {
$this->redisPool = RedisConnectionPool::singleton( $redisConf );
$this->servers = $params['servers'];
+ foreach ( $this->servers as $key => $server ) {
+ $this->serverTagMap[is_int( $key ) ? $server : $key] = $server;
+ }
+
if ( isset( $params['automaticFailover'] ) ) {
$this->automaticFailover = $params['automaticFailover'];
} else {
@@ -73,8 +85,7 @@ class RedisBagOStuff extends BagOStuff {
}
}
- public function get( $key, &$casToken = null ) {
-
+ public function get( $key, &$casToken = null, $flags = 0 ) {
list( $server, $conn ) = $this->getConnection( $key );
if ( !$conn ) {
return false;
@@ -93,7 +104,6 @@ class RedisBagOStuff extends BagOStuff {
}
public function set( $key, $value, $expiry = 0 ) {
-
list( $server, $conn ) = $this->getConnection( $key );
if ( !$conn ) {
return false;
@@ -115,41 +125,7 @@ class RedisBagOStuff extends BagOStuff {
return $result;
}
- protected function cas( $casToken, $key, $value, $expiry = 0 ) {
-
- list( $server, $conn ) = $this->getConnection( $key );
- if ( !$conn ) {
- return false;
- }
- $expiry = $this->convertToRelative( $expiry );
- try {
- $conn->watch( $key );
-
- if ( $this->serialize( $this->get( $key ) ) !== $casToken ) {
- $conn->unwatch();
- return false;
- }
-
- // multi()/exec() will fail atomically if the key changed since watch()
- $conn->multi();
- if ( $expiry ) {
- $conn->setex( $key, $expiry, $this->serialize( $value ) );
- } else {
- // No expiry, that is very different from zero expiry in Redis
- $conn->set( $key, $this->serialize( $value ) );
- }
- $result = ( $conn->exec() == array( true ) );
- } catch ( RedisException $e ) {
- $result = false;
- $this->handleException( $conn, $e );
- }
-
- $this->logRequest( 'cas', $key, $server, $result );
- return $result;
- }
-
public function delete( $key ) {
-
list( $server, $conn ) = $this->getConnection( $key );
if ( !$conn ) {
return false;
@@ -167,8 +143,7 @@ class RedisBagOStuff extends BagOStuff {
return $result;
}
- public function getMulti( array $keys ) {
-
+ public function getMulti( array $keys, $flags = 0 ) {
$batches = array();
$conns = array();
foreach ( $keys as $key ) {
@@ -213,7 +188,6 @@ class RedisBagOStuff extends BagOStuff {
* @return bool
*/
public function setMulti( array $data, $expiry = 0 ) {
-
$batches = array();
$conns = array();
foreach ( $data as $key => $value ) {
@@ -257,10 +231,7 @@ class RedisBagOStuff extends BagOStuff {
return $result;
}
-
-
public function add( $key, $value, $expiry = 0 ) {
-
list( $server, $conn ) = $this->getConnection( $key );
if ( !$conn ) {
return false;
@@ -268,10 +239,11 @@ class RedisBagOStuff extends BagOStuff {
$expiry = $this->convertToRelative( $expiry );
try {
if ( $expiry ) {
- $conn->multi();
- $conn->setnx( $key, $this->serialize( $value ) );
- $conn->expire( $key, $expiry );
- $result = ( $conn->exec() == array( true, true ) );
+ $result = $conn->set(
+ $key,
+ $this->serialize( $value ),
+ array( 'nx', 'ex' => $expiry )
+ );
} else {
$result = $conn->setnx( $key, $this->serialize( $value ) );
}
@@ -297,7 +269,6 @@ class RedisBagOStuff extends BagOStuff {
* @return int|bool New value or false on failure
*/
public function incr( $key, $value = 1 ) {
-
list( $server, $conn ) = $this->getConnection( $key );
if ( !$conn ) {
return false;
@@ -306,6 +277,7 @@ class RedisBagOStuff extends BagOStuff {
return null;
}
try {
+ // @FIXME: on races, the key may have a 0 TTL
$result = $conn->incrBy( $key, $value );
} catch ( RedisException $e ) {
$result = false;
@@ -316,12 +288,12 @@ class RedisBagOStuff extends BagOStuff {
return $result;
}
- public function merge( $key, $callback, $exptime = 0, $attempts = 10 ) {
- if ( !is_callable( $callback ) ) {
- throw new Exception( "Got invalid callback." );
+ public function modifySimpleRelayEvent( array $event ) {
+ if ( array_key_exists( 'val', $event ) ) {
+ $event['val'] = serialize( $event['val'] ); // this class uses PHP serialization
}
- return $this->mergeViaCas( $key, $callback, $exptime, $attempts );
+ return $event;
}
/**
@@ -348,27 +320,65 @@ class RedisBagOStuff extends BagOStuff {
* @return array (server, RedisConnRef) or (false, false)
*/
protected function getConnection( $key ) {
- if ( count( $this->servers ) === 1 ) {
- $candidates = $this->servers;
- } else {
- $candidates = $this->servers;
+ $candidates = array_keys( $this->serverTagMap );
+
+ if ( count( $this->servers ) > 1 ) {
ArrayUtils::consistentHashSort( $candidates, $key, '/' );
if ( !$this->automaticFailover ) {
$candidates = array_slice( $candidates, 0, 1 );
}
}
- foreach ( $candidates as $server ) {
+ while ( ( $tag = array_shift( $candidates ) ) !== null ) {
+ $server = $this->serverTagMap[$tag];
$conn = $this->redisPool->getConnection( $server );
- if ( $conn ) {
- return array( $server, $conn );
+ if ( !$conn ) {
+ continue;
}
+
+ // If automatic failover is enabled, check that the server's link
+ // to its master (if any) is up -- but only if there are other
+ // viable candidates left to consider. Also, getMasterLinkStatus()
+ // does not work with twemproxy, though $candidates will be empty
+ // by now in such cases.
+ if ( $this->automaticFailover && $candidates ) {
+ try {
+ if ( $this->getMasterLinkStatus( $conn ) === 'down' ) {
+ // If the master cannot be reached, fail-over to the next server.
+ // If masters are in data-center A, and slaves in data-center B,
+ // this helps avoid the case were fail-over happens in A but not
+ // to the corresponding server in B (e.g. read/write mismatch).
+ continue;
+ }
+ } catch ( RedisException $e ) {
+ // Server is not accepting commands
+ $this->handleException( $conn, $e );
+ continue;
+ }
+ }
+
+ return array( $server, $conn );
}
+
$this->setLastError( BagOStuff::ERR_UNREACHABLE );
+
return array( false, false );
}
/**
+ * Check the master link status of a Redis server that is configured as a slave.
+ * @param RedisConnRef $conn
+ * @return string|null Master link status (either 'up' or 'down'), or null
+ * if the server is not a slave.
+ */
+ protected function getMasterLinkStatus( RedisConnRef $conn ) {
+ $info = $conn->info();
+ return isset( $info['master_link_status'] )
+ ? $info['master_link_status']
+ : null;
+ }
+
+ /**
* Log a fatal error
* @param string $msg
*/
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-10 13:12:49 +0000