public function __construct( $parent ) {
$this->parent = $parent;
- $this->srvCache = ObjectCache::newAccelerator( 'hash' );
+ $this->srvCache = ObjectCache::getLocalServerInstance( 'hash' );
$this->mainCache = ObjectCache::getLocalClusterInstance();
}
public function getLagTimes( $serverIndexes, $wiki ) {
if ( count( $serverIndexes ) == 1 && reset( $serverIndexes ) == 0 ) {
# Single server only, just return zero without caching
- return array( 0 => 0 );
+ return [ 0 => 0 ];
}
$key = $this->getLagTimeCacheKey();
# (a) Check the local APC cache
$value = $this->srvCache->get( $key );
if ( $value && $value['timestamp'] > ( microtime( true ) - $ttl ) ) {
- wfDebugLog( 'replication', __FUNCTION__ . ": got lag times ($key) from local cache" );
+ wfDebugLog( 'replication', __METHOD__ . ": got lag times ($key) from local cache" );
return $value['lagTimes']; // cache hit
}
$staleValue = $value ?: false;
$value = $this->mainCache->get( $key );
if ( $value && $value['timestamp'] > ( microtime( true ) - $ttl ) ) {
$this->srvCache->set( $key, $value, $staleTTL );
- wfDebugLog( 'replication', __FUNCTION__ . ": got lag times ($key) from main cache" );
+ wfDebugLog( 'replication', __METHOD__ . ": got lag times ($key) from main cache" );
return $value['lagTimes']; // cache hit
}
return $staleValue['lagTimes'];
}
- $lagTimes = array();
+ $lagTimes = [];
foreach ( $serverIndexes as $i ) {
- if ( $i == 0 ) { # Master
- $lagTimes[$i] = 0;
- } elseif ( false !== ( $conn = $this->parent->getAnyOpenConnection( $i ) ) ) {
- $lagTimes[$i] = $conn->getLag();
- } elseif ( false !== ( $conn = $this->parent->openConnection( $i, $wiki ) ) ) {
- $lagTimes[$i] = $conn->getLag();
+ if ( $i == $this->parent->getWriterIndex() ) {
+ $lagTimes[$i] = 0; // master always has no lag
+ continue;
+ }
+
+ $conn = $this->parent->getAnyOpenConnection( $i );
+ if ( $conn ) {
+ $close = false; // already open
+ } else {
+ $conn = $this->parent->openConnection( $i, $wiki );
+ $close = true; // new connection
+ }
+
+ if ( !$conn ) {
+ $lagTimes[$i] = false;
+ $host = $this->parent->getServerName( $i );
+ wfDebugLog( 'replication', __METHOD__ . ": host $host (#$i) is unreachable" );
+ continue;
+ }
+
+ $lagTimes[$i] = $conn->getLag();
+ if ( $lagTimes[$i] === false ) {
+ $host = $this->parent->getServerName( $i );
+ wfDebugLog( 'replication', __METHOD__ . ": host $host (#$i) is not replicating?" );
+ }
+
+ if ( $close ) {
# Close the connection to avoid sleeper connections piling up.
# Note that the caller will pick one of these DBs and reconnect,
# which is slightly inefficient, but this only matters for the lag
}
# Add a timestamp key so we know when it was cached
- $value = array( 'lagTimes' => $lagTimes, 'timestamp' => microtime( true ) );
+ $value = [ 'lagTimes' => $lagTimes, 'timestamp' => microtime( true ) ];
$this->mainCache->set( $key, $value, $staleTTL );
$this->srvCache->set( $key, $value, $staleTTL );
- wfDebugLog( 'replication', __FUNCTION__ . ": re-calculated lag times ($key)" );
+ wfDebugLog( 'replication', __METHOD__ . ": re-calculated lag times ($key)" );
return $value['lagTimes'];
}
}
private function getLagTimeCacheKey() {
- # Lag is per-server, not per-DB, so key on the master DB name
- return wfGlobalCacheKey( 'lag-times', $this->parent->getServerName( 0 ) );
+ $writerIndex = $this->parent->getWriterIndex();
+ // Lag is per-server, not per-DB, so key on the master DB name
+ return $this->srvCache->makeGlobalKey(
+ 'lag-times', $this->parent->getServerName( $writerIndex )
+ );
}
}