PHP LoadBalancer::getAnyOpenConnection方法代码示例

 public function getLagTimes($serverIndexes, $wiki)
 {
     if (count($serverIndexes) == 1 && reset($serverIndexes) == 0) {
         // Single server only, just return zero without caching
         return array(0 => 0);
     }
     $expiry = 5;
     $requestRate = 10;
     $cache = $this->cache;
     $masterName = $this->parent->getServerName(0);
     $memcKey = wfMemcKey('lag_times', $masterName);
     $times = $cache->get($memcKey);
     if (is_array($times)) {
         # Randomly recache with probability rising over $expiry
         $elapsed = time() - $times['timestamp'];
         $chance = max(0, ($expiry - $elapsed) * $requestRate);
         if (mt_rand(0, $chance) != 0) {
             unset($times['timestamp']);
             // hide from caller
             return $times;
         }
         wfIncrStats('lag_cache.miss.expired');
     } else {
         wfIncrStats('lag_cache.miss.absent');
     }
     # Cache key missing or expired
     if ($cache->lock($memcKey, 0, 10)) {
         # Let this process alone update the cache value
         $unlocker = new ScopedCallback(function () use($cache, $memcKey) {
             $cache->unlock($memcKey);
         });
     } elseif (is_array($times)) {
         # Could not acquire lock but an old cache exists, so use it
         unset($times['timestamp']);
         // hide from caller
         return $times;
     }
     $times = array();
     foreach ($serverIndexes as $i) {
         if ($i == 0) {
             # Master
             $times[$i] = 0;
         } elseif (false !== ($conn = $this->parent->getAnyOpenConnection($i))) {
             $times[$i] = $conn->getLag();
         } elseif (false !== ($conn = $this->parent->openConnection($i, $wiki))) {
             $times[$i] = $conn->getLag();
             // 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
             // time cache miss cache, which is far less common that cache hits.
             $this->parent->closeConnection($conn);
         }
     }
     # Add a timestamp key so we know when it was cached
     $times['timestamp'] = time();
     $cache->set($memcKey, $times, $expiry + 10);
     unset($times['timestamp']);
     // hide from caller
     return $times;
 }

 public function getLagTimes($serverIndexes, $wiki)
 {
     if (count($serverIndexes) == 1 && reset($serverIndexes) == 0) {
         // Single server only, just return zero without caching
         return array(0 => 0);
     }
     $section = new ProfileSection(__METHOD__);
     $expiry = 5;
     $requestRate = 10;
     global $wgMemc;
     if (empty($wgMemc)) {
         $wgMemc = wfGetMainCache();
     }
     $masterName = $this->parent->getServerName(0);
     $memcKey = wfMemcKey('lag_times', $masterName);
     $times = $wgMemc->get($memcKey);
     if (is_array($times)) {
         # Randomly recache with probability rising over $expiry
         $elapsed = time() - $times['timestamp'];
         $chance = max(0, ($expiry - $elapsed) * $requestRate);
         if (mt_rand(0, $chance) != 0) {
             unset($times['timestamp']);
             // hide from caller
             return $times;
         }
         wfIncrStats('lag_cache_miss_expired');
     } else {
         wfIncrStats('lag_cache_miss_absent');
     }
     # Cache key missing or expired
     if ($wgMemc->add("{$memcKey}:lock", 1, 10)) {
         # Let this process alone update the cache value
         $unlocker = new ScopedCallback(function () use($wgMemc, $memcKey) {
             $wgMemc->delete($memcKey);
         });
     } elseif (is_array($times)) {
         # Could not acquire lock but an old cache exists, so use it
         unset($times['timestamp']);
         // hide from caller
         return $times;
     }
     $times = array();
     foreach ($serverIndexes as $i) {
         if ($i == 0) {
             # Master
             $times[$i] = 0;
         } elseif (false !== ($conn = $this->parent->getAnyOpenConnection($i))) {
             $times[$i] = $conn->getLag();
         } elseif (false !== ($conn = $this->parent->openConnection($i, $wiki))) {
             $times[$i] = $conn->getLag();
         }
     }
     # Add a timestamp key so we know when it was cached
     $times['timestamp'] = time();
     $wgMemc->set($memcKey, $times, $expiry + 10);
     unset($times['timestamp']);
     // hide from caller
     return $times;
 }

 /**
  * @param $serverIndexes
  * @param $wiki
  * @return array
  */
 function getLagTimes($serverIndexes, $wiki)
 {
     if (count($serverIndexes) == 1 && reset($serverIndexes) == 0) {
         // Single server only, just return zero without caching
         return array(0 => 0);
     }
     wfProfileIn(__METHOD__);
     $expiry = 5;
     $requestRate = 10;
     global $wgMemc;
     if (empty($wgMemc)) {
         $wgMemc = wfGetMainCache();
     }
     $masterName = $this->parent->getServerName(0);
     $memcKey = wfMemcKey('lag_times', $masterName);
     $times = $wgMemc->get($memcKey);
     if ($times) {
         # Randomly recache with probability rising over $expiry
         $elapsed = time() - $times['timestamp'];
         $chance = max(0, ($expiry - $elapsed) * $requestRate);
         if (mt_rand(0, $chance) != 0) {
             unset($times['timestamp']);
             wfProfileOut(__METHOD__);
             return $times;
         }
         wfIncrStats('lag_cache_miss_expired');
     } else {
         wfIncrStats('lag_cache_miss_absent');
     }
     # Cache key missing or expired
     $times = array();
     foreach ($serverIndexes as $i) {
         if ($i == 0) {
             # Master
             $times[$i] = 0;
         } elseif (false !== ($conn = $this->parent->getAnyOpenConnection($i))) {
             $times[$i] = $conn->getLag();
         } elseif (false !== ($conn = $this->parent->openConnection($i, $wiki))) {
             $times[$i] = $conn->getLag();
         }
     }
     # Add a timestamp key so we know when it was cached
     $times['timestamp'] = time();
     $wgMemc->set($memcKey, $times, $expiry);
     # But don't give the timestamp to the caller
     unset($times['timestamp']);
     $lagTimes = $times;
     wfProfileOut(__METHOD__);
     return $lagTimes;
 }

 /**
  * Notify the ChronologyProtector that the LoadBalancer is about to shut
  * down. Saves replication positions.
  *
  * @param LoadBalancer $lb
  * @return void
  */
 public function shutdownLB(LoadBalancer $lb)
 {
     if (session_id() == '' || $lb->getServerCount() <= 1) {
         return;
         // don't start a session; don't bother with non-replicated setups
     }
     $masterName = $lb->getServerName(0);
     if (isset($this->shutdownPositions[$masterName])) {
         return;
         // already done
     }
     // Only save the position if writes have been done on the connection
     $db = $lb->getAnyOpenConnection(0);
     $info = $lb->parentInfo();
     if (!$db || !$db->doneWrites()) {
         wfDebug(__METHOD__ . ": LB {$info['id']}, no writes done\n");
         return;
     }
     $pos = $db->getMasterPos();
     wfDebug(__METHOD__ . ": LB {$info['id']} has master pos {$pos}\n");
     $this->shutdownPositions[$masterName] = $pos;
 }

 /**
  * Notify the ChronologyProtector that the LoadBalancer is about to shut
  * down. Saves replication positions.
  *
  * @param LoadBalancer $lb
  * @return void
  */
 public function shutdownLB(LoadBalancer $lb)
 {
     if (!$this->enabled || $lb->getServerCount() <= 1) {
         return;
         // non-replicated setup or disabled
     }
     $info = $lb->parentInfo();
     $masterName = $lb->getServerName($lb->getWriterIndex());
     // Only save the position if writes have been done on the connection
     $db = $lb->getAnyOpenConnection($lb->getWriterIndex());
     if (!$db || !$db->doneWrites()) {
         wfDebugLog('replication', __METHOD__ . ": LB {$info['id']}, no writes done\n");
         return;
         // nothing to do
     }
     $pos = $db->getMasterPos();
     wfDebugLog('replication', __METHOD__ . ": LB {$info['id']} has master pos {$pos}\n");
     $this->shutdownPositions[$masterName] = $pos;
 }

 public function getLagTimes($serverIndexes, $wiki)
 {
     if (count($serverIndexes) == 1 && reset($serverIndexes) == 0) {
         # Single server only, just return zero without caching
         return array(0 => 0);
     }
     $key = $this->getLagTimeCacheKey();
     # Randomize TTLs to reduce stampedes (4.0 - 5.0 sec)
     $ttl = mt_rand(4000000.0, 5000000.0) / 1000000.0;
     # Keep keys around longer as fallbacks
     $staleTTL = 60;
     # (a) Check the local APC cache
     $value = $this->srvCache->get($key);
     if ($value && $value['timestamp'] > microtime(true) - $ttl) {
         wfDebugLog('replication', __METHOD__ . ": got lag times ({$key}) from local cache");
         return $value['lagTimes'];
         // cache hit
     }
     $staleValue = $value ?: false;
     # (b) Check the shared cache and backfill APC
     $value = $this->mainCache->get($key);
     if ($value && $value['timestamp'] > microtime(true) - $ttl) {
         $this->srvCache->set($key, $value, $staleTTL);
         wfDebugLog('replication', __METHOD__ . ": got lag times ({$key}) from main cache");
         return $value['lagTimes'];
         // cache hit
     }
     $staleValue = $value ?: $staleValue;
     # (c) Cache key missing or expired; regenerate and backfill
     if ($this->mainCache->lock($key, 0, 10)) {
         # Let this process alone update the cache value
         $cache = $this->mainCache;
         /** @noinspection PhpUnusedLocalVariableInspection */
         $unlocker = new ScopedCallback(function () use($cache, $key) {
             $cache->unlock($key);
         });
     } elseif ($staleValue) {
         # Could not acquire lock but an old cache exists, so use it
         return $staleValue['lagTimes'];
     }
     $lagTimes = array();
     foreach ($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();
             # 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
             # time cache miss cache, which is far less common that cache hits.
             $this->parent->closeConnection($conn);
         }
     }
     # Add a timestamp key so we know when it was cached
     $value = array('lagTimes' => $lagTimes, 'timestamp' => microtime(true));
     $this->mainCache->set($key, $value, $staleTTL);
     $this->srvCache->set($key, $value, $staleTTL);
     wfDebugLog('replication', __METHOD__ . ": re-calculated lag times ({$key})");
     return $value['lagTimes'];
 }