/**
  * {@inheritdoc}
  */
 protected function doGetStats()
 {
     $servers = $this->memcached->getStats();
     $data = array(Cache::STATS_HITS => 0, Cache::STATS_MISSES => 0, Cache::STATS_UPTIME => 0, Cache::STATS_MEMORY_USAGE => 0, Cache::STATS_MEMORY_AVAILIABLE => 0);
     foreach ($servers as $server) {
         $stats = $this->getServerStats($server);
         $data[Cache::STATS_HITS] += $stats[Cache::STATS_HITS];
         $data[Cache::STATS_MISSES] += $stats[Cache::STATS_MISSES];
         $data[Cache::STATS_MEMORY_USAGE] += $stats[Cache::STATS_MEMORY_USAGE];
         $data[Cache::STATS_MEMORY_AVAILIABLE] += $stats[Cache::STATS_MEMORY_AVAILIABLE];
         if ($data[Cache::STATS_UPTIME] < $stats[Cache::STATS_UPTIME]) {
             $data[Cache::STATS_UPTIME] = $stats[Cache::STATS_UPTIME];
         }
     }
     return $data;
 }