(PECL memcached >= 2.0.0)
Memcached::deleteMultiByKey — Delete multiple items from a specific server
$server_key, array $keys, int $time = 0): bool
   Memcached::deleteMultiByKey() is functionally equivalent to
   Memcached::deleteMulti(), except that the free-form
   server_key can be used to map the
   keys to a specific server.
  
server_key本键名用于识别储存和读取值的服务器。没有将实际的键名散列到具体的项目,而是在决定与哪一个 memcached 服务器通信时将其散列为服务器键名。这使得关联的项目在单一的服务上被组合起来以提高多重操作的效率。
keysThe keys to be deleted.
timeThe amount of time the server will wait to delete the items.
   成功时返回 true, 或者在失败时返回 false。
   The Memcached::getResultCode() will return
   Memcached::RES_NOTFOUND if the key does not exist.