(PECL memcached >= 0.1.0)
Memcached::replaceByKey — Replace the item under an existing key on a specific server
Memcached::replaceByKey() is functionally equivalent to Memcached::replace(), except that the free-form server_key can be used to map the key to a specific server. This is useful if you need to keep a bunch of related keys on a certain server.
The key identifying the server to store the value on.
The key under which to store the value.
The value to store.
The expiration time, defaults to 0. See Expiration Times for more info.
Returns TRUE on success or FALSE on failure. The Memcached::getResultCode() will return Memcached::RES_NOTSTORED if the key does not exist.