(PECL memcached >= 2.0.0)
Memcached::getAllKeys — Gets the keys stored on all the servers
Memcached::getAllKeys() queries each memcache server and retrieves an array of all keys stored on them at that point in time. This is not an atomic operation, so it isn't a truly consistent snapshot of the keys at point in time. As memcache doesn't guarantee to return all keys you also cannot assume that all keys have been returned.
注意:
This method is intended for debugging purposes and should not be used at scale!
此函数没有参数。
Returns the keys stored on all the servers on success 或者在失败时返回 false.