Please note that after flushing, you have to wait a certain amount of time (in my case < 1s) to be able to write to Memcached again. If you don't, Memcached::set() will return 1, although your data is in fact not saved.
(PECL memcache >= 1.0.0)
Memcache::flush -- memcache_flush — 清洗（删除）已经存储的所有的元素
Memcache::flush() 会立即使所有已经存在的元素失效。Memcache::flush() 实际上不会释放任何资源，而是将所有元素标记为已过期，已占用的内存会在新元素存储时覆盖。
此函数没有参数。
示例 #1 Memcache::flush()示例
<?php
/* procedural API */
$memcache_obj = memcache_connect('memcache_host', 11211);
memcache_flush($memcache_obj);
/* OO API */
$memcache_obj = new Memcache;
$memcache_obj->connect('memcache_host', 11211);
$memcache_obj->flush();
?>Please note that after flushing, you have to wait a certain amount of time (in my case < 1s) to be able to write to Memcached again. If you don't, Memcached::set() will return 1, although your data is in fact not saved.From the memcached mailing list:
"The flush has a one second granularity. The flush will expire all items up to the ones set within the same second."
It is imperative to wait at least one second after flush() command before further actions like repopulating the cache. Ohterwise new items < 1 second after flush() would be invalidatet instantaneous.
Example:
<?php
$memcache->flush();
$time = time()+1; //one second future
while(time() < $time) {
//sleep
}
$memcache->set('key', 'value'); // repopulate the cache
?>