> Hi to all, > > First of all please accept my apologies if this question answered > before. > I've searched for a straight answer but I couldn't find one. Maybe I'm > not looking in the right place. > > So, I've started using the memcached for user sessions and I back it > up with a database storage (in case of a miss or a memcached failure > or other events). So far so good, I'm happy with the results, it > really improves the performance. > > But, having two or more memcached servers and two or more web servers > in a load balance, when a user logs out (basically it issues a delete > in the memcached), can memcached client (I'm using the PHP client) or > memcached server guarantee that the session (or any key for that > matter) will be deleted from all memcached pool? Or I have to do this > myself? > > Thank you, > Adrian
While not specifically talking about deletes, this talks about how queries address a pool of memcached servers generically: http://code.google.com/p/memcached/wiki/TutorialCachingStory The short answer is that keys only exist on one server, so the client directly adds or deletes the only key every time.