Failure with libmemcached

[Kevin Dalley]

After some investigation, I found out that the problem was due to a
couple of libmemcached bugs, for which I have submitted patches.

There is still a question of how to handle out of sync problems.  It may
show up again, and recovering nicely, with minimal confusion, would be
wonderful.


On Fri, 2008-01-25 at 09:32 -0800, Kevin Dalley wrote:
> I have looked at a series of memcached_set, memcached_get,
> memcached_delete, memcached_flush.  I'm getting strange return values,
> followed by a client stuck in a poll.
> 
> 
> Everything goes quite well for a while.  Then the return codes get
> strange, with memcached_set returning NOT_FOUND, memcached_get returning
> stored.  Other strange errors, and eventually the client is stuck in a
> poll.
> 
> I assume that the client and server disagree about their position.  Once
> they get lost, things get worse over time.
> 
> This is on a FreeBSD4.11 box, with a 1.2.4 server, and a new version of
> libmemcached, pulled down yesterday.  A few weeks old version also shows
> this problem.  What should I do?  Perhaps I should should repeat the
> request. Perhaps I should shut down and reopen the connection.  If it
> doesn't happen often, I may try this.  Perhaps I should try to
> understand the problem more completely.
> 
> Here are a few odd returns which I see.
> 
> Then things get stranger.  memcached_get returns MEMCACHED_STORED.  In
> fact, it returns quite a few of them.
> 
> Eventually memcached_set returns a few MEMCACHED_SERVER_END, mingled in
> with the MEMCACHED_STORED.
> 
> memcached_set returns NOT_FOUND.
> 
> memcached_get returns SERVER DELETE
> 
> memcached_set returns SERVER_END
> 
> memcached_set returns NOT_FOUND