[horde] slow/no response when memcache is down

[Michael M Slusarz]

Quoting Chuck Hagenbuch <chuck at horde.org>:

> Quoting Matus UHLAR - fantomas <uhlar at fantomas.sk>:
>
>>> Quoting Matus UHLAR - fantomas <uhlar at fantomas.sk>:
>>>> I have configured horde to store sessions in mysql but use memcached.
>>>> I thought memcache will be used as cache and if the server is not  
>>>> reachable,
>>>> mysql will always be used.
>>>> However, when I turn memcached off, connection start hanging.
>>
>> On 05.04.11 10:35, Chuck Hagenbuch wrote:
>>> What do you mean by hanging? Do you know what's being blocked on?
>>
>> oh, sorry for using such weak explanation.
>>
>> Connecting to webmail and loading the login page was slow. I actually didn't
>> wait how long will it take - waiting 30 seconds is unacceptable for me.
>>
>> When I started up memcached, there was no problem.
>>
>> I checked up if it's not the firewall with DROP setting, it was not.
>>
>> Any idea what can that be?
>
> Naive explanation is that Horde is hanging while trying to connect  
> to the memcache server instead of realizing immediately that it's  
> down. Which memcache interface/client are you using?

We don't use memcache's timeout parameter when defining servers, which  
according to the PHP documentation is 1 second.

But 30 second delay sounds more like a socket connection timeout.  So  
this may not be the same thing.  And if it is a socket connection  
timeout, who knows if it is something PHP allows us to control.

michael

___________________________________
Michael Slusarz [slusarz at horde.org]