[horde] Sessions consuming CPU

[Simon Wilson]

----- Message from lst_hoe02 at kwsoft.de ---------
    Date: Fri, 04 Nov 2011 10:56:00 +0100
    From: lst_hoe02 at kwsoft.de
Subject: Re: [horde] Sessions consuming CPU
      To: horde at lists.horde.org


> Zitat von Simon Wilson <simon at simonandkate.net>:
>
>>
>>
>> Simon Wilson
>> M: 0400 12 11 16
>>
>> On 04/11/2011, at 5:51 PM, LALOT Dominique <dom.lalot at gmail.com> wrote:
>>
>>> 2011/11/4 Simon Wilson <simon at simonandkate.net>
>>> Over the last few weeks I have noticed periods of time where the  
>>> virtual server running Horde climbs to 100% CPU utilisation. This  
>>> can last for hours.
>>>
>>> Last time was 6 days ago, but then it did it again at 00:41am this  
>>> morning, so I jumped into some troubleshooting.
>>>
>>> Stop httpd and the CPU drops to 0. Start it again, and within a  
>>> minute or two it hits 100% again, and stays there.
>>>
>>> So I emptied the logs, stopped httpd, and set to monitoring it.
>>>
>>> iPhones / iPads turned off, Imp logged out.
>>> Started httpd.
>>> httpd access_log for Horde remains empty, with ZERO incoming requests.
>>> After about 15 seconds this time - httpd hits 100%. AT THE SAME  
>>> TIME, this message hits the horde log:
>>>
>>> 2011-11-04T01:04:11+10:00 ERR: HORDE [imp] Server does not support  
>>> TLS connections. [pid 22050 on line 340 of  
>>> "/var/www/horde4/imp/lib/Imap.php"]
>>>
>>> This message hits /var/log/horde up to 25 times per second, during  
>>> which CPU usage remains at 100%.
>>>
>>> Still no incoming requests for httpd in httpd/access_log, or  
>>> errors in httpd/error_log.
>>>
>>> The exact second that Horde logs that error, CPU hits 100%. Stop  
>>> httpd, restart it, reproduce it. Did this several times over an  
>>> hour, producing the exact same result - still ZERO http requests  
>>> made of horde, 100% CPU at the same point the error gets logged.
>>>
>>> So I logged in to Horde, and looked in "Sessions". About 30  
>>> sessions sitting in there, dating back up to a week old, across  
>>> iPhone, Ipad, Mozilla, IE.
>>>
>>> As soon as I deleted the session files from /var/lib/php/session  
>>> (kicked me out of Horde as expected), CPU usage immediately  
>>> dropped, and the IMAP TLS message stopped.
>>>
>>> It hasn't done it this morning since, and clearing the old  
>>> sessions has stopped both the errors in the log and brought CPU  
>>> usage down to about 3%.
>>>
>>> Is there any way I can stop this reoccurring (other than  
>>> monitoring for 100% CPU load and triggering a session file delete!)
>>>
>>> Thanks
>>> Simon.
>>>
>>> --
>>> Simon Wilson
>>> M: 0400 12 11 16
>>>
>>> --
>>> Horde mailing list
>>> Frequently Asked Questions: http://horde.org/faq/
>>> To unsubscribe, mail: horde-unsubscribe at lists.horde.org
>>>
>>> There was a bug in imp 5.0.13. For some search, IE9 is looping and  
>>> leads to 100% CPU. The new version 5.0.14 should be better. You  
>>> don't tell your version..
>>>
>>>
>>> --
>>> Dominique LALOT
>>> Ingénieur Systèmes et Réseaux
>>> http://annuaire.univmed.fr/showuser.php?uid=lalot
>>
>> Thanks Dom.
>>
>> Fully current and updated as at yesterday evening so not that tho.
>
> That might be your problem. Have a look at imp/config/backends.php,  
> the first entry is ENABLED by default and uses TLS. I have not yet  
> figured out for which updates it overides backends.php but it might  
> be considered as a bug.
>
> Regards
>
> Andreas

My backends.local.php overrides that default imap entry with my IMAP  
server details, and it works fine - with TLS. TLS is fully functional  
with no issues across the entire setup.

Simon.