[horde] webmail session problems, help required...

[Jan Schneider]

Zitat von Kostas Katsamakas <kmak at ccf.auth.gr>:

>
>
> Jan Schneider wrote:
>> Zitat von Kostas Katsamakas <kmak at ccf.auth.gr>:
>>
>>> Hello to everyone.
>>>
>>> Recently our horde/imp email has been upgraded and we are facing  
>>> some problems regarding
>>> our sessions.
>>>
>>> We are curently using
>>> horde 3.3.6
>>> imp H3 4.3.4
>>>
>>> We get a lot of log messages:
>>>
>>> [horde] Error retrieving session data (id =  
>>> 7331c3f467119efaa34fcdb38464a629): Lock wait timeout exceeded; try  
>>> restarting transaction [pid 25439 on line 144 of  
>>> "/var/www/mydomain/htdocs/horde/lib/Horde/SessionHandler/mysql.php"]
>>>
>>> and some
>>>
>>> [horde] Error writing session data: Lock wait timeout exceeded;  
>>> try restarting transaction [pid 25440 on line 185 of  
>>> "/var/www/mydomain/htdocs/horde/lib/Horde/SessionHandler/mysql.php"]
>>>
>>> these problems appear really often when i set in horde config:
>>> $conf[sessionhandler][params][persistent] = true
>>
>> Then don't enable it. Unless you have a bottleneck in  
>> authenticating database users or making database connections, it  
>> won't help you much anyway.
>>
> Yes, for the moment we keep the persistent connection disabled.
>>> Note: I use Mysql based sessions and  
>>> $conf[sessionhandler][params][rowlocking] = true;
>>
>> And do you use the InnoDB engine for the session handler table?
>>
> Yes horde_sessionhandler table is InnoDB , all other tables are  
> MyISAM in the database.

This shouldn't happen then, because we only lock rows in this case,  
i.e. a single session. So this could only happen if users have two  
requests running at the same time, and the locking timeout is too short.
Parallel requests can happen through sidebar reloading, portal block  
reloading, ajax requests etc. Your locking timeout should be at least  
as long as your server needs to answer a common request.

Jan.

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