[imp] my experience

[Didi Rieder]

Quoting Didi Rieder <adrieder at sbox.tugraz.at>:

> Quoting "Jose R. Roca" <joseroca at gmail.com>:
>
>> I basically ran into the same problem and I did basically the same thing you
>> did, throw all the hardware I could find to the problem. Now, since my
>> instalation was a new one and my users only had access to IMP without any
>> other feature before hand, I just took out Nag which happens to be the
>> application that runs that query each time a user logs in. As soon as I took
>> Nag out everything ran smoothly. I dont know if you can make the same choice
>> that I did since you might already have users using the old Nag, but I can
>> say that it worked for me.
>>
>> Never acually tried seperating the history out of the Datatree might try
>> that out now and try using the Nag application soon.
>
> I can only confirm this!
> I'm running HEAD. But I also have huge mySQL performance problems as
> soon as "Nag" is enabled. So it seems that the splitting of the
> Datatree is not enough for a real speed up...
>
> ... at least not in an environment with more than several hundred
> concurrent users.
> And I can't believe that this is about hardware. We have 4 servers
> acting as webservers behind a loadbalancer equipped with a SSL
> crypto-card, and a separate 4 way 8GB system as mySQL server.
>
> I just wonder what "Nag" is doing. I already disabled the sharing
> options for "Turba", "Kronolith" and "Nag". But the only thing which
> helps to get the load from the mySQL server is to disable "Nag".

I think I found the reason for the performance drop down in my IMP config.
Some how I changed the option $conf['tasklist']['use_tasklist'] to  
true. Setting it back to false made the mySQL server calm down again.

Stupid me! The performance hit is also documented on the setup page:

    ----8<------8<------8<--------
    If you do not want this functionality enabled (it will add to server load
    because the list of available task categories must be generated on every
    page load), you should disable this checkbox
    ----8<------8<------8<--------

with $conf['tasklist']['use_tasklist'] set to false in the IMP config  
and "Nag" enabled in Horde registry, everything is fine now.

I hope this experience is also helpful for someone else.

Didi

-- 
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Didi Rieder
adrieder at sbox.tugraz.at
PGPKey ID: 3431D0B0
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