[imp] my experience

[Jose R. Roca]

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.

Cheers to all...

--
Jose.



On 12/20/05, Kevin M. Myer <kevin_myer at iu13.org> wrote:
>
> Quoting Jie Gao <J.Gao at isu.usyd.edu.au>:
>
> > Hi All
> >
> > I'd like to share some of my experience upgrading to:
> >
> > horde-3.0.7 + imp-h3-4.0.3.
> >
> > I, and my users, liked the new features, but I immediately ran into a
> > huge performance problem. I immediately moved the Mysql server to a
> > separate machine, an Opteron dual-core 2-CPU HP machine with 8GB of
> > memory.  And it still could not handle the load the mysql server put on
> > it, with up to 80% of CPU hogged up by the mysql server. The system
> > became unusable with over 100 or so users.
> >
> > We have found the following sql query to seem to be the main culprit:
> >
> > SELECT c.datatree_id, c.datatree_name FROM horde_datatree c LEFT JOIN
> > horde_datatree_attributes a1 ON
> > a1.datatree_id = c.datatree_id
> > WHERE c.group_uid = 'horde.shares.nag' AND ((a1.attribute_name =
> > 'owner' AND a1.attribute_value =
> > 'xxx at imap.xxx.xxx.xxx') OR (
> > a1.attribute_name = 'perm_users' AND a1.attribute_key =
> > 'xxx at imap.xxx.xxx.xxx' AND a1.attribute_value
> > & 8) OR (a1.attribute_nam
> > e = 'perm_creator' AND a1.attribute_value & 8) OR (a1.attribute_name
> > = 'perm_default' AND
> > a1.attribute_value & 8))   GROUP BY c.data
> > tree_id, c.datatree_name, c.datatree_order ORDER BY c.datatree_order,
> > c.datatree_name, c.datatree_id;
> >
> > It took 1min30sec to run this query with 200 concurrent users on the
> > system.
> >
> > We tried everything to tune the mysql server and gave it plenty of
> > connections, query cache, thread-cache, table cache, etc.  We even put
> > a partial index on the column attribute_value of the
> > horde_datatree_attributes table, which is a blob/text field.
> >
> > We have had to roll back and downgrade to an old verion of Hore/IMP.
> >
> > I hope this will serve as a warning to those people who are thinking of
> > upgrading. I didn't think I had one myself.
>
> Horde 3.1 will have some improvements in place to help performance.  A
> big one is gained by splitting the History out of the Datatree and into
> its own separate table.  See http://bugs.horde.org/ticket/?id=2298
>
> Kevin
>
> --
> Kevin M. Myer
> Senior Systems Administrator
> Lancaster-Lebanon Intermediate Unit 13  http://www.iu13.org
>
>
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