[Building Sakai] Severe DB Performance Issues for 2.9

[Sobieralski, Damian Michael]

Is this the right stat?



HardCache: count:10000 hits:42596 misses:11992 hit%:78


From: Sam Ottenhoff [mailto:ottenhoff at longsight.com]
Sent: Wednesday, September 04, 2013 11:56 AM
To: Sobieralski, Damian Michael
Cc: sakai-dev at collab.sakaiproject.org
Subject: Re: [Building Sakai] Severe DB Performance Issues for 2.9

If you're not running 2.9.2+ web tool, then SAK-23841 is not relevant.

Can you share your cache hit/missed stats from the Admin Workspace -> Memory tool?

On Wed, Sep 4, 2013 at 11:36 AM, Sobieralski, Damian Michael <dsobiera at indiana.edu<mailto:dsobiera at indiana.edu>> wrote:
IU is into the 2nd week of classes and yesterday we saw heavy CPU load on database which then backed up the app servers.   Our users experienced System latency which then resulted in a lot of errors and very frustrated users.     As traffic slowed, the system recovered.

We're running a base 2.9.0 with cherry picked enhancements and performance fixes.  We did apply KNL-1011.

What we are noticing is under average to high load the DB is running at 100%.  We are noticing a LOT of calls such as:

SELECT TOOL_ID,
   REGISTRATION,
   TITLE,
   LAYOUT_HINTS,
   PAGE_ORDER
FROM SAKAI_SITE_TOOL
WHERE PAGE_ID = :1
ORDER BY PAGE_ORDER ASC

And

SELECT NAME,
   VALUE
FROM SAKAI_SITE_PAGE_PROPERTY
WHERE ( PAGE_ID = :1 )

Pre 2.9 upgrade we only had one query that ran over a million times. Both of these had over 140 million executions.

Any ideas what might be causing this behavior?  And, more importantly, what can be done to reduce this? This is a SEVERE problem for us as yesterday our system basically grinded to a halt w/ the DB locked at 100%.

We did find this: https://jira.sakaiproject.org/browse/SAK-23841

But as far as I know we're not using XFrame.  But could this still be the issue?

Thanks.

---
Damian Sobieralski
Indiana University

_______________________________________________
sakai-dev mailing list
sakai-dev at collab.sakaiproject.org<mailto:sakai-dev at collab.sakaiproject.org>
http://collab.sakaiproject.org/mailman/listinfo/sakai-dev

TO UNSUBSCRIBE: send email to sakai-dev-unsubscribe at collab.sakaiproject.org<mailto:sakai-dev-unsubscribe at collab.sakaiproject.org> with a subject of "unsubscribe"

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://collab.sakaiproject.org/pipermail/sakai-dev/attachments/20130904/da2642f6/attachment.html