[Deploying Sakai] database load

Berg, Alan A.M.Berg at uva.nl
Thu Dec 2 03:39:25 PST 2010

Hi all,

Chris Kretler is the QA lead for performance for 2.8.  The Columbia QA server is under constant low level load and the results are going to be regularly analyzed.  If anyone wishes to preemptively involve themselves in the 2.8 QA cycle please make contact.

Chuck, have you got any usage stats. For example, if you add a valve in the tomcat server.xml you can get response times. 

 <Valve className="org.apache.catalina.valves.AccessLogValve"
                    pattern='%h %l %u %t "%r" %s %b "%{User-Agent}i" %T'
                    prefix="localhost_access_log." resolveHosts="false" suffix=".txt"/>

I would advise looking at the slower tools to begin with, the MySQL slow  query logs and the cache hit rates. Please Jira any defects found.

Alan Berg
QA Director - The Sakai Foundation

Senior Developer / Quality Assurance
Group Education and Research Services
Central Computer Services
University of Amsterdam


From: production-bounces at collab.sakaiproject.org [production-bounces at collab.sakaiproject.org] on behalf of Charles Hedrick [hedrick at rutgers.edu]
Sent: 01 December 2010 21:15
To: sakai
Subject: [Deploying Sakai] database load

I've had a feeling that database load was heavier for 2.7 than 2.6. I finally put together a script to clarify it. If you look at https://sakai.rutgers.edu/stats/max.txt, you'll see for each day values 1, 6 and 11 for that day, when the values are sorted largest first. The numbers are CPU% on our database system. Our usage is going up slighly, but not enough to explain what looks like a factor of 2 increase. We can survive that, but we can't survive another increase like this.

Note that we changed not only from 2.6 to 2.7 but from Mysql 4.1 to 5.1. It's possible that it's mysql more than Sakai that is the issue. Our mysql is CPU limited. There's very little I/O.

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