[Deploying Sakai] Sakai 2.9 performance issue

[David Horwitz]

Hi All,

We are/did experience a performance issue last week we would like to seek community input on.

Some back ground:

Kernel 1,3,x based (1.3.2 msub with KNL-1068<https://jira.sakaiproject.org/browse/KNL-1068> applied)
Java 1.6.0_30
mysql 5.1.68

Javaopts:

-server -d64 -Xms5000m -Xmx5000m -XX:MaxPermSize=640m -Dhttp.proxyHost=campusnet.uct.ac.za -Dhttp.proxyPort=8080 -XX:+UseConcMarkSweepGC -XX:+ExplicitGCInvokesConcurrent -XX:+CMSIncrementalMode -verbose:gc -XX:+PrintGCApplicationStoppedTime -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps -Duser.language=en -Duser.region=ZA -Djava.awt.headless=true -Dnetworkaddress.cache.ttl=60 -Dorg.apache.jasper.compiler.Parser.STRICT_QUOTE_ESCAPING=false -Dsun.lang.ClassLoader.allowArraySyntax=true -Dhttp.agent=Sakai -Djava.net.preferIPv6Addresses=false -Djava.net.preferIPv4Stack=true


Symptoms:
Randomly nodes enter a state where they become increasingly unresponsive due to longer and more frequent full GC operations. Until Friday we seemed to see this randomly with a higher incidence after the end of the lectures, during extensive online testing on Friday we experienced this across all nodes. It seems to be unrelated to the node running times as we have seen it on nodes that have been restarted in the last 24 hours as well as others that have been running for some time.

Any one seen similar issues? As a preventative we have upgraded to the latest 1.6 jdk (1.6.0_45) but are far from convinced this is the problem.


Thanks

David
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UNIVERSITY OF CAPE TOWN

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