Archive for May, 2012

Weird Jenkins Error: java.lang.NoClassDefFoundError: hudson/model/ComputerSet

Wednesday, May 30th, 2012

I finally got passed that Jenkins NoClassDefFound error when managing nodes… Now no such errors and the system was back. The slave machines are back to work and projects are building now!

The Jenkins error message (the log jenkins.log is under /var/log/jenkins/ in a standard standalone Linux installation) does not make sense and was misleading:

May 29, 2012 3:03:32 PM hudson.triggers.SafeTimerTask run

SEVERE: Timer task hudson.model.LoadStatistics$LoadStatisticsUpdater@12c8855 failed

java.lang.NoClassDefFoundError: hudson/model/ComputerSet

at hudson.model.LoadStatistics$LoadStatisticsUpdater.doRun(


at java.util.TimerThread.mainLoop(

The class was there. We just need to remove nodeMonitor.xml when migrating Jenkins instance.

nodeMonitors.xml: when migrating to another instance of Jenkins, remove the old nodeMonitors.xml to solve that NoClassDefFound erroe/issue as follows:

sudo  mv /var/lib/jenkins/nodeMonitors.xml /var/lib/jenkins/nodeMonitors.xml.old

nodeMonitors.xml will be automatically generated.

During the time I tried to resolve the issue, I also tweaked the JDK setting in Jenkins config. I added a jdk named jdk1.6-/usr/java/default/bin/java with JAVA_HOME: /usr/java/default

Be sure to take this out in Jenkins config if you are using slaves; it depends on slave machines env varianle JAVA_HOME. Adding this only confuses the salve machine as this overrides its local JAVA_HOME setting. If your master machine is Linux and your slave machine is Windows(like for building .net applications we we also are doing, in addition to Java jobs), this will definitely cause an error: incorrect JDK home.

Nashville: cenntenial park

Saturday, May 26th, 2012

Free wifi, since 2005, incredible.

Parthenon: no air conditioning on top floor. Only in top floor with all statue replicas is photo allowed

The restroom in first floor really stinks is closed

Tuesday, May 22nd, 2012

Here is what I got from google cache:

Why did we close the doors?

It’s simple. AMA still works. Google are targeting networks which confirms one thing. Networks work. And they work too well. But this targeting, it’s being done by manual intervention.

Our first priority, is to protect the network, and how that network works. We’ll improve how our system works. We’ll tighten our belts. We were the first, and we’ll likely be the last. But understand one thing.

If AMA does go the way of the dodo, we’ll man up and tell you. To any networks that are still running, grow some balls and be honest.

Recent Family Friendly Events in Atlanta

Thursday, May 17th, 2012
  • Greek Festival: May 18-20
  • Stars and Strikes: Register at to receive free 2 bowling passes a day for kids, every week

Recent shoppings

Saturday, May 12th, 2012

I bought a 10 feet hdmi cable, a ds game and a 32gb micro sd card from amazon. So far only got hdmi cable, it works great so far.

Also bought a generic tablet holder from eBay. It’ll be a while before I receive and try them out.