memory leak in Build Pipeline plugin (BuildForm)

(This issue was likely also reported on Google Code by someone else but never answered.)

We're suffering from a severe memory leak that seems to be coming from the Build Pipeline plugin, growing with each HTTP request for the build pipeline view.

Analysis

We took a heap dump after just one work day of run-time and ran jhat on it. The graph shows memory usage growing almost linearly over the course of a day and the heap analysis shows an unusually high number of instances of the class au.com.centrumsystems.hudson.plugin.buildpipeline.BuildForm.

Instance Counts for All Classes (excluding platform)

806069 instances of class org.kohsuke.stapler.bind.BoundObjectTable$1 
800273 instances of class au.com.centrumsystems.hudson.plugin.buildpipeline.BuildForm 
800273 instances of class au.com.centrumsystems.hudson.plugin.buildpipeline.PipelineBuild 
51265 instances of class hudson.util.CopyOnWriteList 
31526 instances of class hudson.util.DescribableList 
30784 instances of class [Lorg.apache.commons.jexl.parser.Node; 
24643 instances of class jenkins.model.lazy.BuildReference 
24228 instances of class net.bull.javamelody.CounterRequest 
22565 instances of class com.thoughtworks.xstream.core.util.ConcurrentWeakHashMap$HashEntry 
22565 instances of class com.thoughtworks.xstream.core.util.ConcurrentWeakHashMap$WeakKeyReference 
18441 instances of class hudson.model.View$PropertyList 

Workaround

• In issue 143 on Google Code, the reporter also mentioned that they downgraded the plugin to version "1.2.3".
• We were restarting Jenkins every night, which caused other problems.
• For now, we're able to free up memory by identifying the session that keeps refreshing the pipeline view and killing that session.