Jenkins + Play 1.2.4 : problems with cobertura lock files / report

Clearly this is due JVM locking issues either in your JVM implementation, or rather, in the way you are deploying your cobertura JAR.

Jenkins can spawn up alot of JVM threads, and if cobetura is on your global classpath, its possible that some weird collisions are happening.

I assume, ultimately, that this should be attributed to a minor bug in cobertura (unless the complex corbertura file locking is solving some other more important problem).

According to the source code for Cobertura's FileLock (cobertura/src/main/java/net/sourceforge/cobertura/util/FileLocker.java), there are some issues around multiple JVM's loading up the Cobertura jar.

To solve, make sure there is only one copy and one app launching and using Corbetura.

The reason your VM implementation fixed it, most likely, is that you've decreased the amount of variability in the way cobetrura can be loaded. Also maybe you are restarting your VM with higher frequency then your jenkins server.

In our jenkins corbertura builds, we just use the maven plugin and this seems to work fine without issue (but then again, we are not using java 1.7, nor are we using Play).

This has been bothering us for a while (play 1.2.4/Jenkins). There is some problem due to overlapping sequences between jenkins cobertura plugin (report publish) and play framework cobertura module. I believe its purely timing coincidence and hence intermittent. We have the following work around for the lack of a better resolution.

Removed jenkins cobertura report publish action from the main build job. We created a new jenkins job that is setup with publish cobertura coverage report action. In the new job, we have the shell action to copy the coverage.xml from the main build job workspace to the workspace of the new job for cobertura coverage report publish action to run. The copy (for obvious reasons) is done to avoid running both play cobertura and jenkins cobertura in the same job.

Its not the best but happy to see the coverage report/graphs :-)

The trick is to use one datafile (cobertura.ser) per module to avoid locks from parallel tasks.

With ant:

<cobertura-instrument todir="${build.dir}" datafile="cobertura.ser.${modulename}">    ...

At end merge the many cobertura files into one cobertura file:

<target name="merge-coverage">    <cobertura-merge datafile="cobertura.ser">        <fileset dir="${build.dir}">            <include name="cobertura.ser.*" />        </fileset>    </cobertura-merge></target>