Uploaded image for project: 'Jenkins'
  1. Jenkins
  2. JENKINS-26947

Maven job stuck when slave channel get disconnected

XMLWordPrintable

      I find a way to trigger a remoting problem using tcp fault injection with netem. I'm able to trigger this wait call at hudson.remoting.Request.call(Request.java:146):

      while(response==null && !channel.isInClosed())
        // I don't know exactly when this can happen, as pendingCalls are cleaned up by Channel,
        // but in production I've observed that in rare occasion it can block forever, even after a channel
        // is gone. So be defensive against that.
        wait(30*1000);
      

      When this wait is triggered, the running build is stuck and consumes a executor. It loops over and over on the wait.

      To reproduce, setup a SSH slave using the attached Dockerfile, and setup netem on the docker0 bridge like this:

      tc qdisc add dev docker0 root netem
      tc qdisc change dev docker0 root netem corrupt 1
      

      Testing requires to run the job one time before configuring netem, as netem settings are applied to all network streams, it could fail while downloading Maven dependencies. I just launched a Maven build of a example project to trigger the problem. It might be a Maven specific problem...

      To remove netem settings, just run tc qdisc del dev docker0 root.

      I've attached the Dockerfile, the command I used to launch it and a threaddump of a Jenkins stuck master.

        1. stacktrace.txt
          44 kB
        2. launch.sh
          0.0 kB
        3. Dockerfile
          0.4 kB

            Unassigned Unassigned
            ydubreuil Yoann Dubreuil
            Votes:
            0 Vote for this issue
            Watchers:
            6 Start watching this issue

              Created:
              Updated: