Yes for the other deployments it is not a problem. A reason why people preferred non-zero exit codes in case of FAILED jobs is that this is easier to monitor than having to take a look at the actual job result. Moreover, in the YARN web UI the application shows as failed if I am not mistaken. However, from a framework's perspective, a FAILED job does not mean that Flink has failed and, hence, the return code could still be 0 in my opinion.
Cheers, Till On Wed, Aug 5, 2020 at 9:30 AM Yang Wang <danrtsey...@gmail.com> wrote: > Hi Eleanore, > > Yes, I suggest to use Job to replace Deployment. It could be used to run > jobmanager one time and finish after a successful/failed completion. > > However, using Job still could not solve your problem completely. Just as > Till said, When a job exhausts the restart strategy, the jobmanager > pod will terminate with non-zero exit code. It will cause the K8s > restarting it again. Even though we could set the resartPolicy and > backoffLimit, > this is not a clean and correct way to go. We should terminate the > jobmanager process with zero exit code in such situation. > > @Till Rohrmann <trohrm...@apache.org> I just have one concern. Is it a > special case for K8s deployment? For standalone/Yarn/Mesos, it seems that > terminating with > non-zero exit code is harmless. > > > Best, > Yang > > Eleanore Jin <eleanore....@gmail.com> 于2020年8月4日周二 下午11:54写道： > >> Hi Yang & Till, >> >> Thanks for your prompt reply! >> >> Yang, regarding your question, I am actually not using k8s job, as I put >> my app.jar and its dependencies under flink's lib directory. I have 1 k8s >> deployment for job manager, and 1 k8s deployment for task manager, and 1 >> k8s service for job manager. >> >> As you mentioned above, if flink job is marked as failed, it will cause >> the job manager pod to be restarted. Which is not the ideal behavior. >> >> Do you suggest that I should change the deployment strategy from using >> k8s deployment to k8s job? In case the flink program exit with non-zero >> code (e.g. exhausted number of configured restart), pod can be marked as >> complete hence not restarting the job again? >> >> Thanks a lot! >> Eleanore >> >> On Tue, Aug 4, 2020 at 2:49 AM Yang Wang <danrtsey...@gmail.com> wrote: >> >>> @Till Rohrmann <trohrm...@apache.org> In native mode, when a Flink >>> application terminates with FAILED state, all the resources will be cleaned >>> up. >>> >>> However, in standalone mode, I agree with you that we need to rethink >>> the exit code of Flink. When a job exhausts the restart >>> strategy, we should terminate the pod and do not restart again. After >>> googling, it seems that we could not specify the restartPolicy >>> based on exit code[1]. So maybe we need to return a zero exit code to >>> avoid restarting by K8s. >>> >>> [1]. >>> https://stackoverflow.com/questions/48797297/is-it-possible-to-define-restartpolicy-based-on-container-exit-code >>> >>> Best, >>> Yang >>> >>> Till Rohrmann <trohrm...@apache.org> 于2020年8月4日周二 下午3:48写道： >>> >>>> @Yang Wang <danrtsey...@gmail.com> I believe that we should >>>> rethink the exit codes of Flink. In general you want K8s to restart a >>>> failed Flink process. Hence, an application which terminates in state >>>> FAILED should not return a non-zero exit code because it is a valid >>>> termination state. >>>> >>>> Cheers, >>>> Till >>>> >>>> On Tue, Aug 4, 2020 at 8:55 AM Yang Wang <danrtsey...@gmail.com> wrote: >>>> >>>>> Hi Eleanore, >>>>> >>>>> I think you are using K8s resource "Job" to deploy the jobmanager. >>>>> Please set .spec.template.spec.restartPolicy = "Never" and >>>>> spec.backoffLimit = 0. >>>>> Refer here[1] for more information. >>>>> >>>>> Then, when the jobmanager failed because of any reason, the K8s job >>>>> will be marked failed. And K8s will not restart the job again. >>>>> >>>>> [1]. >>>>> https://kubernetes.io/docs/concepts/workloads/controllers/job/#job-termination-and-cleanup >>>>> >>>>> >>>>> Best, >>>>> Yang >>>>> >>>>> Eleanore Jin <eleanore....@gmail.com> 于2020年8月4日周二 上午12:05写道： >>>>> >>>>>> Hi Till, >>>>>> >>>>>> Thanks for the reply! >>>>>> >>>>>> I manually deploy as per-job mode [1] and I am using Flink 1.8.2. >>>>>> Specifically, I build a custom docker image, which I copied the app jar >>>>>> (not uber jar) and all its dependencies under /flink/lib. >>>>>> >>>>>> So my question is more like, in this case, if the job is marked as >>>>>> FAILED, which causes k8s to restart the pod, this seems not help at all, >>>>>> what are the suggestions for such scenario? >>>>>> >>>>>> Thanks a lot! >>>>>> Eleanore >>>>>> >>>>>> [1] >>>>>> https://ci.apache.org/projects/flink/flink-docs-release-1.8/ops/deployment/kubernetes.html#flink-job-cluster-on-kubernetes >>>>>> >>>>>> On Mon, Aug 3, 2020 at 2:13 AM Till Rohrmann <trohrm...@apache.org> >>>>>> wrote: >>>>>> >>>>>>> Hi Eleanore, >>>>>>> >>>>>>> how are you deploying Flink exactly? Are you using the application >>>>>>> mode with native K8s support to deploy a cluster [1] or are you manually >>>>>>> deploying a per-job mode [2]? >>>>>>> >>>>>>> I believe the problem might be that we terminate the Flink process >>>>>>> with a non-zero exit code if the job reaches the >>>>>>> ApplicationStatus.FAILED >>>>>>> [3]. >>>>>>> >>>>>>> cc Yang Wang have you observed a similar behavior when running Flink >>>>>>> in per-job mode on K8s? >>>>>>> >>>>>>> [1] >>>>>>> https://ci.apache.org/projects/flink/flink-docs-release-1.11/ops/deployment/native_kubernetes.html#flink-kubernetes-application >>>>>>> [2] >>>>>>> https://ci.apache.org/projects/flink/flink-docs-release-1.11/ops/deployment/kubernetes.html#job-cluster-resource-definitions >>>>>>> [3] >>>>>>> https://github.com/apache/flink/blob/master/flink-runtime/src/main/java/org/apache/flink/runtime/clusterframework/ApplicationStatus.java#L32 >>>>>>> >>>>>>> On Fri, Jul 31, 2020 at 6:26 PM Eleanore Jin <eleanore....@gmail.com> >>>>>>> wrote: >>>>>>> >>>>>>>> Hi Experts, >>>>>>>> >>>>>>>> I have a flink cluster (per job mode) running on kubernetes. The >>>>>>>> job is configured with restart strategy >>>>>>>> >>>>>>>> restart-strategy.fixed-delay.attempts: >>>>>>>> 3restart-strategy.fixed-delay.delay: 10 s >>>>>>>> >>>>>>>> >>>>>>>> So after 3 times retry, the job will be marked as FAILED, hence the >>>>>>>> pods are not running. However, kubernetes will then restart the job >>>>>>>> again >>>>>>>> as the available replicas do not match the desired one. >>>>>>>> >>>>>>>> I wonder what are the suggestions for such a scenario? How should I >>>>>>>> configure the flink job running on k8s? >>>>>>>> >>>>>>>> Thanks a lot! >>>>>>>> Eleanore >>>>>>>> >>>>>>>
