Actually, the application status shows in YARN web UI is not determined by the jobmanager process exit code. Instead, we use "resourceManagerClient.unregisterApplicationMaster" to control the final status of YARN application. So although jobmanager exit with zero code, it still could show failed status in YARN web UI.
I have created a ticket to track this improvement[1]. [1]. https://issues.apache.org/jira/browse/FLINK-18828 Best, Yang Till Rohrmann <trohrm...@apache.org> 于2020年8月5日周三 下午3:56写道： > 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 >>>>>>>>> >>>>>>>>
