Hi Ron, Isn't the cluster (session or per job) only using the execution.attached to determine whether the client is attached? If so, the client can always include the information of whether it's an attached client or not in the JobSubmissoinRequestBody, right? For a shared session cluster, there could be multiple clients submitting jobs to it. These clients may or may not be attached. A static execution.attached configuration for the session cluster does not work in this case, right?
The current problem of execution.attached is that it is not always honored. For example, if a session cluster was started with execution.attached set to false. And a client submits a job later to that session cluster with execution.attached set to true. In this case, the cluster won't (and shouldn't) shutdown after the job finishes or the attached client loses connection. So, in fact, the execution.attached configuration is only honored by the client, but not the cluster. Therefore, I think removing it makes sense. Thanks, Jiangjie (Becket) Qin On Thu, Aug 17, 2023 at 12:31 AM liu ron <ron9....@gmail.com> wrote: > Hi, Jiangjie > > Sorry for late reply. Thank you for such a detailed response. As you say, > there are three behaviours here for users and I agree with you. The goal of > this FLIP is to clarify the behaviour of the client side, which I also > agree with. However, as weihua said, the config execution.attached is not > only for per-job mode, but also for session mode, but the FLIP says that > this is only for per-job mode, and this config will be removed in the > future because the per-job mode has been deprecated. I don't think this is > correct and we should change the description in the corresponding section > of the FLIP. Since execution.attached is used in session mode, there is a > compatibility issue here if we change it directly to > client.attached.after.submission, and I think we should make this clear in > the FLIP. > > Best, > Ron > > Becket Qin <becket....@gmail.com> 于2023年8月14日周一 20:33写道： > > > Hi Ron and Weihua, > > > > Thanks for the feedback. > > > > There seem three user sensible behaviors that we are talking about: > > > > 1. The behavior on the client side, i.e. whether blocking until the job > > finishes or not. > > > > 2. The behavior of the submitted job, whether stop the job execution if > the > > client is detached from the Flink cluster, i.e. whether bind the > lifecycle > > of the job with the connection status of the attached client. For > example, > > one might want to keep a batch job running until finish even after the > > client connection is lost. But it makes sense to stop the job upon client > > connection lost if the job invokes collect() on a streaming job. > > > > 3. The behavior of the Flink cluster (JM and TMs), whether shutdown the > > Flink cluster if the client is detached from the Flink cluster, i.e. > > whether bind the cluster lifecycle with the job lifecycle. For dedicated > > clusters (application cluster or dedicated session clusters), the > lifecycle > > of the cluster should be bound with the job lifecycle. But for shared > > session clusters, the lifecycle of the Flink cluster should be > independent > > of the jobs running in it. > > > > As we can see, these three behaviors are sort of independent, the current > > configurations fail to support all the combination of wanted behaviors. > > Ideally there should be three separate configurations, for example: > > - client.attached.after.submission and client.heartbeat.timeout control > the > > behavior on the client side. > > - jobmanager.cancel-on-attached-client-exit controls the behavior of the > > job when an attached client lost connection. The client heartbeat timeout > > and attach-ness will be also passed to the JM upon job submission. > > - cluster.shutdown-on-first-job-finishes *(*or > > jobmanager.shutdown-cluster-after-job-finishes) controls the cluster > > behavior after the job finishes normally / abnormally. This is a cluster > > level setting instead of a job level setting. Therefore it can only be > set > > when launching the cluster. > > > > The current code sort of combines config 2 and 3 into > > execution.shutdown-on-attach-exit. > > This assumes the the life cycle of the cluster is the same as the job > when > > the client is attached. This FLIP does not intend to change that. but > using > > the execution.attached config for the client behavior control looks > > misleading. So this FLIP proposes to replace it with a more intuitive > > config of client.attached.after.submission. This makes it clear that it > is > > a configuration controlling the client side behavior, instead of the > > execution of the job. > > > > Thanks, > > > > Jiangjie (Becket) Qin > > > > > > > > > > > > On Thu, Aug 10, 2023 at 10:34 PM Weihua Hu <huweihua....@gmail.com> > wrote: > > > > > Hi Allison > > > > > > Thanks for driving this FLIP. It's a valuable feature for batch jobs. > > > This helps keep "Drop Per-Job Mode [1]" going. > > > > > > +1 for this proposal. > > > > > > However, it seems that the change in this FLIP is not detailed enough. > > > I have a few questions. > > > > > > 1. The config 'execution.attached' is not only used in per-job mode, > > > but also in session mode to shutdown the cluster. IMHO, it's better to > > > keep this option name. > > > > > > 2. This FLIP only mentions YARN mode. I believe this feature should > > > work in both YARN and Kubernetes mode. > > > > > > 3. Within the attach mode, we support two features: > > > execution.shutdown-on-attached-exit > > > and client.heartbeat.timeout. These should also be taken into account. > > > > > > 4. The Application Mode will shut down once the job has been completed. > > > So, if we use the flink client to poll job status via REST API for > attach > > > mode, > > > there is a chance that the client will not be able to retrieve the job > > > finish status. > > > Perhaps FLINK-24113[3] will help with this. > > > > > > > > > [1]https://issues.apache.org/jira/browse/FLINK-26000 > > > [2] > > > > > > > > > https://nightlies.apache.org/flink/flink-docs-master/docs/deployment/resource-providers/native_kubernetes/#session-mode > > > [2]https://issues.apache.org/jira/browse/FLINK-24113 > > > > > > Best, > > > Weihua > > > > > > > > > On Thu, Aug 10, 2023 at 10:47 AM liu ron <ron9....@gmail.com> wrote: > > > > > > > Hi, Allison > > > > > > > > Thanks for driving this proposal, it looks cool for batch jobs under > > > > application mode. But after reading your FLIP document and [1], I > have > > a > > > > question. Why do you want to rename the execution.attached > > configuration > > > to > > > > client.attached.after.submission and at the same time deprecate > > > > execution.attached? Based on your design, I understand the role of > > these > > > > two options are the same. Introducing a new option would increase the > > > cost > > > > of understanding and use for the user, so why not follow the idea > > > discussed > > > > in FLINK-25495 and make Application mode support attached.execution. > > > > > > > > [1] https://issues.apache.org/jira/browse/FLINK-25495 > > > > > > > > Best, > > > > Ron > > > > > > > > Venkatakrishnan Sowrirajan <vsowr...@asu.edu> 于2023年8月9日周三 02:07写道： > > > > > > > > > This is definitely a useful feature especially for the flink batch > > > > > execution workloads using flow orchestrators like Airflow, Azkaban, > > > Oozie > > > > > etc. Thanks for reviving this issue and starting a FLIP. > > > > > > > > > > Regards > > > > > Venkata krishnan > > > > > > > > > > > > > > > On Mon, Aug 7, 2023 at 4:09 PM Allison Chang > > > > <alch...@linkedin.com.invalid > > > > > > > > > > > wrote: > > > > > > > > > > > Hi all, > > > > > > > > > > > > I am opening this thread to discuss this proposal to support > > attached > > > > > > execution on Flink Application Completion for Batch Jobs. The > link > > to > > > > the > > > > > > FLIP proposal is here: > > > > > > > > > > > > > > > > > > > > > https://urldefense.com/v3/__https://cwiki.apache.org/confluence/display/FLINK/FLIP-323*3A*Support*Attached*Execution*on*Flink*Application*Completion*for*Batch*Jobs__;JSsrKysrKysrKys!!IKRxdwAv5BmarQ!friFO6bJub5FKSLhPIzA6kv-7uffv-zXlv9ZLMKqj_xMcmZl62HhsgvwDXSCS5hfSeyHZgoAVSFg3fk7ChaAFNKi$ > > > > > > > > > > > > This FLIP proposes adding back attached execution for Application > > > Mode. > > > > > In > > > > > > the past attached execution was supported for the per-job mode, > > which > > > > > will > > > > > > be deprecated and we want to include this feature back into > > > Application > > > > > > mode. > > > > > > > > > > > > Please reply to this email thread and share your > thoughts/opinions. > > > > > > > > > > > > Thank you! > > > > > > > > > > > > Allison Chang > > > > > > > > > > > > > > > > > > > > >
