@Gyula Thank you We will work on this and try to come up with an approach.
On Fri, Feb 17, 2023 at 6:12 PM Gyula Fóra <gyula.f...@gmail.com> wrote: > In case you guys feel strongly about this I suggest you try to fork the > autoscaler implementation and make a version that works with both the > Kubernetes operator and YARN. > If your solution is generic and works well, we can discuss the way forward. > > Unfortunately me or my team don't really have the resources to assist you > with the YARN effort as we are mostly invested in Kubernetes but of course > we are happy to review your work. > > Gyula > > > On Fri, Feb 17, 2023 at 1:09 PM Prabhu Joseph <prabhujose.ga...@gmail.com> > wrote: > > > @Gyula > > > > >> It is easier to make the operator work with jobs running in different > > types of clusters than to take the > > autoscaler module itself and plug that in somewhere else. > > > > Our (part of Samrat's team) main problem is to leverage the AutoScaler > > Recommendation Engine part of Flink-Kubernetes-Operator for our Flink > jobs > > running on YARN. > > Currently, it is not feasible as the autoscaler module is tightly coupled > > with the operator. We agree that the operator serves the two core > > requirements, but the operator itself > > cannot be used for Flink jobs running on YARN. Those core requirements > are > > solved through other mechanisms in the case of YARN. But the main problem > > for us is *how to* > > *use the AutoScaler Recommendation Engine for Flink Jobs on YARN.* > > > > > > > > > > > > > > > > > > On Fri, Feb 17, 2023 at 6:34 AM Shammon FY <zjur...@gmail.com> wrote: > > > > > Hi Gyula, Samrat > > > > > > Thanks for your input and I totally agree with you that it's really big > > > work. As @Samrat mentioned above, I think it's not a short way to make > > the > > > autoscaler completely independent too. But I still find some valuable > > > points for the `completely independent autoscaler`, and I think this > may > > be > > > the goal we need to achieve in the future. > > > > > > 1. A large k8s cluster may manage thousands of machines, and users may > > run > > > tens of thousands flink jobs in one k8s cluster. If the autoscaler > > manages > > > all these jobs, the autoscaler should be horizontal expansion. > > > > > > 2. As you mentioned, "execute the job stateful upgrades safely" is > > indeed a > > > complexity work, but I think we should decouple it from k8s operator > > > > > > a) In addition to k8s, there may be some other resource management > > > > > > b) Flink may support more scaler operations by REST API, such as > FLIP-291 > > > [1] > > > > > > c) In our production environment, there's a 'Job Submission Gateway' > > which > > > stores job info and config, monitors the status of running jobs. After > > the > > > autoscaler upgrades the job, it must update the config in Gateway and > > users > > > can restart his job with the updated config to avoid resource conflict. > > > Under these circumstances, the autoscaler sending upgrade requests to > the > > > gateway may be a good choice. > > > > > > > > > [1] > > > > > > > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-291%3A+Externalized+Declarative+Resource+Management > > > > > > > > > Best, > > > Shammon > > > > > > > > > On Thu, Feb 16, 2023 at 11:03 PM Gyula Fóra <gyula.f...@gmail.com> > > wrote: > > > > > > > @Shammon , Samrat: > > > > > > > > I appreciate the enthusiasm and I wish this was only a matter of > > > intention > > > > but making the autoscaler work without the operator may be a pretty > big > > > > task. > > > > You must not forget 2 core requirements here. > > > > > > > > 1. The autoscaler logic itself has to run somewhere (in this case on > > k8s > > > > within the operator)S > > > > 2. Something has to execute the job stateful upgrades safely based on > > the > > > > scaling decisions (in this case the operator does that). > > > > > > > > 1. Can be solved almost anywhere easily however you need resiliency > etc > > > for > > > > this to be a prod application, 2. is the really tricky part. The > > operator > > > > was actually built to execute job upgrades, if you look at the code > you > > > > will appreciate the complexity of the task. > > > > > > > > As I said in the earlier thread. It is easier to make the operator > work > > > > with jobs running in different types of clusters than to take the > > > > autoscaler module itself and plug that in somewhere else. > > > > > > > > Gyula > > > > > > > > > > > > On Thu, Feb 16, 2023 at 3:12 PM Samrat Deb <decordea...@gmail.com> > > > wrote: > > > > > > > > > Hi Shammon, > > > > > > > > > > Thank you for your input, completely aligned with you. > > > > > > > > > > We are fine with either of the options , > > > > > > > > > > but IMO, to start with it will be easy to have it in the > > > > > flink-kubernetes-operator as a module instead of a separate repo > > which > > > > > requires additional effort. > > > > > > > > > > Given that we would be incrementally working on making an > autoscaling > > > > > recommendation framework generic enough, > > > > > > > > > > Once it reaches a point where the community feels it needs to be > > moved > > > > to a > > > > > separate repo we can take a call. > > > > > > > > > > Bests, > > > > > > > > > > Samrat > > > > > > > > > > > > > > > On Thu, Feb 16, 2023 at 7:37 PM Samrat Deb <decordea...@gmail.com> > > > > wrote: > > > > > > > > > > > Hi Max , > > > > > > If you are fine and aligned with the same thought , since this is > > > going > > > > > to > > > > > > be very useful to us, we are ready to help / contribute > additional > > > work > > > > > > required. > > > > > > > > > > > > Bests, > > > > > > Samrat > > > > > > > > > > > > > > > > > > On Thu, 16 Feb 2023 at 5:28 PM, Shammon FY <zjur...@gmail.com> > > > wrote: > > > > > > > > > > > >> Hi Samrat > > > > > >> > > > > > >> Do you mean to create an independent module for flink scaling in > > > > > >> flink-k8s-operator? How about creating a project such as > > > > > >> `flink-auto-scaling` which is completely independent? Besides > > > resource > > > > > >> managers such as k8s and yarn, we can do more things in the > > project, > > > > for > > > > > >> example, updating config in the user's `job submission system` > > after > > > > > >> scaling flink jobs. WDYT? > > > > > >> > > > > > >> Best, > > > > > >> Shammon > > > > > >> > > > > > >> > > > > > >> On Thu, Feb 16, 2023 at 7:38 PM Maximilian Michels < > > m...@apache.org> > > > > > >> wrote: > > > > > >> > > > > > >> > Hi Samrat, > > > > > >> > > > > > > >> > The autoscaling module is now pluggable but it is still > tightly > > > > > >> > coupled with Kubernetes. It will take additional work for the > > > logic > > > > to > > > > > >> > work independently of the cluster manager. > > > > > >> > > > > > > >> > -Max > > > > > >> > > > > > > >> > On Thu, Feb 16, 2023 at 11:14 AM Samrat Deb < > > > decordea...@gmail.com> > > > > > >> wrote: > > > > > >> > > > > > > > >> > > Oh! yesterday it got merged. > > > > > >> > > Apologies , I missed the recent commit @Gyula. > > > > > >> > > > > > > > >> > > Thanks for the update > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > > >> > > On Thu, Feb 16, 2023 at 3:17 PM Gyula Fóra < > > > gyula.f...@gmail.com> > > > > > >> wrote: > > > > > >> > > > > > > > >> > > > Max recently moved the autoscaler logic in a separate > > > submodule, > > > > > did > > > > > >> > you > > > > > >> > > > see that? > > > > > >> > > > > > > > > >> > > > > > > > > >> > > > > > > > > >> > > > > > > >> > > > > > > > > > > > > > > > https://github.com/apache/flink-kubernetes-operator/commit/5bb8e9dc4dd29e10f3ba7c8ce7cefcdffbf92da4 > > > > > >> > > > > > > > > >> > > > Gyula > > > > > >> > > > > > > > > >> > > > On Thu, Feb 16, 2023 at 10:27 AM Samrat Deb < > > > > > decordea...@gmail.com> > > > > > >> > wrote: > > > > > >> > > > > > > > > >> > > > > Hi , > > > > > >> > > > > > > > > > >> > > > > *Context:* > > > > > >> > > > > Auto Scaling was introduced in Flink as part of > > FLIP-271[1]. > > > > > >> > > > > It discusses one of the important aspects to provide a > > > robust > > > > > >> default > > > > > >> > > > > scaling algorithm. > > > > > >> > > > > a. Ensure scaling yields effective usage of > assigned > > > > task > > > > > >> > slots. > > > > > >> > > > > b. Ramp up in case of any backlog to ensure it > gets > > > > > >> processed > > > > > >> > in a > > > > > >> > > > > timely manner > > > > > >> > > > > c. Minimize the number of scaling decisions to > > prevent > > > > > >> costly > > > > > >> > > > rescale > > > > > >> > > > > operation > > > > > >> > > > > The flip intends to add an auto scaling framework based > > on 6 > > > > > major > > > > > >> > > > metrics > > > > > >> > > > > and contains different types of threshold to trigger the > > > > > scaling. > > > > > >> > > > > > > > > > >> > > > > Thread[2] discusses a different problem: why autoscaler > is > > > > part > > > > > of > > > > > >> > the > > > > > >> > > > > operator instead of jobmanager at runtime. > > > > > >> > > > > The Community decided to keep the autoscaling logic in > the > > > > > >> > > > > flink-kubernetes-operator. > > > > > >> > > > > > > > > > >> > > > > *Proposal: * > > > > > >> > > > > In this discussion, I want to put forward a thought of > > > > > extracting > > > > > >> > out the > > > > > >> > > > > auto scaling logic into a new submodule in > > > > > >> flink-kubernetes-operator > > > > > >> > > > > repository[3], > > > > > >> > > > > which will be independent of any resource > > manager/Operator. > > > > > >> > > > > Currently the Autoscaling algorithm is very tightly > > coupled > > > > with > > > > > >> the > > > > > >> > > > > kubernetes API. > > > > > >> > > > > This makes the autoscaling core algorithm not so easily > > > > > extensible > > > > > >> > for > > > > > >> > > > > different available resource managers like YARN, Mesos > > etc. > > > > > >> > > > > A Separate autoscaling module inside the flink > kubernetes > > > > > operator > > > > > >> > will > > > > > >> > > > > help other resource managers to leverage the autoscaling > > > > logic. > > > > > >> > > > > > > > > > >> > > > > [1] > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > >> > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-271%3A+Autoscaling > > > > > >> > > > > [2] > > > > > >> > https://lists.apache.org/thread/pvfb3fw99mj8r1x8zzyxgvk4dcppwssz > > > > > >> > > > > [3] https://github.com/apache/flink-kubernetes-operator > > > > > >> > > > > > > > > > >> > > > > > > > > > >> > > > > Bests, > > > > > >> > > > > Samrat > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > >> > > > > > > > > > > > > > > > > > > > > >
