> Additionally, the configurable variables (operator name/id) are logically not attached to the coordinator, but operators, so to me it just doesn't make sense to structure it like this.
Chesnay, maybe we should clarify the terminology. To me, pperators (like FLIP-27 source) can have two parts (coordinator and reader/subtask). I think it is fine to include operator name/id for coordinator metrics. On Mon, Jan 16, 2023 at 2:13 AM Chesnay Schepler <ches...@apache.org> wrote: > Slight correction: Using metrics.scope.jm.job as the default should be > safe. > > On 16/01/2023 10:18, Chesnay Schepler wrote: > > The proposed ScopeFormat is still problematic for a few reasons. > > > > Extending the set of ScopeFormats is problematic because it in > > practice it breaks the config if users actively rely on it, since > > there's now another key that they _must_ set for it to be > > consistent/compatible with their existing setup. > > Unfortunately due to how powerful scope formats are we can't derive a > > default value that matches their existing setup. > > Hence we should try to do this as rarely as possible. > > > > This FLIP does not adhere to that since it proposes a dedicated format > > for coordinators; next time we want to expose operator-specific > > metrics (e.g., in the scheduler) we'd have to add another one to > > support it. > > > > Additionally, the configurable variables (operator name/id) are > > logically not attached to the coordinator, but operators, so to me it > > just doesn't make sense to structure it like this. > > > > Another thing I'm concerned about is that, because we don't include > > tasks in the hierarchy, users wishing to collect all metrics for a > > particular task (in this case ==vertex) now have to go significantly > > out of their way to get them, since they can no longer just filter by > > the task ID but have to be filter for _all_ operators that are part of > > the task. > > > > On 16/01/2023 03:09, Hang Ruan wrote: > >> Hi, @ches...@apache.org <ches...@apache.org> , > >> > >> Do you have time to help to review this FLIP again after the > >> modification? > >> Looking forward to your reply. > >> This FLIP will add a new configuration for the > >> OperatorCoordinatorMetricGroup scope format. It provides an internal > >> implementation and is added as a component to the > >> JobManagerJobMetricGroup. > >> If something doesn't make sense, could you provide some advice? It > >> will be > >> very helpful. Thanks a lot for your help. > >> > >> Best, > >> Hang > >> > >> Martijn Visser <martijnvis...@apache.org> 于2023年1月11日周三 16:34写道： > >> > >> > >>> Hi Hang, > >>> > >>> I'm a bit surprised that this has gone to a vote, given that Chesnay > >>> deliberately mentioned that he would vote against it as-is. I would > >>> expect > >>> that before going to a vote, he has had the opportunity to > >>> participate in > >>> this discussion. > >>> > >>> Best regards, > >>> > >>> Martijn > >>> > >>> On Tue, Jan 3, 2023 at 12:53 PM Jark Wu <imj...@gmail.com> wrote: > >>> > >>>> Hi Dong, > >>>> > >>>> Regarding “SplitEnumeratorContext#metricGroup”, my only concern is > >>>> that > >>>> this is a core interface for the FLIP. It’s hard to tell how > >>>> sources use > >>>> metric group without mentioning this interface. Even if this is an > >>> existing > >>>> API, I think it’s worth introducing the interface again and declaring > >>> that > >>>> we will implement the interface instead of a no-op method in this > >>>> FLIP. > >>>> > >>>> Anyway, this is a minor problem and shouldn’t block this FLIP. I’m > >>>> +1 to > >>>> start a vote. > >>>> > >>>> Best, > >>>> Jark > >>>> > >>>> > >>>>> 2023年1月3日 10:03，Hang Ruan <ruanhang1...@gmail.com> 写道： > >>>>> > >>>>> Hi, Jark and Dong, > >>>>> > >>>>> Thanks for your comments. Sorry for my late reply. > >>>>> > >>>>> For suggestion 1, I plan to implement the > >>>>> SplitEnumeratorMetricGroup in > >>>>> another issue, and it is not contained in this FLIP. I will add some > >>>>> description about this part. > >>>>> For suggestion 2, changes about OperatorCoordinator#metricGroup has > >>>> already > >>>>> been documented in the proposed change section. > >>>>> > >>>>> Best, > >>>>> Hang > >>>>> > >>>>> Dong Lin <lindon...@gmail.com> 于2023年1月1日周日 09:45写道： > >>>>> > >>>>>> Let me chime-in and add comments regarding the public interface > >>> section. > >>>>>> Please see my comments inline. > >>>>>> > >>>>>> On Thu, Dec 29, 2022 at 6:08 PM Jark Wu <imj...@gmail.com> wrote: > >>>>>> > >>>>>>> Hi Hang, > >>>>>>> > >>>>>>> Thanks for driving this discussion. I think this is a very useful > >>>> feature > >>>>>>> for connectors. > >>>>>>> > >>>>>>> The FLIP looks quite good to me, and I just have two suggestions. > >>>>>>> > >>>>>>> 1. In the "Public Interface" section, mention that the > >>>>>>> implementation > >>>>>>> behavior of "SplitEnumeratorContext#metricGroup" is changed from > >>>>>> returning > >>>>>>> null to returning a concrete SplitEnumeratorMetricGroup instance. > >>> Even > >>>>>>> though the API is already there, the behavior change can also be > >>>>>> considered > >>>>>>> a public change. > >>>>>>> > >>>>>> SplitEnumeratorContext#metricGroup is an interface and this FLIP > >>>>>> does > >>>> not > >>>>>> seem to change its semantics/behavior. The FLIP does change the > >>>>>> implementation/behavior of SourceCoordinatorContext#metricGroup, > >>>>>> which > >>>> is > >>>>>> marked @Internal. > >>>>>> > >>>>>> Thus it might seem a bit weird to add in the public interface > >>>>>> section > >>>>>> saying that we change the interface > >>>>>> SplitEnumeratorContext#metricGroup > >>>> from > >>>>>> returning null to non-null object. > >>>>>> > >>>>>> 2. Mention the newly added interface of > >>>> "OperatorCoordinator#metricGroup" > >>>>>>> in the "Proposed Changes" section or "Public Interface" section. As > >>> the > >>>>>>> FLIP said, OperatorCoordinator is widely used in many connectors. > >>>> Though > >>>>>> it > >>>>>>> is still an @Internal API, I think it is worth mentioning the > >>>>>>> change > >>> in > >>>>>> the > >>>>>>> FLIP. > >>>>>> > >>>>>> Since OperatorCoordinator is an internal API, it seems reasonable to > >>>>>> explain it in the proposed change section. The FLIP seems to have > >>>>>> documented this in point 5 of the proposed change section. > >>>>>> > >>>>>> BTW, if we think there are @internal classes that are important > >>>>>> enough > >>>> to > >>>>>> be added in the public interface section, it might be useful to > >>>> explicitly > >>>>>> discuss this topic and document it in the "*What are the "public > >>>>>> interfaces" of the project*" in this > >>>>>> < > >>>>>> > >>> > https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals > >>> > >>>>>> wiki. > >>>>>> > >>>>>> > >>>>>>> Best, > >>>>>>> Jark > >>>>>>> > >>>>>>> > >>>>>>> On Mon, 26 Dec 2022 at 18:06, Hang Ruan <ruanhang1...@gmail.com> > >>>> wrote: > >>>>>>>> Hi, thanks for the feedback, Zhu Zhu and Qingsheng. > >>>>>>>> After combining everyone's comments, the main concerns and > >>>>>> corresponding > >>>>>>>> adjustments are as follows. > >>>>>>>> > >>>>>>>> Q1: Common metrics are not quite useful. > >>>>>>>> numEventsIn and numEventsOut counters will be removed from the > >>>>>>>> OperatorCoordinatorMetricGroup. These common metrics do not > >>>>>>>> provide > >>>>>>> enough > >>>>>>>> information for users. The users are more willing to get the > >>>>>>>> number > >>> of > >>>>>>>> events of the specified type instead of the total number. And this > >>>>>> metric > >>>>>>>> is calculated differently. The implementation could register the > >>>> metric > >>>>>>> by > >>>>>>>> themselves. > >>>>>>>> > >>>>>>>> Q2: This FLIP is overly complicated. > >>>>>>>> This FLIP will become concise after these modifications. > >>>>>>>> OperatorCoordinatorMetricGroup has already been introduced into > >>> Flink > >>>>>> by > >>>>>>>> FLIP-179< > >>>>>>>> > >>>>>>>> > >>> > https://cwiki.apache.org/confluence/display/FLINK/FLIP-179%3A+Expose+Standardized+Operator+Metrics > >>> > >>>>>>>>> . > >>>>>>>> And > >>>>>>>> this FLIP will not change it. This FLIP only provides a new metric > >>>>>> option > >>>>>>>> and a new metric group scope. The changes in proposed changes > >>> provide > >>>>>> the > >>>>>>>> details about the modifications for the internal classes, which > >>> might > >>>>>>> make > >>>>>>>> it look complicated. > >>>>>>>> > >>>>>>>> Thanks for all the comments again. If there are no further > >>>>>>>> comments, > >>>> we > >>>>>>>> plan to start the voting thread this week. > >>>>>>>> > >>>>>>>> Best, > >>>>>>>> Hang > >>>>>>>> > >>>>>>>> Qingsheng Ren <renqs...@gmail.com> 于2022年12月26日周一 16:48写道： > >>>>>>>> > >>>>>>>> > >>>>>>>>> Thanks for the FLIP, Hang! > >>>>>>>>> > >>>>>>>>> This FLIP overall looks good to me. Actually I share the same > >>> concern > >>>>>>>> with > >>>>>>>>> Zhu that numEventsIn and numEventsOut counters are not quite > >>>>>>>>> useful > >>>>>> to > >>>>>>>> end > >>>>>>>>> users. OperatorEvent is a quite low-level abstraction, which > >>> requires > >>>>>>>>> instantialization in order to be practical to users and > >>>>>>>>> developers, > >>>>>> so > >>>>>>>>> maybe it's better to exclude them from the FLIP. > >>>>>>>>> > >>>>>>>>> Best, > >>>>>>>>> Qingsheng > >>>>>>>>> Ververica (Alibaba) > >>>>>>>>> > >>>>>>>>> On Mon, Dec 26, 2022 at 12:08 PM Zhu Zhu <reed...@gmail.com> > >>> wrote: > >>>>>>>>>> Hi Hang, > >>>>>>>>>> I still see no strong reason why we need > >>>>>>>>>> numEventsIn/numEventsOut > >>>>>>>>> metrics. > >>>>>>>>>> In the discussion in FLINK-29801, I can see the same concern > >>>>>>>>>> from > >>>>>>>> others. > >>>>>>>>>> So I prefer to exclude them from this FLIP to avoid > >>>>>>>>>> over-extending > >>>>>>> the > >>>>>>>>>> scope. > >>>>>>>>>> > >>>>>>>>>> Thanks, > >>>>>>>>>> Zhu > >>>>>>>>>> > >>>>>>>>>> Hang Ruan <ruanhang1...@gmail.com> 于2022年12月23日周五 > >>>>>>>>>> 15:21写道： > >>>>>>>>>>> Hi everyone, > >>>>>>>>>>> > >>>>>>>>>>> As for the Zhu Zhu's problem, I think we should keep the common > >>>>>>>>> metrics, > >>>>>>>>>> which will help to observe incoming and outgoing events. What do > >>>>>> you > >>>>>>>>> think, > >>>>>>>>>> @Zhu Zhu ? > >>>>>>>>>>> And @Chesnay, are there any other issues you are more concerned > >>>>>>>> about? > >>>>>>>>>> Looking forward to your reply. > >>>>>>>>>>> Thanks for all the comments. If there are no further > >>>>>>>>>>> comments, we > >>>>>>>> plan > >>>>>>>>>> to start the voting thread next week. > >>>>>>>>>>> Best, > >>>>>>>>>>> Hang > >>>>>>>>>>> > >>>>>>>>>>> Hang Ruan <ruanhang1...@gmail.com> 于2022年12月15日周四 > >>>>>>>>>>> 16:49写道： > >>>>>>>>>>>> Hi, Zhu Zhu, > >>>>>>>>>>>> > >>>>>>>>>>>> Thanks for your feedback! > >>>>>>>>>>>> > >>>>>>>>>>>> The OperatorCoordinator implementations are different. And > >>>>>>>>>>>> their > >>>>>>>>>> metrics are much different too. We try to find the common > >>>>>>>>>> metrics > >>>>>> and > >>>>>>>> put > >>>>>>>>>> them in the OperatorCoordinatorMetricGroup. If most developers > >>>>>> think > >>>>>>> we > >>>>>>>>> do > >>>>>>>>>> not need these common metrics, removing the common metrics is > >>>>>>>>>> also > >>>>>>>>>> acceptable. > >>>>>>>>>>>> Best, > >>>>>>>>>>>> Hang > >>>>>>>>>>>> > >>>>>>>>>>>> Zhu Zhu <reed...@gmail.com> 于2022年12月14日周三 22:09写道： > >>>>>>>>>>>>> Hi Hang & MengYue, > >>>>>>>>>>>>> > >>>>>>>>>>>>> Thanks for creating this FLIP! > >>>>>>>>>>>>> > >>>>>>>>>>>>> I think it is very useful, mainly in two aspects: > >>>>>>>>>>>>> 1. Enables OperatorCoordinators to register metrics. > >>>>>>>>>>>>> Currently > >>>>>>>>>>>>> the coordinators has no way to do this. And operator > >>>>>> coordinator > >>>>>>>>>>>>> metric group further enables the SplitEnumerator to have > >>>>>>>>>>>>> access > >>>>>>>>>>>>> to a registered metric group (via the existing public > >>>>>>>>>>>>> interface > >>>>>>>>>>>>> SplitEnumeratorContext#metricGroup()), which is null at the > >>>>>>> moment. > >>>>>>>>>>>>> 2. Defines the scope of operator coordinator metrics. A clear > >>>>>>>>>> definition > >>>>>>>>>>>>> makes it easy for users to find their wanted metrics. The > >>>>>>>> definition > >>>>>>>>>>>>> also helps to avoid conflicts of metrics from multiple > >>>>>>>>>> OperatorCoordinators > >>>>>>>>>>>>> of the same kind. E.g. each SourceCoordinator may have its > >>>>>>>>>>>>> own > >>>>>>>>>>>>> numSourceSplits metric, these metrics should not be directly > >>>>>>>>> registered > >>>>>>>>>>>>> to the job metric group. > >>>>>>>>>>>>> > >>>>>>>>>>>>> What I'm a bit concerned is the necessity of the introduced > >>>>>>> common > >>>>>>>>>> metrics > >>>>>>>>>>>>> numEventsInCounter & numEventsOutCounter. If there any case > >>>>>> which > >>>>>>>>>> strongly > >>>>>>>>>>>>> requires them? > >>>>>>>>>>>>> > >>>>>>>>>>>>> Regarding the concerns of Chesnay, > >>>>>>>>>>>>>> A dedicated coordinator MG implementation is overkill > >>>>>>>>>>>>> Directly using the job metric group can result in metric > >>>>>>> conflicts, > >>>>>>>>> as > >>>>>>>>>> mentioned > >>>>>>>>>>>>> in above #2. > >>>>>>>>>>>>> > >>>>>>>>>>>>> Thanks, > >>>>>>>>>>>>> Zhu > >>>>>>>>>>>>> > >>>>>>>>>>>>> Dong Lin <lindon...@gmail.com> 于2022年12月10日周六 > >>>>>>>>>>>>> 14:16写道： > >>>>>>>>>>>>> > >>>>>>>>>>>>>> Hi Chesney, > >>>>>>>>>>>>>> > >>>>>>>>>>>>>> Just to double check with you, > >>>>>>>>>>>>>> OperatorCoordinatorMetricGroup > >>>>>>>>>> (annotated as > >>>>>>>>>>>>>> @PublicEvolving) has already been introduced into Flink by > >>>>>>>> FLIP-179 > >>>>>>>>>>>>>> < > >>> > https://cwiki.apache.org/confluence/display/FLINK/FLIP-179%3A+Expose+Standardized+Operator+Metrics > >>> > >>>>>>>>>>> . > >>>>>>>>>>>>>> And that FLIP has got you +1.. Do you mean we should remove > >>>>>>> this > >>>>>>>>>>>>>> OperatorCoordinatorMetricGroup? > >>>>>>>>>>>>>> > >>>>>>>>>>>>>> Regards, > >>>>>>>>>>>>>> Dong > >>>>>>>>>>>>>> > >>>>>>>>>>>>>> On Sat, Dec 10, 2022 at 1:33 AM Chesnay Schepler < > >>>>>>>>> ches...@apache.org> > >>>>>>>>>> wrote: > >>>>>>>>>>>>>>> As a whole I feel like this FLIP is overly complicated. A > >>>>>>>>> dedicated > >>>>>>>>>>>>>>> coordinator MG implementation is overkill; it could just > >>>>>>> re-use > >>>>>>>>> the > >>>>>>>>>>>>>>> existing Task/OperatorMGs to create the same structure we > >>>>>>> have > >>>>>>>> on > >>>>>>>>>> TMs, > >>>>>>>>>>>>>>> similar to what we did with the Job MG. > >>>>>>>>>>>>>>> > >>>>>>>>>>>>>>> However, I'm not convinced that this is required anyway, > >>>>>>>> because > >>>>>>>>>> all the > >>>>>>>>>>>>>>> example metrics you listed can be implemented on the TM > >>>>>> side > >>>>>>> + > >>>>>>>>>>>>>>> aggregating them in the external metrics backend. > >>>>>>>>>>>>>>> > >>>>>>>>>>>>>>> Since I'm on holidays soon, just so no one tries to pull a > >>>>>>> fast > >>>>>>>>>> one on > >>>>>>>>>>>>>>> me, if this were to go to a vote as-is I'd be against it. > >>>>>>>>>>>>>>> > >>>>>>>>>>>>>>> > >>>>>>>>>>>>>>> On 09/12/2022 15:30, Dong Lin wrote: > >>>>>>>>>>>>>>>> Hi Hang, > >>>>>>>>>>>>>>>> > >>>>>>>>>>>>>>>> Thanks for the FLIP! The FLIP looks good and it is pretty > >>>>>>>>>> informative. > >>>>>>>>>>>>>>>> I have just two minor comments regarding names: > >>>>>>>>>>>>>>>> - Would it be useful to rename the config key as > >>>>>>>>>>>>>>>> *metrics.scope.jm.job.operator-coordinator* for > >>>>>> consistency > >>>>>>>>> with > >>>>>>>>>>>>>>>> *metrics.scope.jm.job > >>>>>>>>>>>>>>>> *(which is not named as *jm-job)? > >>>>>>>>>>>>>>>> - Maybe rename the variable as > >>>>>>>>> SCOPE_NAMING_OPERATOR_COORDINATOR > >>>>>>>>>> for > >>>>>>>>>>>>>>>> simplicity and consistency with SCOPE_NAMING_OPERATOR > >>>>>>> (which > >>>>>>>> is > >>>>>>>>>> not named > >>>>>>>>>>>>>>>> as SCOPE_NAMING_TM_JOB_OPERATOR)? > >>>>>>>>>>>>>>>> > >>>>>>>>>>>>>>>> Cheers, > >>>>>>>>>>>>>>>> Dong > >>>>>>>>>>>>>>>> > >>>>>>>>>>>>>>>> > >>>>>>>>>>>>>>>> > >>>>>>>>>>>>>>>> On Thu, Dec 8, 2022 at 3:28 PM Hang Ruan < > >>>>>>>>> ruanhang1...@gmail.com> > >>>>>>>>>> wrote: > >>>>>>>>>>>>>>>>> Hi all, > >>>>>>>>>>>>>>>>> > >>>>>>>>>>>>>>>>> MengYue and I created FLIP-274[1] Introduce metric group > >>>>>>> for > >>>>>>>>>>>>>>>>> OperatorCoordinator. OperatorCoordinator is the > >>>>>>> coordinator > >>>>>>>>> for > >>>>>>>>>> runtime > >>>>>>>>>>>>>>>>> operators and running on Job Manager. The coordination > >>>>>>>>>> mechanism is > >>>>>>>>>>>>>>>>> operator events between OperatorCoordinator and its all > >>>>>>>>>> operators, the > >>>>>>>>>>>>>>>>> coordination is more and more using in Flink, for > >>>>>> example > >>>>>>>> many > >>>>>>>>>> Sources > >>>>>>>>>>>>>>> and > >>>>>>>>>>>>>>>>> Sinks depend on the mechanism to assign splits and > >>>>>>>> coordinate > >>>>>>>>>> commits to > >>>>>>>>>>>>>>>>> external systems. The OperatorCoordinator is widely > >>>>>> using > >>>>>>> in > >>>>>>>>>> flink kafka > >>>>>>>>>>>>>>>>> connector, flink pulsar connector, flink cdc connector, > >>>>>>>> flink > >>>>>>>>>> hudi > >>>>>>>>>>>>>>>>> connector and so on. > >>>>>>>>>>>>>>>>> > >>>>>>>>>>>>>>>>> But there is not a suitable metric group scope for the > >>>>>>>>>>>>>>> OperatorCoordinator > >>>>>>>>>>>>>>>>> and not an implementation for the interface > >>>>>>>>>>>>>>> OperatorCoordinatorMetricGroup. > >>>>>>>>>>>>>>>>> These metrics in OperatorCoordinator could be how many > >>>>>>>>>> splits/partitions > >>>>>>>>>>>>>>>>> have been assigned to source readers, how many files > >>>>>> have > >>>>>>>> been > >>>>>>>>>> written > >>>>>>>>>>>>>>> out > >>>>>>>>>>>>>>>>> by sink writers, these metrics not only help users to > >>>>>> know > >>>>>>>> the > >>>>>>>>>> job > >>>>>>>>>>>>>>> progress > >>>>>>>>>>>>>>>>> but also make big job maintaining easier. Thus we > >>>>>> propose > >>>>>>>> the > >>>>>>>>>> FLIP-274 > >>>>>>>>>>>>>>> to > >>>>>>>>>>>>>>>>> introduce a new metric group scope for > >>>>>> OperatorCoordinator > >>>>>>>> and > >>>>>>>>>> provide > >>>>>>>>>>>>>>> an > >>>>>>>>>>>>>>>>> internal implementation for > >>>>>>> OperatorCoordinatorMetricGroup. > >>>>>>>>>>>>>>>>> Could you help review this FLIP when you get time? Any > >>>>>>>>> feedback > >>>>>>>>>> is > >>>>>>>>>>>>>>>>> appreciated! > >>>>>>>>>>>>>>>>> > >>>>>>>>>>>>>>>>> Best, > >>>>>>>>>>>>>>>>> Hang > >>>>>>>>>>>>>>>>> > >>>>>>>>>>>>>>>>> [1] > >>>>>>>>>>>>>>>>> > >>>>>>>>>>>>>>>>> > >>> > https://cwiki.apache.org/confluence/display/FLINK/FLIP-274%3A+Introduce+metric+group+for+OperatorCoordinator > >>> > >>>>>>>>>>>>>>> > >>>> > > > >
