Hi Chesnay,
IIUC, our only disagreement is whether to support task info in the
metric format. But we all agree with the default metric format
"metrics.scope.jm-operator=<host>.jobmanager.<job_name>.<operator_name>"
which doesn't include task info, right?
Regarding "coordinator metrics don't *belong to* any tasks/vertexes",
I mean the coordinator doesn't run on specific tasks, so it doesn't
have runtime information of tasks. My concern about adding task info
to the coordinator metric is that
1) if we register coordinator metrics for every subtask, the number of
coordinator metrics will be exploded when task parallelism is large.
This is an overhead to JM & metric systems, and the duplicated metrics
are useless for users.
2) Correct me if I'm wrong, MetricGroup#counter only supports
registering one metric. It seems it can't register a metric reporting
for multiple metric names (e.g. multiple subtasks).
Best,
Jark
On Mon, 30 Jan 2023 at 16:11, Chesnay Schepler <ches...@apache.org> wrote:
I hadn't looked in detail in to how the task info can be
introduced, but
given that the coordinates are created by the execution graph,
where we
only work on tasks, it should be possible and rather simple.
The OperatorCoordinatorHolder gets access to the
ExecutionJobVertex from
which it can extract everything and create the task/operator groups.
Exposure to the coordinator could happen via the coordinator
context as
originally planned.
> As we know, coordinator metrics are just like JMJobMetricGroup,
which
don't belong to any tasks/vertexes.
I don't think this is true, every coordinator is scoped to a specific
operator, and every operator is associated with a particular vertex.
From the javadocs:
" A coordinator for runtime operators. The OperatorCoordinator
runs on
the master, associated with
the job vertex of the operator. It communicates with operators via
sending operator events."
On 28/01/2023 09:15, Jark Wu wrote:
> Hi all,
>
> IIUC, Chesnay means we should have a more general metric group for
> **operator**
> not for **coordinator** in JM, this would be useful to extend
> other operator-specific
> metrics in the future. That means the new scope format should be
designed
> for
> the operator,
> e.g.,
metrics.scope.jm-operator=<host>.jobmanager.<job_name>.<operator_name>
> The coordinator metric is a subgroup (a constant "coordinator"
suffix) of
> the JMOperatorMG.
>
> I think this is a nice design. However, I have a question about
adding task
> id/name to this list.
> How to get the task id/name when reporting a coordinator metric?
As we
> know, coordinator metrics
> are just like JMJobMetricGroup, which don't belong to any
tasks/vertexes.
> Do you mean reporting
> coordinator metrics for every task id under the operator?
>
> Best,
> Jark
>
>
> On Thu, 19 Jan 2023 at 17:33, Chesnay Schepler
<ches...@apache.org> wrote:
>
>> > First, I do not understand why users have to configure the
new scope
>> format, which has a default value.
>>
>> If you don't use scope formats, sure. If you do use scope
formats, e.g.
>> to add a common prefix (which is the case for datadog users for
>> example), then the current default in the FLIP is insufficient and
>> requires the user to update the configuration.
>>
>> > I usually do not need to change these configuration of
scope formats
>> when submitting the flink job.
>>
>> Scope formats as a whole are quite a power-user feature, but that
>> doesn't mean we should ignore it.
>>
>> > I try to let it extend the ComponentMetricGroup
>>
>> This isn't inherently required just because it is a "component".
>> Component metric groups should _only_ be used for cases where
such a
>> component provides several bits of metadata.
>> For example, tasks provide vertex ids, task names, attempted
IDs etc.,
>> and we'd like users to have the option on how this metadata ends up
>> being used (via scope formats). This currently can't be built
with the
>> addGroup() methods, hence why the component groups exist.
>> However, the operator coordinator _itself_does not provide
several bits
>> of metadata. Logically, the _operator_ does, not the coordinator.
>>
>> > This make me decide to add a new scope format.
>>
>> And this is fine; just don't add a new scope format for the
coordinator
>> but logically for operators on the JM side, such that we can
extend the
>> set of operator-specific metrics in the future without having
to add yet
>> another scope format.
>>
>> > The relationship between the Operator and
OperatorCoordinator is
>> maintained in the OperatorCoordinatorHolder. In the POC, the
operator
>> name/id could be found and the OperatorCoordinatorMetricGroup
will be
>> created here.
>>
>> That's all irrelevant.
>>
>> > The registered metrics of OperatorCoordinator always are
those which
>> can not be aggregated from the tasks, like the number of unassigned
>> splits in the SourceCoordinator. Actually we have not
encountered the
>> scenario you mentioned. I think the OperatorCoordinatorMetricGroup
>> should only contain the metrics for itself instead of its subtasks.
>>
>> You are misunderstanding the problem.
>>
>> This isn't about aggregating metrics on our side or exposing
metrics
>> from TMs on the JM side or anything like that.
>>
>> It's purely about the available metadata for operator metrics
on the JM
>> side. Currently you suggest operator name / id; what I'm
proposing is to
>> add task(==vertex!) id / name to this list.
>>
>> The benefit here is simple. I can look up all metrics where
task_id==XXX
>> and get _everything_ related to that vertex, including all metrics
>> associated with operators that are part of that vertex,
including the
>> coordinator.
>>
>> > Using metrics.scope.jm.job is not enough to distinguish the
different
>> coordinators.
>>
>> I did not suggest just using metrics.scope.jm.job. I suggested
that as
>> the default for the jm operator scope format, that is used for the
>> proposed JobManagerOperatorMetricGroup, which will have some plain
>> metric groups as children for coordinators.
>> Aka, you have the JMOperatorMG, then you call
addGroup("coordinators")
>> and then addGroup(coordinator_name) for each coordinator.
>>
>> > So there are two choice for the
>> InternalOperatorCoordinatorMetricGroup: 1. add and improve the
new scope
>> format; 2. use the metrics.scope.jm.job and ProxyMetricGroup.
Which one
>> is better?
>>
>> There are more options than that.
>> I feel like there are a lot of misunderstandings in this
discussion.
>> Please let me know if I could clear things up. If not I can
also provide
>> a PoC based on your PoC if that can speed things up. It's not that
>> different anyway.
>>
>> On 19/01/2023 07:39, Hang Ruan wrote:
>>> Hi, chesnay,
>>>
>>> Thanks for your reply. I still have some doubts about the
questions
>>> you raised.
>>>
>>> > 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.
>>>
>>>
>>> First, I do not understand why users have to configure the new
scope
>>> format, which has a default value. I usually do not need to change
>>> these configuration of scope formats when submitting the flink
job.
>>> IMO, the OperatorCoordinator is a component running at the
JobMaster.
>>> I try to let it extend the ComponentMetricGroup, but I cannot find
>>> a suitable scope. This make me decide to add a new scope format.
>>>
>>> > 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.
>>>
>>>
>>> The relationship between the Operator and OperatorCoordinator is
>>> maintained in the OperatorCoordinatorHolder. In the POC, the
operator
>>> name/id could be found and the OperatorCoordinatorMetricGroup
will be
>>> created here.
>>>
>>> > 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.
>>>
>>>
>>> The registered metrics of OperatorCoordinator always are those
which
>>> can not be aggregated from the tasks, like the number of
unassigned
>>> splits in the SourceCoordinator. Actually we have not
encountered the
>>> scenario you mentioned. I think the OperatorCoordinatorMetricGroup
>>> should only contain the metrics for itself instead of its
subtasks.
>>>
>>> Using metrics.scope.jm.job is not enough to distinguish the
different
>>> coordinators. The operator id/name is necessary. Then
>>> the implementation should be like this. But users can not
change the
>>> scope in this way. This is also acceptable.
>>> @Internal public class InternalOperatorCoordinatorMetricGroup
>>> extends ProxyMetricGroup<MetricGroup>
>>> implements OperatorCoordinatorMetricGroup {
>>> public InternalOperatorCoordinatorMetricGroup(
>>> JobManagerJobMetricGroup parent, OperatorID
operatorID,
>> String operatorName) {
>>> super(parent.addGroup(operatorID +
>> operatorName).addGroup("coordinator")); }
>>> }
>>> So there are two choice for the
>>> InternalOperatorCoordinatorMetricGroup: 1. add and improve the new
>>> scope format; 2. use the metrics.scope.jm.job and
ProxyMetricGroup.
>>> Which one is better?
>>>
>>> Best,
>>> Hang
>>>
>>>
>>> Chesnay Schepler <ches...@apache.org> 于2023年1月18日周三
17:03写道：
>>>
>>> You're misunderstanding the problem.
>>>
>>> Metric groups form a tree with each group providing
certain metadata.
>>>
>>> E.g., on the taskmanager we have a TM metric group that
provides info
>>> about the TM, that has child task metric groups, that
have child
>>> operator metric groups etc. The operator metric group
again has
>>> children, where we are now mostly in the user/connector
land, like a
>>> kafka metric group providing partition info or something.
>>>
>>> What is being proposed is to create a coordinator metric
group on
>>> the JM
>>> side that provides operator metadata.
>>>
>>> A more appropriate structure is to create an operator
group on the JM
>>> side that provides this info, with the coordinator metric
group
>>> being a
>>> child.
>>>
>>> On 17/01/2023 19:56, Steven Wu wrote:
>>> >> 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
>>> >>
>>>
