Hi Kostas & Aljoscha,
I'm drafting a plan exposing multi-layered clients. It is mainly about
how we distinguish different layers and what clients we're going to
expose.
In FLIP-73 scope I'd like to ask a question that whether or not Executor
becomes a public interface that can be made use of by downstream
project developer? Or it just an internal concept for unifying job
submission?
If it is the latter, I'm feeling multi-layer client topic is totally
independent from
Executor.
Best,
tison.
Thomas Weise <t...@apache.org> 于2019年10月5日周六 上午12:17写道：
> It might be useful to mention on FLIP-73 that the intention for
> Executor.execute is to be an asynchronous API once it becomes public and
> also refer to FLIP-74 as such.
>
>
> On Fri, Oct 4, 2019 at 2:52 AM Aljoscha Krettek <aljos...@apache.org>
> wrote:
>
> > Hi Tison,
> >
> > I agree, for now the async Executor.execute() is an internal detail but
> > during your work for FLIP-74 it will probably also reach the public API.
> >
> > Best,
> > Aljoscha
> >
> > > On 4. Oct 2019, at 11:39, Zili Chen <wander4...@gmail.com> wrote:
> > >
> > > Hi Aljoscha,
> > >
> > > After clearly narrow the scope of this FLIP it looks good to me the
> > > interface
> > > Executor and its discovery so that I'm glad to see the vote thread.
> > >
> > > As you said, we should still discuss on implementation details but I
> > don't
> > > think
> > > it should be a blocker of the vote thread because a vote means we
> > generally
> > > agree on the motivation and overall design.
> > >
> > > As for Executor.execute() to be async, it is much better than we keep
> the
> > > difference between sync/async in this level. But I'd like to note that
> it
> > > only
> > > works internally for now because user-facing interface is still
> > env.execute
> > > which block and return a JobExecutionResult. I'm afraid that there are
> > > several
> > > people depends on the result for doing post execution process, although
> > it
> > > doesn't
> > > work on current per-job mode.
> > >
> > > Best,
> > > tison.
> > >
> > >
> > > Aljoscha Krettek <aljos...@apache.org> 于2019年10月4日周五 下午4:40写道：
> > >
> > >> Do you all think we could agree on the basic executor primitives and
> > start
> > >> voting on this FLIP? There are still some implementation details but I
> > >> think we can discuss/tackle them when we get to them and the various
> > people
> > >> implementing this should be in close collaboration.
> > >>
> > >> Best,
> > >> Aljoscha
> > >>
> > >>> On 4. Oct 2019, at 10:15, Aljoscha Krettek <aljos...@apache.org>
> > wrote:
> > >>>
> > >>> Hi,
> > >>>
> > >>> I think the end goal is to have only one environment per API, but I
> > >> think we won’t be able to achieve that in the short-term because of
> > >> backwards compatibility. This is most notable with the context
> > environment,
> > >> preview environments etc.
> > >>>
> > >>> To keep this FLIP very slim we can make this only about the executors
> > >> and executor discovery. Anything else like job submission semantics,
> > >> detached mode, … can be tackled after this. If we don’t focus I’m
> afraid
> > >> this will drag on for quite a while.
> > >>>
> > >>> One thing I would like to propose to make this easier is to change
> > >> Executor.execute() to return a CompletableFuture and to completely
> > remove
> > >> the “detached” logic from ClusterClient. That way, the new components
> > make
> > >> no distinction between “detached” and “attached” but we can still do
> it
> > in
> > >> the CLI (via the ContextEnvironment) to support the existing
> “detached”
> > >> behaviour of the CLI that users expect. What do you think about this?
> > >>>
> > >>> Best,
> > >>> Aljoscha
> > >>>
> > >>>> On 3. Oct 2019, at 10:03, Zili Chen <wander4...@gmail.com> wrote:
> > >>>>
> > >>>> Thanks for your explanation Kostas to make it clear subtasks under
> > >> FLIP-73.
> > >>>>
> > >>>> As you described, changes of Environment are included in this FLIP.
> > For
> > >>>> "each
> > >>>> API to have a single Environment", it could be helpful to describe
> > which
> > >>>> APIs we'd
> > >>>> like to have after FLIP-73. And if we keep multiple Environments,
> > shall
> > >> we
> > >>>> keep the
> > >>>> way inject context environment for each API?
> > >>>>
> > >>>>
> > >>>> Kostas Kloudas <kklou...@gmail.com> 于2019年10月3日周四 下午1:44写道：
> > >>>>
> > >>>>> Hi Tison,
> > >>>>>
> > >>>>> The changes that this FLIP propose are:
> > >>>>> - the introduction of the Executor interface
> > >>>>> - the fact that everything in the current state of job submission
> in
> > >>>>> Flink can be defined through configuration parameters
> > >>>>> - implementation of Executors that do not change any of the
> semantics
> > >>>>> of the currently offered "modes" of job submission
> > >>>>>
> > >>>>> In this, and in the FLIP itself where the
> > >>>>> ExecutionEnvironment.execute() method is described, there are
> details
> > >>>>> about parts of the
> > >>>>> integration with the existing Flink code-base.
> > >>>>>
> > >>>>> So I am not sure what do you mean by making the "integration a
> > >>>>> follow-up discussion".
> > >>>>>
> > >>>>> Cheers,
> > >>>>> Kostas
> > >>>>>
> > >>>>> On Wed, Oct 2, 2019 at 8:10 PM Zili Chen <wander4...@gmail.com>
> > wrote:
> > >>>>>>
> > >>>>>> - for Preview/OptimizedPlanEnv: I think they are orthogonal to the
> > >>>>>> Executors work, as they are using the exexute() method because
> this
> > is
> > >>>>>> the only "entry" to the user program. To this regard, I believe we
> > >>>>>> should just see the fact that they have their dedicated
> environment
> > as
> > >>>>>> an "implementation detail".
> > >>>>>>
> > >>>>>> The proposal says
> > >>>>>>
> > >>>>>> In this document, we propose to abstract away from the
> Environments
> > >> the
> > >>>>> job
> > >>>>>> submission logic and put it in a newly introduced Executor. This
> > will
> > >>>>>> allow *each
> > >>>>>> API to have a single Environment* which, based on the provided
> > >>>>>> configuration, will decide which executor to use, *e.g.* Yarn,
> > Local,
> > >>>>> etc.
> > >>>>>> In addition, it will allow different APIs and downstream projects
> to
> > >>>>> re-use
> > >>>>>> the provided executors, thus limiting the amount of code
> duplication
> > >> and
> > >>>>>> the amount of code that has to be written.
> > >>>>>>
> > >>>>>> note that This will allow *each API to have a single Environment*
> > it
> > >>>>>> seems a bit diverge with you statement above. Or we say a single
> > >>>>> Environment
> > >>>>>> as a possible advantage after the introduction of Executor so that
> > we
> > >>>>>> exclude it
> > >>>>>> from this pass.
> > >>>>>>
> > >>>>>> Best,
> > >>>>>> tison.
> > >>>>>>
> > >>>>>>
> > >>>>>> Zili Chen <wander4...@gmail.com> 于2019年10月3日周四 上午2:07写道：
> > >>>>>>
> > >>>>>>> BTW, correct me if I misunderstand, now I learn more about our
> > >>>>> community
> > >>>>>>> way. Since FLIP-73 aimed at introducing an interface with
> community
> > >>>>>>> consensus the discussion is more about the interface in order to
> > >>>>> properly
> > >>>>>>> define a useful and extensible API. The integration story could
> be
> > a
> > >>>>>>> follow up
> > >>>>>>> since this one does not affect current behavior at all.
> > >>>>>>>
> > >>>>>>> Best,
> > >>>>>>> tison.
> > >>>>>>>
> > >>>>>>>
> > >>>>>>> Zili Chen <wander4...@gmail.com> 于2019年10月3日周四 上午2:02写道：
> > >>>>>>>
> > >>>>>>>> Hi Kostas,
> > >>>>>>>>
> > >>>>>>>> It seems does no harm we have a configuration parameter of
> > >>>>>>>> Executor#execute
> > >>>>>>>> since we can merge this one with the one configured on Executor
> > >>>>> created
> > >>>>>>>> and
> > >>>>>>>> let this one overwhelm that one.
> > >>>>>>>>
> > >>>>>>>> I can see it is useful that conceptually we can create an
> Executor
> > >>>>> for a
> > >>>>>>>> series jobs
> > >>>>>>>> to the same cluster but with different job configuration per
> > >> pipeline.
> > >>>>>>>>
> > >>>>>>>> Best,
> > >>>>>>>> tison.
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>> Kostas Kloudas <kklou...@apache.org> 于2019年10月3日周四 上午1:37写道：
> > >>>>>>>>
> > >>>>>>>>> Hi again,
> > >>>>>>>>>
> > >>>>>>>>> I did not include this to my previous email, as this is related
> > to
> > >>>>> the
> > >>>>>>>>> proposal on the FLIP itself.
> > >>>>>>>>>
> > >>>>>>>>> In the existing proposal, the Executor interface is the
> > following.
> > >>>>>>>>>
> > >>>>>>>>> public interface Executor {
> > >>>>>>>>>
> > >>>>>>>>> JobExecutionResult execute(Pipeline pipeline) throws Exception;
> > >>>>>>>>>
> > >>>>>>>>> }
> > >>>>>>>>>
> > >>>>>>>>> This implies that all the necessary information for the
> execution
> > >> of
> > >>>>> a
> > >>>>>>>>> Pipeline should be included in the Configuration passed in the
> > >>>>>>>>> ExecutorFactory which instantiates the Executor itself. This
> > should
> > >>>>>>>>> include, for example, all the parameters currently supplied by
> > the
> > >>>>>>>>> ProgramOptions, which are conceptually not executor parameters
> > but
> > >>>>>>>>> rather parameters for the execution of the specific pipeline.
> To
> > >> this
> > >>>>>>>>> end, I would like to propose a change in the current Executor
> > >>>>>>>>> interface showcased below:
> > >>>>>>>>>
> > >>>>>>>>>
> > >>>>>>>>> public interface Executor {
> > >>>>>>>>>
> > >>>>>>>>> JobExecutionResult execute(Pipeline pipeline, Configuration
> > >>>>>>>>> executionOptions) throws Exception;
> > >>>>>>>>>
> > >>>>>>>>> }
> > >>>>>>>>>
> > >>>>>>>>> The above will allow to have the Executor specific options
> passed
> > >> in
> > >>>>>>>>> the configuration given during executor instantiation, while
> the
> > >>>>>>>>> pipeline specific options can be passed in the
> executionOptions.
> > >> As a
> > >>>>>>>>> positive side-effect, this will make Executors re-usable, i.e.
> > >>>>>>>>> instantiate an executor and use it to execute multiple
> pipelines,
> > >> if
> > >>>>>>>>> in the future we choose to do so.
> > >>>>>>>>>
> > >>>>>>>>> Let me know what do you think,
> > >>>>>>>>> Kostas
> > >>>>>>>>>
> > >>>>>>>>> On Wed, Oct 2, 2019 at 7:23 PM Kostas Kloudas <
> > kklou...@apache.org
> > >>>
> > >>>>>>>>> wrote:
> > >>>>>>>>>>
> > >>>>>>>>>> Hi all,
> > >>>>>>>>>>
> > >>>>>>>>>> I agree with Tison that we should disentangle threads so that
> > >>>>> people
> > >>>>>>>>>> can work independently.
> > >>>>>>>>>>
> > >>>>>>>>>> For FLIP-73:
> > >>>>>>>>>> - for Preview/OptimizedPlanEnv: I think they are orthogonal to
> > the
> > >>>>>>>>>> Executors work, as they are using the exexute() method because
> > >>>>> this is
> > >>>>>>>>>> the only "entry" to the user program. To this regard, I
> believe
> > we
> > >>>>>>>>>> should just see the fact that they have their dedicated
> > >>>>> environment as
> > >>>>>>>>>> an "implementation detail".
> > >>>>>>>>>> - for getting rid of the per-job mode: as a first note, there
> > was
> > >>>>>>>>>> already a discussion here:
> > >>>>>>>>>>
> > >>>>>>>>>
> > >>>>>
> > >>
> >
> https://lists.apache.org/thread.html/ce99cba4a10b9dc40eb729d39910f315ae41d80ec74f09a356c73938@%3Cdev.flink.apache.org%3E
> > >>>>>>>>>> with many people, including myself, expressing their opinion.
> I
> > am
> > >>>>>>>>>> mentioning that to show that this topic already has some
> history
> > >>>>> and
> > >>>>>>>>>> the discussin does not start from scratch but there are
> already
> > >>>>> some
> > >>>>>>>>>> contradicting opinions. My opinion is that we should not get
> rid
> > >> of
> > >>>>>>>>>> the per-job mode but I agree that we should discuss about the
> > >>>>>>>>>> semantics in more detail. Although in terms of code it may be
> > >>>>> tempting
> > >>>>>>>>>> to "merge" the two submission modes, one of the main benefits
> of
> > >>>>> the
> > >>>>>>>>>> per-job mode is isolation, both for resources and security, as
> > the
> > >>>>>>>>>> jobGraph to be executed is fixed and the cluster is "locked"
> > just
> > >>>>> for
> > >>>>>>>>>> that specific graph. This would be violated by having a
> session
> > >>>>>>>>>> cluster launched and having all the infrastrucutre (ports and
> > >>>>>>>>>> endpoints) set for submittting to that cluster any job.
> > >>>>>>>>>> - for getting rid of the "detached" mode: I agree with getting
> > rid
> > >>>>> of
> > >>>>>>>>>> it but this implies some potential user-facing changes that
> > should
> > >>>>> be
> > >>>>>>>>>> discussed.
> > >>>>>>>>>>
> > >>>>>>>>>> Given the above, I think that:
> > >>>>>>>>>> 1) in the context of FLIP-73 we should not change any
> semantics
> > >> but
> > >>>>>>>>>> simply push the existing submission logic behind a reusable
> > >>>>>>>>>> abstraction and make it usable via public APIs, as Aljoscha
> > said.
> > >>>>>>>>>> 2) as Till said, changing the semantics is beyond the scope of
> > >> this
> > >>>>>>>>>> FLIP and as Tison mentioned we should work towards decoupling
> > >>>>>>>>>> discussions rather than the opposite. So let's discuss about
> the
> > >>>>>>>>>> future of the per-job and detached modes in a separate thread.
> > >> This
> > >>>>>>>>>> will also allow to give the proper visibility to such an
> > important
> > >>>>>>>>>> topic.
> > >>>>>>>>>>
> > >>>>>>>>>> Cheers,
> > >>>>>>>>>> Kostas
> > >>>>>>>>>>
> > >>>>>>>>>> On Wed, Oct 2, 2019 at 4:40 PM Zili Chen <
> wander4...@gmail.com>
> > >>>>> wrote:
> > >>>>>>>>>>>
> > >>>>>>>>>>> Thanks for your thoughts Aljoscha.
> > >>>>>>>>>>>
> > >>>>>>>>>>> Another question since FLIP-73 might contains refactors on
> > >>>>>>>>> Environemnt:
> > >>>>>>>>>>> shall we support
> > >>>>>>>>>>> something like PreviewPlanEnvironment? If so, how? From a
> user
> > >>>>>>>>> perspective
> > >>>>>>>>>>> preview plan
> > >>>>>>>>>>> is useful, by give visual view, to modify topos and configure
> > >>>>> without
> > >>>>>>>>>>> submit it.
> > >>>>>>>>>>>
> > >>>>>>>>>>> Best,
> > >>>>>>>>>>> tison.
> > >>>>>>>>>>>
> > >>>>>>>>>>>
> > >>>>>>>>>>> Aljoscha Krettek <aljos...@apache.org> 于2019年10月2日周三
> > 下午10:10写道：
> > >>>>>>>>>>>
> > >>>>>>>>>>>> I agree with Till that we should not change the semantics of
> > >>>>>>>>> per-job mode.
> > >>>>>>>>>>>> In my opinion per-job mode means that the cluster
> (JobManager)
> > >>>>> is
> > >>>>>>>>> brought
> > >>>>>>>>>>>> up with one job and it only executes that one job. There
> > >>>>> should be
> > >>>>>>>>> no open
> > >>>>>>>>>>>> ports/anything that would allow submitting further jobs.
> This
> > >>>>> is
> > >>>>>>>>> very
> > >>>>>>>>>>>> important for deployments in docker/Kubernetes or other
> > >>>>>>>>> environments were
> > >>>>>>>>>>>> you bring up jobs without necessarily having the notion of a
> > >>>>> Flink
> > >>>>>>>>> cluster.
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> What this means for a user program that has multiple
> execute()
> > >>>>>>>>> calls is
> > >>>>>>>>>>>> that you will get a fresh cluster for each execute call.
> This
> > >>>>> also
> > >>>>>>>>> means,
> > >>>>>>>>>>>> that further execute() calls will only happen if the
> “client”
> > >>>>> is
> > >>>>>>>>> still
> > >>>>>>>>>>>> alive, because it is the one driving execution. Currently,
> > this
> > >>>>>>>>> only works
> > >>>>>>>>>>>> if you start the job in “attached” mode. If you start in
> > >>>>>>>>> “detached” mode
> > >>>>>>>>>>>> only the first execute() will happen and the rest will be
> > >>>>> ignored.
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> This brings us to the tricky question about what to do about
> > >>>>>>>>> “detached”
> > >>>>>>>>>>>> and “attached”. In the long run, I would like to get rid of
> > the
> > >>>>>>>>> distinction
> > >>>>>>>>>>>> and leave it up to the user program, by either blocking or
> not
> > >>>>> on
> > >>>>>>>>> the
> > >>>>>>>>>>>> Future (or JobClient or whatnot) that job submission
> returns.
> > >>>>> This,
> > >>>>>>>>>>>> however, means that users cannot simply request “detached”
> > >>>>>>>>> execution when
> > >>>>>>>>>>>> using bin/flink, the user program has to “play along”. On
> the
> > >>>>>>>>> other hand,
> > >>>>>>>>>>>> “detached” mode is quite strange for the user program. The
> > >>>>>>>>> execute() call
> > >>>>>>>>>>>> either returns with a proper job result after the job ran
> (in
> > >>>>>>>>> “attached”
> > >>>>>>>>>>>> mode) or with a dummy result (in “detached” mode) right
> after
> > >>>>>>>>> submission. I
> > >>>>>>>>>>>> think this can even lead to weird cases where multiple
> > >>>>> "execute()”
> > >>>>>>>>> run in
> > >>>>>>>>>>>> parallel. For per-job detached mode we also “throw” out of
> the
> > >>>>>>>>> first
> > >>>>>>>>>>>> execute so the rest (including result processing logic) is
> > >>>>> ignored.
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> For this here FLIP-73 we can (and should) ignore these
> > >>>>> problems,
> > >>>>>>>>> because
> > >>>>>>>>>>>> FLIP-73 only moves the existing submission logic behind a
> > >>>>> reusable
> > >>>>>>>>>>>> abstraction and makes it usable via API. We should closely
> > >>>>> follow
> > >>>>>>>>> up on the
> > >>>>>>>>>>>> above points though because I think they are also important.
> > >>>>>>>>>>>>
> > >>>>>>>>>>>> Best,
> > >>>>>>>>>>>> Aljoscha
> > >>>>>>>>>>>>
> > >>>>>>>>>>>>> On 2. Oct 2019, at 12:08, Zili Chen <wander4...@gmail.com>
> > >>>>>>>>> wrote:
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>>> Thanks for your clarification Till.
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>>> I agree with the current semantics of the per-job mode, one
> > >>>>>>>>> should
> > >>>>>>>>>>>> deploy a
> > >>>>>>>>>>>>> new cluster for each part of the job. Apart from the
> > >>>>> performance
> > >>>>>>>>> concern
> > >>>>>>>>>>>>> it also means that PerJobExecutor knows how to deploy a
> > >>>>> cluster
> > >>>>>>>>> actually,
> > >>>>>>>>>>>>> which is different from the description that Executor
> submit
> > >>>>> a
> > >>>>>>>>> job.
> > >>>>>>>>>>>>>
> > >>>>>>>>>>>>> Anyway it sounds workable and narrow the changes.
> > >>>>>>>>>>>>
> > >>>>>>>>>>>>
> > >>>>>>>>>
> > >>>>>>>>
> > >>>>>
> > >>>
> > >>
> > >>
> >
> >
>
