I think <T extends ExternalResourceInfo> Set<T>
getExternalResourceInfos(String resourceName, Class<T>
externalResourceType) is not less flexible than the other API since you can
always pass in ExternalResourceInfo.class as the second argument.
The benefit I see for the user is that he does not have to do the
instanceof checks and type casts himself. This is admittedly not a big deal
but still a better API imo.
I think the interface of the Driver and what is returned by the
RuntimeContext don't have to have the same type because you can cast it or
repack it. If the current implementation simply stores what the Driver
returns and RuntimeContext returns this map, then it might seem that there
is a connection. But this should be an implementation detail rather than a
necessity.
Maybe we could also pull in someone from the SDK team to give us his
opinion on the user facing API.
Cheers,
Till
On Wed, Apr 15, 2020 at 10:13 AM Xintong Song <tonysong...@gmail.com> wrote:
> >
> > I agree that such an interface won't give compile time checks but I think
> > that it could be easier to use from a user's perspective because there is
> > no explicit casting required.
> > public interface RuntimeContext {
> > <T extends ExternalResourceInfo> Set<T>
> getExternalResourceInfos(String
> > resourceName, Class<T> externalResourceType);
> > }
>
>
> I'm not sure how less efforts is required from users to pass in a
> `externalResourceType` compared to do an explicit type casting.
> A potential side effect of passing in a `externalResourceType` is that, it
> requires user (e.g. the operator) to know which specific type should be
> returned in advance, which may limit the flexibility.
>
> E.g., we might have an operator that can work with multiple different
> implementations of `ExternalResourceInfo`. It may decide its behavior based
> on the actually type returned by `getExternalResourceInfos` at runtime.
>
>
> Thank you~
>
> Xintong Song
>
>
>
> On Wed, Apr 15, 2020 at 4:09 PM Yangze Guo <karma...@gmail.com> wrote:
>
> > @Till
> > If we add "Class<T> externalResourceType" param, what if there are
> > multiple subtypes in the ExternalResourceInfos set of one external
> > resource? It seems user has to set the T to ExternalResourceInfo and
> > the mechanism is useless at this case.
> >
> > Best,
> > Yangze Guo
> >
> > On Wed, Apr 15, 2020 at 3:57 PM Till Rohrmann <trohrm...@apache.org>
> > wrote:
> > >
> > > Ok, if there can be multiple resources of the same type then we
> > definitely
> > > need the name as a differentiator.
> > >
> > > I agree that such an interface won't give compile time checks but I
> think
> > > that it could be easier to use from a user's perspective because there
> is
> > > no explicit casting required.
> > >
> > > public interface RuntimeContext {
> > > <T extends ExternalResourceInfo> Set<T>
> > getExternalResourceInfos(String
> > > resourceName, Class<T> externalResourceType);
> > > }
> > >
> > > One minor note: I think the value of the returned map does not need to
> > use
> > > a bounded wildcard type because for the user it won't make a
> difference.
> > >
> > > Cheers,
> > > Till
> > >
> > > On Wed, Apr 15, 2020 at 8:20 AM Yangze Guo <karma...@gmail.com> wrote:
> > >
> > > > Hi Till,
> > > >
> > > > > ExternalResourceDriver could return a Set<? extends
> > > > ExternalResourceInfo>.
> > > > It sounds good.
> > > >
> > > > > then one could make the interface type-safe by changing it to
> > > > > public interface RuntimeContext {
> > > > > <T extends ExternalResourceInfo> Set<T>
> > > > > getExternalResourceInfo(Class<T> externalResourceType);
> > > > > }
> > > > I think it may not help.
> > > > - I think the assumption of "there is always only one resource of a
> > > > specific type" is too strong. The external resource framework should
> > > > only assume it gets a set of ExternalResourceInfo from the driver.
> The
> > > > concrete implementation is given by user. So, if we give such an
> > > > assumption, it would hurt the flexibility. There could be multiple
> > > > types in the returned externalResourceInfo set. There could also be
> > > > different types returned from different driver implementation or
> > > > version. The contract about the return type between Driver and
> > > > Operator should be guaranteed by user.
> > > > - Since the Drivers are loaded dynamically in runtime, if there is a
> > > > type mismatch, the job would fail in runtime instead of in compile
> > > > time, no matter the type extraction is done by Operator or Flink
> core.
> > > > This interface would not gain benefits for type safety.
> > > >
> > > > Best,
> > > > Yangze Guo
> > > >
> > > > On Wed, Apr 15, 2020 at 1:38 AM Till Rohrmann <trohrm...@apache.org>
> > > > wrote:
> > > > >
> > > > > Thanks for updating the FLIP, Yangze.
> > > > >
> > > > > If ExternalResourceInfo is a marker interface, then
> > > > ExternalResourceDriver
> > > > > could return a Set<? extends ExternalResourceInfo>. This makes is a
> > bit
> > > > > nicer for the implementor because he can use the concrete subtype.
> > > > >
> > > > > If we assume that users will always cast the ExternalResourceInfo
> > > > instance
> > > > > into the concrete subtype and if we assume that there is always
> only
> > one
> > > > > resource of a specific type, then one could make the interface
> > type-safe
> > > > by
> > > > > changing it to
> > > > >
> > > > > public interface RuntimeContext {
> > > > > <T extends ExternalResourceInfo> Set<T>
> > > > > getExternalResourceInfo(Class<T> externalResourceType);
> > > > > }
> > > > >
> > > > > If we want to support multiple GPU resources, then one would need
> to
> > use
> > > > > the name of the respective resource as well.
> > > > >
> > > > > Cheers,
> > > > > Till
> > > > >
> > > > > On Mon, Apr 13, 2020 at 4:19 AM Xintong Song <
> tonysong...@gmail.com>
> > > > wrote:
> > > > >
> > > > > > Thanks for updating the FLIP, Yangze.
> > > > > > The latest FLIP looks good to me.
> > > > > >
> > > > > > nit: Javadoc of `ExternalResourceDriver#retrieveResourceInfo` is
> > out of
> > > > > > sync.
> > > > > >
> > > > > > > Retrieve the information of the external resources according to
> > the
> > > > > > > resourceProfile.
> > > > > >
> > > > > >
> > > > > > Thank you~
> > > > > >
> > > > > > Xintong Song
> > > > > >
> > > > > >
> > > > > >
> > > > > > On Sat, Apr 11, 2020 at 11:04 AM Becket Qin <
> becket....@gmail.com>
> > > > wrote:
> > > > > >
> > > > > > > Good feedback form Xintong. The latest FLIP looks good to me.
> > > > > > >
> > > > > > > Thanks,
> > > > > > >
> > > > > > > Jiangjie (Becket) Qin
> > > > > > >
> > > > > > > On Sat, Apr 11, 2020 at 9:20 AM Yangze Guo <karma...@gmail.com
> >
> > > > wrote:
> > > > > > >
> > > > > > > > Hi there,
> > > > > > > > I've updated the FLIP accordingly. Please take a look. If you
> > have
> > > > any
> > > > > > > > further concerns please let me know.
> > > > > > > >
> > > > > > > > Best,
> > > > > > > > Yangze Guo
> > > > > > > >
> > > > > > > > On Fri, Apr 10, 2020 at 6:40 PM Yangze Guo <
> karma...@gmail.com
> > >
> > > > wrote:
> > > > > > > > >
> > > > > > > > > Thanks for the feedback, Xintong.
> > > > > > > > >
> > > > > > > > > - Should we have a factory interface for
> > > > `ExternalResourceDriver`,
> > > > > > that
> > > > > > > > > takes the configuration and returns a driver instance?
> > > > Otherwise, if
> > > > > > we
> > > > > > > > are
> > > > > > > > > creating the driver instance with reflection, we kind of
> > > > implicitly
> > > > > > > > > requires the driver to have a public non-argument
> > constructor.
> > > > If we
> > > > > > > > > decided to go with this approach, then we will not need
> > > > > > > > > `ExternalResourceDriver#open`.
> > > > > > > > >
> > > > > > > > > True, we could have an `ExternalResourceDriverFactory`,
> like
> > > > > > > > > interface ExternalResourceDriverFactory {
> > > > > > > > > ExternalResourceDriver fromConfiguration(Configuration
> > > > config);
> > > > > > > > > }
> > > > > > > > > Regarding the configuration, the user should provide
> > > > > > > > > "external-resource.{resourceName}.driver-factory.class"
> > instead.
> > > > > > > > >
> > > > > > > > > - Not sure about the necessity of
> > > > `ExternalResourceDriver#close`. I
> > > > > > > would
> > > > > > > > > suggest to avoid introduce more interfaces if not
> absolutely
> > > > > > necessary.
> > > > > > > > >
> > > > > > > > > I add `ExternalResourceDriver#close` in case user needs to
> > clean
> > > > up
> > > > > > > > > internal states and any other resources. It's true that it
> > may
> > > > not
> > > > > > > > > absolutely necessary for our GPUDriver. From my side, I'm
> ok
> > to
> > > > > > remove
> > > > > > > > > it.
> > > > > > > > >
> > > > > > > > > - `ExternalResourceDriver#retrieveResourceInfo` should not
> > take
> > > > > > > > > `ResourceProfile` as argument. This exposes more
> information
> > > > than it
> > > > > > > > needs.
> > > > > > > > > In addition, it requires the runtime/core to understand how
> > to
> > > > > > properly
> > > > > > > > > wrap the external resource into `ResourceProfile`. E.g.,
> > > > > > > > > `ResourceProfile#extendedResources` takes `Resource`, which
> > is an
> > > > > > > > abstract
> > > > > > > > > class. Runtime/core has to known which implementation of
> > > > `Resource`
> > > > > > to
> > > > > > > > use.
> > > > > > > > >
> > > > > > > > > True, at the moment, I think the amount of the resource is
> > > > enough for
> > > > > > > > > the `ExternalResourceDriver#retrieveResourceInfo`. In the
> > > > future, if
> > > > > > > > > the fine-grained external resource management is supported,
> > the
> > > > > > amount
> > > > > > > > > of the resource seems to be enough either. If we want to
> > leverage
> > > > > > some
> > > > > > > > > external resources which could not be measured by a single
> > long
> > > > > > value,
> > > > > > > > > we might enrich this. But I'd like to keep it out of the
> > scope of
> > > > > > this
> > > > > > > > > FLIP.
> > > > > > > > >
> > > > > > > > > - Do we really need `ExternalResourceInfo#getInformation`?
> I
> > > > think it
> > > > > > > > > should be good enough to make `ExternalResourceInfo` an
> empty
> > > > > > > interface.
> > > > > > > > > User can define their own `ExternalResourceInfo`
> > implementation
> > > > and
> > > > > > how
> > > > > > > > it
> > > > > > > > > is used by the operator user codes.
> > > > > > > > >
> > > > > > > > > Sounds good.
> > > > > > > > >
> > > > > > > > > Best,
> > > > > > > > > Yangze Guo
> > > > > > > > >
> > > > > > > > > On Fri, Apr 10, 2020 at 6:04 PM Xintong Song <
> > > > tonysong...@gmail.com>
> > > > > > > > wrote:
> > > > > > > > > >
> > > > > > > > > > Sorry to pull this back. I have some concerns about the
> > recent
> > > > > > > updated
> > > > > > > > > > interface details.
> > > > > > > > > >
> > > > > > > > > > - Should we have a factory interface for
> > > > `ExternalResourceDriver`,
> > > > > > > that
> > > > > > > > > > takes the configuration and returns a driver instance?
> > > > Otherwise,
> > > > > > if
> > > > > > > > we are
> > > > > > > > > > creating the driver instance with reflection, we kind of
> > > > implicitly
> > > > > > > > > > requires the driver to have a public non-argument
> > constructor.
> > > > If
> > > > > > we
> > > > > > > > > > decided to go with this approach, then we will not need
> > > > > > > > > > `ExternalResourceDriver#open`.
> > > > > > > > > > - Not sure about the necessity of
> > > > `ExternalResourceDriver#close`. I
> > > > > > > > would
> > > > > > > > > > suggest to avoid introduce more interfaces if not
> > absolutely
> > > > > > > necessary.
> > > > > > > > > > - `ExternalResourceDriver#retrieveResourceInfo` should
> not
> > take
> > > > > > > > > > `ResourceProfile` as argument. This exposes more
> > information
> > > > than
> > > > > > it
> > > > > > > > needs.
> > > > > > > > > > In addition, it requires the runtime/core to understand
> > how to
> > > > > > > properly
> > > > > > > > > > wrap the external resource into `ResourceProfile`. E.g.,
> > > > > > > > > > `ResourceProfile#extendedResources` takes `Resource`,
> > which is
> > > > an
> > > > > > > > abstract
> > > > > > > > > > class. Runtime/core has to known which implementation of
> > > > `Resource`
> > > > > > > to
> > > > > > > > use.
> > > > > > > > > > - Do we really need
> `ExternalResourceInfo#getInformation`?
> > I
> > > > think
> > > > > > it
> > > > > > > > > > should be good enough to make `ExternalResourceInfo` an
> > empty
> > > > > > > > interface.
> > > > > > > > > > User can define their own `ExternalResourceInfo`
> > > > implementation and
> > > > > > > > how it
> > > > > > > > > > is used by the operator user codes.
> > > > > > > > > >
> > > > > > > > > > Thank you~
> > > > > > > > > >
> > > > > > > > > > Xintong Song
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > On Thu, Apr 9, 2020 at 2:25 PM Becket Qin <
> > > > becket....@gmail.com>
> > > > > > > > wrote:
> > > > > > > > > >
> > > > > > > > > > > +1
> > > > > > > > > > >
> > > > > > > > > > > Thanks for driving this effort, Ynagze. The latest FLIP
> > wiki
> > > > > > looks
> > > > > > > > good to
> > > > > > > > > > > me.
> > > > > > > > > > >
> > > > > > > > > > > Cheers,
> > > > > > > > > > >
> > > > > > > > > > > Jiangjie (Becket) Qin
> > > > > > > > > > >
> > > > > > > > > > > On Wed, Apr 8, 2020 at 4:10 PM Yangze Guo <
> > > > karma...@gmail.com>
> > > > > > > > wrote:
> > > > > > > > > > >
> > > > > > > > > > > > Edit: RuntimeContext interface
> > > > > > > > > > > > From: Map<String, Set<ExternalResourceInfo>>
> > > > > > > > > > > > getExternalResourceInfo(ResourceSpec resourceSpec);
> > > > > > > > > > > > To: Map<String, Set<ExternalResourceInfo>>
> > > > > > > > getExternalResourceInfo();
> > > > > > > > > > > >
> > > > > > > > > > > > Best,
> > > > > > > > > > > > Yangze Guo
> > > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > On Wed, Apr 8, 2020 at 11:36 AM Yangze Guo <
> > > > karma...@gmail.com
> > > > > > >
> > > > > > > > wrote:
> > > > > > > > > > > > >
> > > > > > > > > > > > > Hi, there
> > > > > > > > > > > > >
> > > > > > > > > > > > > I have updated the FLIP, mainly target to make it
> > more
> > > > > > detailed
> > > > > > > > and
> > > > > > > > > > > > > clear. The general design is not changed, but there
> > are
> > > > still
> > > > > > > > some
> > > > > > > > > > > > > changes need to be notified here:
> > > > > > > > > > > > >
> > > > > > > > > > > > > - Change the `ExternalResourceDriver` from abstract
> > > > class to
> > > > > > > > > > > > > interface, since it does not have an abstract
> > > > implementation.
> > > > > > > > Add life
> > > > > > > > > > > > > cycle method `open` and `close`.
> > > > > > > > > > > > >
> > > > > > > > > > > > > - Specify the method added to the RuntimeContext
> from
> > > > which
> > > > > > > user
> > > > > > > > get
> > > > > > > > > > > > > the information of external resources.
> > > > > > > > > > > > > Map<String, Set<ExternalResourceInfo>>
> > > > > > > > > > > > > getExternalResourceInfo(ResourceSpec resourceSpec);
> > > > > > > > > > > > >
> > > > > > > > > > > > > - Add "String getInformation()" method to
> > > > > > > `ExternalResourceInfo`
> > > > > > > > > > > > interface.
> > > > > > > > > > > > >
> > > > > > > > > > > > > - Treat adding external resource info to
> > RestAPI/WebUI
> > > > as a
> > > > > > > > future
> > > > > > > > > > > work.
> > > > > > > > > > > > >
> > > > > > > > > > > > > If you have any new concerns after that change,
> > please
> > > > > > > mentioned
> > > > > > > > here.
> > > > > > > > > > > > > Sorry for disturbing you.
> > > > > > > > > > > > >
> > > > > > > > > > > > > Best,
> > > > > > > > > > > > > Yangze Guo
> > > > > > > > > > > > >
> > > > > > > > > > > > > On Wed, Apr 8, 2020 at 9:55 AM Yang Wang <
> > > > > > > danrtsey...@gmail.com>
> > > > > > > > > > > wrote:
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > Thanks Yangze for the efforts to support GPU
> > extended
> > > > > > > > resources.
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > +1 for this FLIP
> > > > > > > > > > > > > >
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > Best,
> > > > > > > > > > > > > > Yang
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > Till Rohrmann <trohrm...@apache.org>
> 于2020年4月2日周四
> > > > > > 下午11:10写道：
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > > Thanks for driving this effort Yangze.
> > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > +1
> > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > Cheers,
> > > > > > > > > > > > > > > Till
> > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > On Wed, Apr 1, 2020 at 12:41 PM Canbin Zheng <
> > > > > > > > > > > felixzhen...@gmail.com
> > > > > > > > > > > > >
> > > > > > > > > > > > > > > wrote:
> > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > Thanks Yangze for driving the initial CPU
> > support!
> > > > > > > > > > > > > > > > +1 (non-binding) from my side.
> > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > Xintong Song <tonysong...@gmail.com>
> > 于2020年4月1日周三
> > > > > > > > 下午6:36写道：
> > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > Thanks Yangze, the FLIP looks good to me.
> > > > > > > > > > > > > > > > > +1 (non-binding) from my side.
> > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > Thank you~
> > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > Xintong Song
> > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > On Wed, Apr 1, 2020 at 5:22 PM Yangze Guo <
> > > > > > > > karma...@gmail.com>
> > > > > > > > > > > > wrote:
> > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > > Hi everyone,
> > > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > > I'd like to start the vote of FLIP-108
> [1],
> > > > which
> > > > > > > adds
> > > > > > > > GPU
> > > > > > > > > > > > support in
> > > > > > > > > > > > > > > > > > Flink. This FLIP is discussed in the
> > thread[2].
> > > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > > The vote will be open for at least 72
> > hours.
> > > > Unless
> > > > > > > > there is
> > > > > > > > > > > an
> > > > > > > > > > > > > > > > > objection,
> > > > > > > > > > > > > > > > > > I will try to close it by April 4, 2020
> > 10:00
> > > > UTC
> > > > > > if
> > > > > > > > we have
> > > > > > > > > > > > received
> > > > > > > > > > > > > > > > > > sufficient votes.
> > > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > > [1]
> > > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > >
> >
> https://cwiki.apache.org/confluence/display/FLINK/FLIP-108%3A+Add+GPU+support+in+Flink
> > > > > > > > > > > > > > > > > > [2]
> > > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > >
> >
> http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/DISCUSS-FLIP-108-Add-GPU-support-in-Flink-td38286.html
> > > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > > > Best,
> > > > > > > > > > > > > > > > > > Yangze Guo
> > > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > > >
> > > > > > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > >
> >
>
