Hi Zakelly, Thanks for your proposal. The FLIP looks good to me +1! I'd like to ask some minor questions I found that there is also a definition of class `FutureUtils` under `org. apache. flink. util. concurrent` which seems to offer more interfaces. My question is: 1. Is it possible for all `FutureUtils` in Flink to reuse the same util class? 2. It seems that there is no concept of retry, timeout, or delay in your async state api design . Do we need to provide such capabilities like `orTimeout` 、`completeDelayed`?
Jing Ge <j...@ververica.com.invalid> 于2024年3月13日周三 20:00写道： > indeed! I missed that part. Thanks for the hint! > > Best regards, > Jing > > On Wed, Mar 13, 2024 at 6:02 AM Zakelly Lan <zakelly....@gmail.com> wrote: > > > Hi Jing, > > > > The deprecation and removal of original APIs is beyond the scope of > > current FLIP, but I do add/highlight such information under > "Compatibility, > > Deprecation, and Migration Plan" section. > > > > > > Best, > > Zakelly > > > > On Wed, Mar 13, 2024 at 9:18 AM Yunfeng Zhou < > flink.zhouyunf...@gmail.com> > > wrote: > > > >> Hi Zakelly, > >> > >> Thanks for your responses. I agree with it that we can keep the design > >> as it is for now and see if others have any better ideas for these > >> questions. > >> > >> Best, > >> Yunfeng > >> > >> On Tue, Mar 12, 2024 at 5:23 PM Zakelly Lan <zakelly....@gmail.com> > >> wrote: > >> > > >> > Hi Xuannan, > >> > > >> > Thanks for your comments, I modified the FLIP accordingly. > >> > > >> > Hi Yunfeng, > >> > > >> > Thanks for sharing your opinions! > >> > > >> >> Could you provide some hint on use cases where users need to mix sync > >> >> and async state operations in spite of the performance regression? > >> >> This information might help address our concerns on design. If the > >> >> mixed usage is simply something not recommended, I would prefer to > >> >> prohibit such usage from API. > >> > > >> > In fact, there is no scenario where users MUST use the sync APIs, but > >> it is much easier to use for those who are not familiar with > asynchronous > >> programming. If they want to migrate their job from Flink 1.x to 2.0 > >> leveraging some benefits from asynchronous APIs, they may try the mixed > >> usage. It is not user-friendly to directly throw exceptions at runtime, > I > >> think our better approach is to warn users and recommend avoiding this. > I > >> added an example in this FLIP. > >> > > >> > Well, I do not insist on allowing mixed usage of APIs if others reach > >> an agreement that we won't support that . I think the most important is > to > >> keep the API easy to use and understand, thus I propose a unified state > >> declaration and explicit meaning in method name. WDYT? > >> > > >> >> Sorry I missed the new sink API. I do still think that it would be > >> >> better to make the package name more informative, and ".v2." does not > >> >> contain information for new Flink users who did not know the v1 of > >> >> state API. Unlike internal implementation and performance > >> >> optimization, API will hardly be compromised for now and updated in > >> >> future, so I still suggest we improve the package name now if > >> >> possible. But given the existing practice of sink v2 and > >> >> AbstractStreamOperatorV2, the current package name would be > acceptable > >> >> to me if other reviewers of this FLIP agrees on it. > >> > > >> > Actually, I don't like 'v2' either. So if there is another good name, > >> I'd be happy to apply. This is a compromise to the current situation. > Maybe > >> we could refine this after the retirement of original state APIs. > >> > > >> > > >> > Thanks & Best, > >> > Zakelly > >> > > >> > > >> > On Tue, Mar 12, 2024 at 1:42 PM Yunfeng Zhou < > >> flink.zhouyunf...@gmail.com> wrote: > >> >> > >> >> Hi Zakelly, > >> >> > >> >> Thanks for the quick response! > >> >> > >> >> > Actually splitting APIs into two sets ... warn them in runtime. > >> >> > >> >> Could you provide some hint on use cases where users need to mix sync > >> >> and async state operations in spite of the performance regression? > >> >> This information might help address our concerns on design. If the > >> >> mixed usage is simply something not recommended, I would prefer to > >> >> prohibit such usage from API. > >> >> > >> >> > In fact ... .sink2`. > >> >> > >> >> Sorry I missed the new sink API. I do still think that it would be > >> >> better to make the package name more informative, and ".v2." does not > >> >> contain information for new Flink users who did not know the v1 of > >> >> state API. Unlike internal implementation and performance > >> >> optimization, API will hardly be compromised for now and updated in > >> >> future, so I still suggest we improve the package name now if > >> >> possible. But given the existing practice of sink v2 and > >> >> AbstractStreamOperatorV2, the current package name would be > acceptable > >> >> to me if other reviewers of this FLIP agrees on it. > >> >> > >> >> Best, > >> >> Yunfeng > >> >> > >> >> On Mon, Mar 11, 2024 at 5:27 PM Zakelly Lan <zakelly....@gmail.com> > >> wrote: > >> >> > > >> >> > Hi Yunfeng, > >> >> > > >> >> > Thanks for your comments! > >> >> > > >> >> > +1 for JingGe's suggestion to introduce an AsyncState API, instead > of > >> >> > > having both get() and asyncGet() in the same State class. As a > >> >> > > supplement to its benefits, this design could help avoid having > >> users > >> >> > > to use sync and async API in a mixed way (unless they create > both a > >> >> > > State and an AsyncState from the same state descriptor), which is > >> >> > > supposed to bring suboptimal performance according to the FLIP's > >> >> > > description. > >> >> > > >> >> > > >> >> > Actually splitting APIs into two sets of classes also brings some > >> >> > difficulties. In this case, users must explicitly define their > usage > >> before > >> >> > actually doing state access. It is a little strange that the user > can > >> >> > define a sync and an async version of State with the same name, > >> while they > >> >> > cannot allocate two async States with the same name. > >> >> > Another reason for distinguishing API by their method name instead > >> of class > >> >> > name is that users typically use the State instances to access > state > >> but > >> >> > forget their type/class. For example: > >> >> > ``` > >> >> > SyncState a = getState(xxx); > >> >> > AsyncState b = getAsyncState(xxx); > >> >> > //... > >> >> > a.update(1); > >> >> > b.update(1); > >> >> > ``` > >> >> > Users are likely to think there is no difference between the > >> `a.update(1)` > >> >> > and `b.update(1)`, since they may forget the type for `a` and `b`. > >> Thus I > >> >> > proposed to distinguish the behavior in method names. > >> >> > As for the suboptimal performance with mixed usage of sync and > >> async, my > >> >> > proposal is to warn them in runtime. > >> >> > > >> >> > I noticed that the FLIP proposes to place the newly introduced API > in > >> >> > > the package "org.apache.flink.api.common.state.v2", which seems a > >> >> > > little strange to me as there has not been such a naming pattern > >> >> > > ".v2." for packages in Flink. > >> >> > > >> >> > > >> >> > In fact, there are some similar existing patterns, like > >> >> > `org.apache.flink.streaming.api.functions.sink.v2` and > >> >> > `org.apache.flink.streaming.api.connector.sink2`. > >> >> > > >> >> > I would suggest discussing this topic > >> >> > > with the main authors of Datastream V2, like Weijie Guo, so that > >> the > >> >> > > newly introduced APIs from both sides comply with a unified > naming > >> >> > > style. > >> >> > > >> >> > I'm afraid we are facing a different situation with the Datastream > >> V2. For > >> >> > total reconstruction of Datastream API, it is big enough to build a > >> >> > seperate module and keep good package names. While for state APIs, > we > >> >> > should stay in the flink-core(-api) module alongside with other > >> >> > apis, currently I tend to compromise at the expense of naming > style. > >> >> > > >> >> > > >> >> > Looking forward to hearing from you again! > >> >> > > >> >> > Thanks & Best, > >> >> > Zakelly > >> >> > > >> >> > On Mon, Mar 11, 2024 at 4:20 PM Yunfeng Zhou < > >> flink.zhouyunf...@gmail.com> > >> >> > wrote: > >> >> > > >> >> > > Hi Zakelly, > >> >> > > > >> >> > > Thanks for the proposal! The structure of the Async API generally > >> >> > > looks good to me. Some comments on the details of the design are > as > >> >> > > follows. > >> >> > > > >> >> > > +1 for JingGe's suggestion to introduce an AsyncState API, > instead > >> of > >> >> > > having both get() and asyncGet() in the same State class. As a > >> >> > > supplement to its benefits, this design could help avoid having > >> users > >> >> > > to use sync and async API in a mixed way (unless they create > both a > >> >> > > State and an AsyncState from the same state descriptor), which is > >> >> > > supposed to bring suboptimal performance according to the FLIP's > >> >> > > description. > >> >> > > > >> >> > > I noticed that the FLIP proposes to place the newly introduced > API > >> in > >> >> > > the package "org.apache.flink.api.common.state.v2", which seems a > >> >> > > little strange to me as there has not been such a naming pattern > >> >> > > ".v2." for packages in Flink. I would suggest discussing this > topic > >> >> > > with the main authors of Datastream V2, like Weijie Guo, so that > >> the > >> >> > > newly introduced APIs from both sides comply with a unified > naming > >> >> > > style. If we reach an agreement on the first comment, my personal > >> idea > >> >> > > is that we can place the AsyncState interfaces to > >> >> > > "org.apache.flink.api.common.state.async", and the existing state > >> APIs > >> >> > > to "org.apache.flink.api.common.state" or > >> >> > > "org.apache.flink.api.common.state.sync". > >> >> > > > >> >> > > Best regards, > >> >> > > Yunfeng Zhou > >> >> > > > >> >> > > On Thu, Mar 7, 2024 at 4:48 PM Zakelly Lan < > zakelly....@gmail.com> > >> wrote: > >> >> > > > > >> >> > > > Hi devs, > >> >> > > > > >> >> > > > I'd like to start a discussion on a sub-FLIP of FLIP-423: > >> Disaggregated > >> >> > > > State Storage and Management[1], which is a joint work of Yuan > >> Mei, > >> >> > > Zakelly > >> >> > > > Lan, Jinzhong Li, Hangxiang Yu, Yanfei Lei and Feng Wang: > >> >> > > > > >> >> > > > - FLIP-424: Asynchronous State APIs [2] > >> >> > > > > >> >> > > > This FLIP introduces new APIs for asynchronous state access. > >> >> > > > > >> >> > > > Please make sure you have read the FLIP-423[1] to know the > whole > >> story, > >> >> > > and > >> >> > > > we'll discuss the details of FLIP-424[2] under this mail. For > the > >> >> > > > discussion of overall architecture or topics related with > >> multiple > >> >> > > > sub-FLIPs, please post in the previous mail[3]. > >> >> > > > > >> >> > > > Looking forward to hearing from you! > >> >> > > > > >> >> > > > [1] https://cwiki.apache.org/confluence/x/R4p3EQ > >> >> > > > [2] https://cwiki.apache.org/confluence/x/SYp3EQ > >> >> > > > [3] > >> https://lists.apache.org/thread/ct8smn6g9y0b8730z7rp9zfpnwmj8vf0 > >> >> > > > > >> >> > > > > >> >> > > > Best, > >> >> > > > Zakelly > >> >> > > > >> > > > -- Best, Yue
