Hi Zakelly, Thanks for the proposal! I like this idea and I can see the performance improvements it brings.
In the previous reply you mentioned “these APIs are in some newly introduced classes, which are located in a different package name with the original one”. I can see the benefits of this. To be honest, there is a lot of historical burdens with the old state API, maybe this is a chance to break free. If I understand you correctly, the new State(V2) interface will still support synchronous API, right? But I didn't see that in the FLIP. Best regards, Weijie Zakelly Lan <zakelly....@gmail.com> 于2024年3月13日周三 13:03写道： > 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 > > >> > > > > >
