Hi all, Thanks for all. There are more questions and I will answer one by one.
@Jark Thanks for your tips. For the first question, I will add more details in the flip, and give a POC[1] so that pepole can know how I'm currently implementing these features. > IIRC, this is the first time we introduce the framework-level connector > options that the option is not recognized and handled by connectors. > The FLIP should cover how framework filters the watermark related options > to avoid discover connector factory failed, and what happens if the > connector already supported the conflict options For the second question, We know that the default strategy is 'on-periodic' in SQL layer, and the default interval is 200ms. The reason for emiting watermark periodically is that the time advancement of consecutive events may be very small, we don't need to calculate watermark for each event. Same for 'on-event' strategy, so my idea is that we can set a fixed gap for 'on-event' strategy. > I'm not sure about the usage scenarios of event gap emit strategy. Do > you have any specific use case of this strategy? I'm confused why no one > requested this strategy before no matter in DataStream or SQL, but maybe > I missed something. I'm not against to add this option, but just want to be > careful when adding new API because it's hard to remove in the future. As @Timo said, There is no default features like 'on-event-gap' in DataStream API, but the users can achieve the 'on-event-gap' feature by using `WatermarkGenerator` interface, just like the implemention in my POC[1]. However, If we don't provide it in SQL layer, there is no way for users to use similar features. > Jark raised a very good point. I thought we only expose what is > contained in DataStream API already. If this strategy is not part of > DataStream API, would like to exclude it from the FLIP. We need to be > careful which strategies we offer by default. @Jark @Timo I'm sorry, perhaps I don't understand what are your concerns about CompiledPlan, maybe I missed something else, maybe you can look at my POC first to see if there is somewhere to worry about. > Sorry, I forgot to remind you that Timo's concern about the changes to the > CompiledPlan looks like is still not covered in the FLIP. @Jing We could have more discussion about naming, but I prefer that the naming should be consistent with the DataStream API. About aligning splits/partitions/shards, maybe you missed FLIP-217[2] which aims to support watermark alignment of source splits. > After reading the most up-to-date Flip, I didn't find any information if > this solution will support aligning splits/partitions/shards [1]. Did I > miss anything? Best Kui Yuan [1] the POC: https://github.com/yuchengxin/flink/tree/yuankui/watermark_params [2] FLIP-217: https://cwiki.apache.org/confluence/display/FLINK/FLIP-217%3A+Support+watermark+alignment+of+source+splits Jing Ge <j...@ververica.com.invalid> 于2023年3月3日周五 08:03写道： > Hi, > > Thanks Kui for driving this Flip and thanks all for the informative > discussion. > > @Timo > > Your suggestion about the naming convention is excellent. Thanks! I was > wondering why you, exceptionally, suggested 'scan.idle-timeout' instead of > 'scan.watermark.idle-timeout'. I must miss something here. > > There is one more NIT. I am just aware that "drift" is used for the > watermark alignment. It seems to be fine while using DataStream API, > because we will not really see it. But with the OPTIONS in SQL, a much > bigger group of users (including SRE, tech support, etc) will see the word > "drift". Given that "drift" wasn't used widely yet and with all training > materials, Flink doc [1][2][3] (search with "lag"), "lag" has been used to > describe timestamp difference between watermark and its > corresponding event. Do we really need to introduce another term for the > same thing? How about using 'scan.watermark.alignment.max-lag'='1min' and > change the parameter name from maxAllowedWatermarkDrift to > maxAllowedWatermarkLag [4] because of naming consistency? Just my two cents > worth. > > @Kui > > After reading the most up-to-date Flip, I didn't find any information if > this solution will support aligning splits/partitions/shards [1]. Did I > miss anything? > > +1 for the concern about Table API. We'd be better keep Table API and SQL > synced for new features. > > Best regards, > Jing > > > [1] > > https://nightlies.apache.org/flink/flink-docs-release-1.16/docs/dev/datastream/event-time/generating_watermarks/#watermark-alignment-_beta_ > [2] > > https://nightlies.apache.org/flink/flink-docs-release-1.16/docs/dev/datastream/event-time/built_in/#fixed-amount-of-lateness > > [3] > > https://nightlies.apache.org/flink/flink-docs-release-1.16/docs/connectors/datastream/kafka/ > [4] > > https://github.com/apache/flink/blob/4aacff572a9e3996c5dee9273638831e4040c767/flink-core/src/main/java/org/apache/flink/api/common/eventtime/WatermarkStrategy.java#L169 > > > > On Wed, Mar 1, 2023 at 3:54 PM Timo Walther <twal...@apache.org> wrote: > > > Reg. 2: > > > event gap emit strategy [...] no matter in DataStream or SQL > > > > Jark raised a very good point. I thought we only expose what is > > contained in DataStream API already. If this strategy is not part of > > DataStream API, would like to exclude it from the FLIP. We need to be > > careful which strategies we offer by default. > > > > Reg 1: > > This already has a JIRA ticket with additional thoughts on this topic: > > https://issues.apache.org/jira/browse/FLINK-25221 > > > > Regards, > > Timo > > > > > > > > On 01.03.23 12:31, Jark Wu wrote: > > > Sorry, I forgot to remind you that Timo's concern about the changes to > > the > > > CompiledPlan looks like is still not covered in the FLIP. > > > > > > Best, > > > Jark > > > > > > On Wed, 1 Mar 2023 at 19:28, Jark Wu <imj...@gmail.com> wrote: > > > > > >> Hi Kui, > > >> > > >> Thank you for the great proposal, I think this is already in a good > > shape. > > >> > > >> Just a kind reminder, according to the community guidelines[1], > > >> if there are unresponsive reviewers, a typical reasonable time > > >> to wait for responses is one week, but be pragmatic about it. > > >> > > >> Regarding the FLIP, I have some comments below: > > >> > > >> 1. IIRC, this is the first time we introduce the framework-level > > connector > > >> options that the option is not recognized and handled by connectors. > > >> The FLIP should cover how framework filters the watermark related > > options > > >> to avoid discover connector factory failed, and what happens if the > > >> connector > > >> already supported the conflict options. > > >> > > >> 2. I'm not sure about the usage scenarios of event gap emit strategy. > Do > > >> you have any specific use case of this strategy? I'm confused why no > one > > >> requested this strategy before no matter in DataStream or SQL, but > maybe > > >> I missed something. I'm not against to add this option, but just want > to > > >> be > > >> careful when adding new API because it's hard to remove in the future. > > >> > > >> > > >> 3. Adding a "Public Interface"[2] section to summarize the > > >> proposed APIs and options would be better for developers to > > >> know the impact. Currently, the APIs are scattered in the long > > >> design sections. > > >> > > >> Best, > > >> Jark > > >> > > >> > > >> [1]: > > >> > > > https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals > > >> [2]: https://cwiki.apache.org/confluence/display/FLINK/FLIP+Template > > >> > > >> On Wed, 1 Mar 2023 at 16:56, Kui Yuan <catye...@gmail.com> wrote: > > >> > > >>> Hi all, > > >>> > > >>> Thanks for all discussions! > > >>> > > >>> Anyone else have questions or suggestions? if not, I will start a > vote > > >>> thread later. > > >>> > > >>> Best > > >>> Kui Yuan > > >>> > > >>> kui yuan <catye...@gmail.com> 于2023年2月27日周一 20:21写道： > > >>> > > >>>> Hi Timo, > > >>>> > > >>>> Thanks for your advice. I totally agree with your suggestion of > naming > > >>>> convention, I will rename these options and update the flip later, > > >>> thanks > > >>>> very much. > > >>>> > > >>>> In our internal implementation we had put these options inside the > > >>>> `FactoryUtil`, just as you expect. We have also taken into account > > the > > >>>> changes to the CompiledPlan and we have packaged these options > > >>>> appropriately to minimize intrusiveness and ensure the compatibility > > to > > >>> the > > >>>> `WatermarkPushDownSpec`. > > >>>> > > >>>>> A hint to the implementation: I would suggest that we add those > > >>> options > > >>>>> to `FactoryUtil`. All cross-connector options should end up there. > > >>>> > > >>>> > > >>>>> Please also consider the changes to the CompiledPlan in your FLIP. > > >>> This > > >>>>> change has implications on the JSON format as watermark strategy of > > >>>>> ExecNode becomes more complex, see WatermarkPushDownSpec > > >>>> > > >>>> Best > > >>>> Kui Yuan > > >>>> > > >>>> Timo Walther <twal...@apache.org> 于2023年2月27日周一 18:05写道： > > >>>> > > >>>>> Hi Kui Yuan, > > >>>>> > > >>>>> thanks for working on this FLIP. Let me also give some comments > about > > >>>>> the proposed changes. > > >>>>> > > >>>>> I support the direction of this FLIP about handling these > > >>>>> watermark-specific properties through options and /*+OPTIONS(...) > */ > > >>>>> hints. > > >>>>> > > >>>>> Regarding naming, I would like to keep the options in sync with > > >>> existing > > >>>>> options: > > >>>>> > > >>>>> > 'watermark.emit.strategy'='ON_EVENT' > > >>>>> > > >>>>> Let's use lower case (e.g. `on-event`) that matches with properties > > >>> like > > >>>>> sink.partitioner [1] or sink.delivery-guarantee [2]. > > >>>>> > > >>>>> > 'source.idle-timeout'='1min' > > >>>>> > > >>>>> According to FLIP-122 [3], we want to prefix all scan-source > related > > >>>>> properties with `scan.*`. This clearly includes idle-timeout and > > >>>>> actually also watermark strategies which don't apply for lookup > > >>> sources. > > >>>>> > > >>>>> Summarizing the comments above, we should use the following > options: > > >>>>> > > >>>>> 'scan.watermark.emit.strategy'='on-event', > > >>>>> 'scan.watermark.emit.on-event.gap'='10000', > > >>>>> 'scan.idle-timeout'='1min', > > >>>>> 'scan.watermark.alignment.group'='alignment-group-1', > > >>>>> 'scan.watermark.alignment.max-drift'='1min', > > >>>>> 'scan.watermark.alignment.update-interval'='1s' > > >>>>> > > >>>>> I know that this makes the keys even longer, but given that those > > >>>>> options are for power users this should be acceptable. It also > > clearly > > >>>>> indicates which options are for sinks, scans, and lookups. This > > >>>>> potentially also helps in allow lists. > > >>>>> > > >>>>> A hint to the implementation: I would suggest that we add those > > options > > >>>>> to `FactoryUtil`. All cross-connector options should end up there. > > >>>>> > > >>>>> Please also consider the changes to the CompiledPlan in your FLIP. > > This > > >>>>> change has implications on the JSON format as watermark strategy of > > >>>>> ExecNode becomes more complex, see WatermarkPushDownSpec [4]. > > >>>>> > > >>>>> Regards, > > >>>>> Timo > > >>>>> > > >>>>> > > >>>>> [1] > > >>>>> > > >>>>> > > >>> > > > https://nightlies.apache.org/flink/flink-docs-release-1.11/dev/table/connectors/kafka.html#sink-partitioner > > >>>>> [2] > > >>>>> > > >>>>> > > >>> > > > https://nightlies.apache.org/flink/flink-docs-release-1.16/docs/connectors/table/kafka/#sink-delivery-guarantee > > >>>>> [3] > > >>>>> > > >>>>> > > >>> > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-122%3A+New+Connector+Property+Keys+for+New+Factory > > >>>>> [4] > > >>>>> > > >>>>> > > >>> > > > https://github.com/apache/flink/blob/master/flink-table/flink-table-planner/src/main/java/org/apache/flink/table/planner/plan/abilities/source/WatermarkPushDownSpec.java > > >>>>> > > >>>>> > > >>>>> On 24.02.23 04:55, kui yuan wrote: > > >>>>>> Hi all, > > >>>>>> > > >>>>>> I have updated the flip according to the discussion, and we will > > >>> extend > > >>>>> the > > >>>>>> watermark-related features with both table options and 'OPTIONS' > > >>> hint, > > >>>>> like > > >>>>>> this: > > >>>>>> > > >>>>>> ``` > > >>>>>> -- configure in table options > > >>>>>> CREATE TABLE user_actions ( > > >>>>>> ... > > >>>>>> user_action_time TIMESTAMP(3), > > >>>>>> WATERMARK FOR user_action_time AS user_action_time - INTERVAL > > '5' > > >>>>> SECOND > > >>>>>> ) WITH ( > > >>>>>> 'watermark.emit.strategy'='ON_PERIODIC', > > >>>>>> ... > > >>>>>> ); > > >>>>>> > > >>>>>> -- use 'OPTIONS' hint > > >>>>>> select ... from source_table /*+ > OPTIONS('watermark.emit.strategy'= > > >>>>>> 'ON_PERIODIC') */ > > >>>>>> ``` > > >>>>>> > > >>>>>> Does everybody have any other questions? > > >>>>>> > > >>>>>> Best > > >>>>>> Kui Yuan > > >>>>>> > > >>>>>> kui yuan <catye...@gmail.com> 于2023年2月23日周四 20:05写道： > > >>>>>> > > >>>>>>> Hi all, > > >>>>>>> > > >>>>>>> Thanks for all suggestions. > > >>>>>>> > > >>>>>>> We will extend the watermark-related features in SQL layer with > > >>> dynamic > > >>>>>>> table options and 'OPTIONS' hint, just as everyone expects. I > will > > >>>>> modify > > >>>>>>> Flip-296 as discussed. > > >>>>>>> > > >>>>>>> @Martijn As far as I know, there is no hint interface in the > table > > >>> API, > > >>>>>>> so we can't use hint in table API directly. if we need to extend > > the > > >>>>> hint > > >>>>>>> interface in the table API, maybe we need another flip. However, > if > > >>> we > > >>>>>>> extend the watermark-related features in the dynamic table > options, > > >>>>> maybe > > >>>>>>> we are able to use them indirectly in the table API like this[1]: > > >>>>>>> > > >>>>>>> ``` > > >>>>>>> // register a table named "Orders" > > >>>>>>> tableEnv.executeSql("CREATE TABLE Orders (`user` BIGINT, product > > >>>>> STRING, > > >>>>>>> amount INT) WITH ('watermark.emit.strategy'='ON_EVENT'...)"); > > >>>>>>> ``` > > >>>>>>> > > >>>>>>> [1] > > >>>>>>> > > >>>>> > > >>> > > > https://nightlies.apache.org/flink/flink-docs-master/docs/dev/table/sql/create/ > > >>>>>>> > > >>>>>>> Best > > >>>>>>> Kui Yuan > > >>>>>>> > > >>>>>>> Yun Tang <myas...@live.com> 于2023年2月23日周四 17:46写道： > > >>>>>>> > > >>>>>>>> Thanks for the warm discussions! > > >>>>>>>> > > >>>>>>>> I had an offline discussion with Kui about the replies. I think > I > > >>>>> could > > >>>>>>>> give some explanations on the original intention to introduce > > >>> another > > >>>>>>>> WATERMARK_PARAMS. If we take a look at the current datastream > API, > > >>> the > > >>>>>>>> watermark strategy does not belong to any specific connector. > And > > >>> we > > >>>>>>>> thought the dynamic table options were more like the > > configurations > > >>>>> within > > >>>>>>>> some specific connector. > > >>>>>>>> > > >>>>>>>> From the review comments, I think most people feel good to > make > > it > > >>>>> part > > >>>>>>>> of the dynamic table options. I think this is fine if we give > more > > >>>>> clear > > >>>>>>>> scope definition of the dynamic table options here. And I also > > >>> agree > > >>>>> with > > >>>>>>>> Jingsong's concern about adding SQL syntax which is the most > > >>>>> concerning > > >>>>>>>> part before launching this discussion. > > >>>>>>>> > > >>>>>>>> For Martijn's concern, if we accept to make the > watermark-related > > >>>>> options > > >>>>>>>> part of dynamic table options, the problem becomes another > topic: > > >>> how > > >>>>> to > > >>>>>>>> support the dynamic table options in table API, which is > deserved > > >>> to > > >>>>> create > > >>>>>>>> another FLIP. > > >>>>>>>> > > >>>>>>>> Best > > >>>>>>>> Yun Tang > > >>>>>>>> ________________________________ > > >>>>>>>> From: Martijn Visser <martijnvis...@apache.org> > > >>>>>>>> Sent: Thursday, February 23, 2023 17:14 > > >>>>>>>> To: dev@flink.apache.org <dev@flink.apache.org> > > >>>>>>>> Subject: Re: [DISCUSS] FLIP-296: Watermark options for table > API & > > >>> SQL > > >>>>>>>> > > >>>>>>>> Hi, > > >>>>>>>> > > >>>>>>>> While I can understand that there's a desire to first focus on > > >>> solving > > >>>>>>>> this > > >>>>>>>> problem for SQL, I do wonder if we should ignore the Table API > at > > >>> this > > >>>>>>>> point. If we could include the syntax for the Table API, it > > >>>>> potentially > > >>>>>>>> could also be implemented by another contributor without needing > > to > > >>>>> create > > >>>>>>>> another FLIP. If we don't design it right now, my concern is > that > > >>> this > > >>>>>>>> will > > >>>>>>>> increase sparsity for the Table API which ultimately hurts > > >>> adoption. > > >>>>>>>> > > >>>>>>>> With regards to the syntax, I have a preference to solve this > via > > >>> the > > >>>>>>>> connector options (e.g. like you can currently specify things as > > >>>>>>>> scan.startup.specific-offsets or scan.bounded.mode for the Kafka > > >>>>>>>> connector). You could still use the dynamic table options to > > >>>>> override/add > > >>>>>>>> them. > > >>>>>>>> > > >>>>>>>> Best regards, > > >>>>>>>> > > >>>>>>>> Martijn > > >>>>>>>> > > >>>>>>>> On Thu, Feb 23, 2023 at 7:21 AM Shammon FY <zjur...@gmail.com> > > >>> wrote: > > >>>>>>>> > > >>>>>>>>> Hi kui > > >>>>>>>>> > > >>>>>>>>> Thanks for your answer and +1 to yuxia too > > >>>>>>>>> > > >>>>>>>>>> we should not bind the watermark-related options to a > connector > > >>> to > > >>>>>>>> ensure > > >>>>>>>>> semantic clarity. > > >>>>>>>>> > > >>>>>>>>> In my opinion, adding watermark-related options to a connector > is > > >>>>> much > > >>>>>>>> more > > >>>>>>>>> clear. Currently users can define simple watermark strategy in > > >>> DDL, > > >>>>>>>> adding > > >>>>>>>>> more configuration items in connector options is easy to > > >>> understand > > >>>>>>>>> > > >>>>>>>>> Best, > > >>>>>>>>> Shammon > > >>>>>>>>> > > >>>>>>>>> > > >>>>>>>>> On Thu, Feb 23, 2023 at 10:52 AM Jingsong Li < > > >>> jingsongl...@gmail.com > > >>>>>> > > >>>>>>>>> wrote: > > >>>>>>>>> > > >>>>>>>>>> Thanks for your proposal. > > >>>>>>>>>> > > >>>>>>>>>> +1 to yuxia, consider watermark-related hints as option hints. > > >>>>>>>>>> > > >>>>>>>>>> Personally, I am cautious about adding SQL syntax, > > >>> WATERMARK_PARAMS > > >>>>> is > > >>>>>>>>>> also SQL syntax to some extent. > > >>>>>>>>>> > > >>>>>>>>>> We can use OPTIONS to meet this requirement if possible. > > >>>>>>>>>> > > >>>>>>>>>> Best, > > >>>>>>>>>> Jingsong > > >>>>>>>>>> > > >>>>>>>>>> On Thu, Feb 23, 2023 at 10:41 AM yuxia < > > >>> luoyu...@alumni.sjtu.edu.cn > > >>>>>> > > >>>>>>>>>> wrote: > > >>>>>>>>>>> > > >>>>>>>>>>> Hi, Yuan Kui. > > >>>>>>>>>>> Thanks for driving it. > > >>>>>>>>>>> IMO, the 'OPTIONS' hint may be not only specific to the > > >>> connector > > >>>>>>>>>> options. Just as a reference, we also have > `sink.parallelism`[1] > > >>> as > > >>>>> a > > >>>>>>>>>> connector options. It enables > > >>>>>>>>>>> user to specific the writer's parallelism dynamically > > per-query. > > >>>>>>>>>>> > > >>>>>>>>>>> Personally, I perfer to consider watermark-related hints as > > >>> option > > >>>>>>>>>> hints. So, user can define a default watermark strategy for > the > > >>>>> table, > > >>>>>>>>> and > > >>>>>>>>>> if user dosen't needed to changes it, they need to do nothing > in > > >>>>> their > > >>>>>>>>>> query instead of specific it ervery time. > > >>>>>>>>>>> > > >>>>>>>>>>> [1] > > >>>>>>>>>> > > >>>>>>>>> > > >>>>>>>> > > >>>>> > > >>> > > > https://nightlies.apache.org/flink/flink-docs-master/zh/docs/connectors/table/filesystem/#sink-parallelism > > >>>>>>>>>>> > > >>>>>>>>>>> Best regards, > > >>>>>>>>>>> Yuxia > > >>>>>>>>>>> > > >>>>>>>>>>> Best regards, > > >>>>>>>>>>> Yuxia > > >>>>>>>>>>> > > >>>>>>>>>>> ----- 原始邮件 ----- > > >>>>>>>>>>> 发件人: "kui yuan" <catye...@gmail.com> > > >>>>>>>>>>> 收件人: "dev" <dev@flink.apache.org> > > >>>>>>>>>>> 抄送: "Jark Wu" <imj...@gmail.com> > > >>>>>>>>>>> 发送时间: 星期三, 2023年 2 月 22日 下午 10:08:11 > > >>>>>>>>>>> 主题: Re: [DISCUSS] FLIP-296: Watermark options for table API & > > >>> SQL > > >>>>>>>>>>> > > >>>>>>>>>>> Hi all, > > >>>>>>>>>>> > > >>>>>>>>>>> Thanks for the lively discussion and I will respond to these > > >>>>>>>> questions > > >>>>>>>>>> one > > >>>>>>>>>>> by one. However, there are also some common questions and I > > will > > >>>>>>>> answer > > >>>>>>>>>>> together. > > >>>>>>>>>>> > > >>>>>>>>>>> @郑 Thanks for your reply. The features mentioned in this flip > > >>> are > > >>>>>>>> only > > >>>>>>>>>> for > > >>>>>>>>>>> those source connectors that implement the > > >>>>> SupportsWatermarkPushDown > > >>>>>>>>>>> interface, generating watermarks in other graph locations is > > >>> not in > > >>>>>>>> the > > >>>>>>>>>>> scope of this discussion. Perhaps another flip can be > proposed > > >>>>>>>> later to > > >>>>>>>>>>> implement this feature. > > >>>>>>>>>>> > > >>>>>>>>>>> @Shammon Thanks for your reply. In Flip-296, a rejected > > >>> alternative > > >>>>>>>> is > > >>>>>>>>>>> adding watermark related options in the connector options，we > > >>>>> believe > > >>>>>>>>> that > > >>>>>>>>>>> we should not bind the watermark-related options to a > connector > > >>> to > > >>>>>>>>> ensure > > >>>>>>>>>>> semantic clarity. > > >>>>>>>>>>> > > >>>>>>>>>>>> What will happen if we add watermark related options in `the > > >>>>>>>>> connector > > >>>>>>>>>>>> options`? Will the connector ignore these options or throw > an > > >>>>>>>>>> exception? > > >>>>>>>>>>>> How can we support this? > > >>>>>>>>>>> > > >>>>>>>>>>> If user defines different watermark configurations for one > > >>> table in > > >>>>>>>> two > > >>>>>>>>>>> places, I tend to prefer the first place would prevail, but > we > > >>> can > > >>>>>>>>> also > > >>>>>>>>>>> throw exception or just print logs to prompt the user, which > > are > > >>>>>>>>>>> implementation details. > > >>>>>>>>>>> > > >>>>>>>>>>>> If one table is used by two operators with different > watermark > > >>>>>>>>> params, > > >>>>>>>>>>>> what will happen? > > >>>>>>>>>>> > > >>>>>>>>>>> @Martijn Thanks for your reply. I'm sorry that we are not > > >>>>>>>> particularly > > >>>>>>>>>>> accurate, this hint is mainly for SQL, not table API. > > >>>>>>>>>>> > > >>>>>>>>>>>> While the FLIP talks about watermark options for Table API & > > >>> SQL, > > >>>>>>>> I > > >>>>>>>>>> only > > >>>>>>>>>>>> see proposed syntax for SQL, not for the Table API. What is > > >>> your > > >>>>>>>>>> proposal > > >>>>>>>>>>>> for the Table API > > >>>>>>>>>>> > > >>>>>>>>>>> @Jane Thanks for your reply. For the first question, If the > > user > > >>>>>>>> uses > > >>>>>>>>>> this > > >>>>>>>>>>> hint on those sourse that does not implement the > > >>>>>>>>>> SupportsWatermarkPushDown > > >>>>>>>>>>> interface, it will be completely invalid. The task will run > as > > >>>>>>>> normal > > >>>>>>>>> as > > >>>>>>>>>> if > > >>>>>>>>>>> the hint had not been used. > > >>>>>>>>>>> > > >>>>>>>>>>>> What's the behavior if there are multiple table sources, > among > > >>>>>>>> which > > >>>>>>>>>>>> some do not support `SupportsWatermarkPushDown`? > > >>>>>>>>>>> > > >>>>>>>>>>> @Jane feedback that 'WATERMARK_PARAMS' is difficult to > > remember, > > >>>>>>>>> perhaps > > >>>>>>>>>>> the naming issue can be put to the end of the discussion, > > >>> because > > >>>>>>>> more > > >>>>>>>>>>> people like @Martijn @Shuo are considering whether these > > >>>>>>>> configurations > > >>>>>>>>>>> should be put into the DDL or the 'OPTIONS' hint. Here's > what I > > >>>>>>>>>>> think, Putting these configs into DDL or putting them into > > >>>>> 'OPTIONS' > > >>>>>>>>> hint > > >>>>>>>>>>> is actually the same thing, because the 'OPTIONS' hint is > > mainly > > >>>>>>>> used > > >>>>>>>>> to > > >>>>>>>>>>> configure the properties of conenctor. The reason why I want > to > > >>> use > > >>>>>>>> a > > >>>>>>>>> new > > >>>>>>>>>>> hint is to make sure the semantics clear, in my opinion the > > >>>>>>>>> configuration > > >>>>>>>>>>> of watermark should not be mixed up with connector. However, > a > > >>> new > > >>>>>>>> hint > > >>>>>>>>>>> does make it more difficult to use to some extent, for > example, > > >>>>>>>> when a > > >>>>>>>>>> user > > >>>>>>>>>>> uses both 'OPTIONS' hint and 'WATERMARK_PARAMS' hint. For > this > > >>>>>>>> point, > > >>>>>>>>>> maby > > >>>>>>>>>>> it is more appropriate to use uniform 'OPTIONS' hint. > > >>>>>>>>>>> On the other hand, if we enrich more watermark option keys in > > >>>>>>>> 'OPTIONS' > > >>>>>>>>>>> hints, The question will be what we treat the definatrions of > > >>>>>>>>> 'OPTIONS' > > >>>>>>>>>>> hint, is this only specific to the connector options or could > > be > > >>>>>>>> more? > > >>>>>>>>>>> Maybe @Jark could share more insights here. In my opion, > > >>> 'OPTIONS' > > >>>>>>>> is > > >>>>>>>>>> only > > >>>>>>>>>>> related to the connector options, which is not like the > gernal > > >>>>>>>>> watermark > > >>>>>>>>>>> options. > > >>>>>>>>>>> > > >>>>>>>>>>> > > >>>>>>>>>>> > > >>>>>>>>>>> Shuo Cheng <njucs...@gmail.com> 于2023年2月22日周三 19:17写道： > > >>>>>>>>>>> > > >>>>>>>>>>>> Hi Kui, > > >>>>>>>>>>>> > > >>>>>>>>>>>> Thanks for driving the discussion. It's quite useful to > > >>> introduce > > >>>>>>>>>> Watermark > > >>>>>>>>>>>> options. I have some questions: > > >>>>>>>>>>>> > > >>>>>>>>>>>> What kind of hints is "WATERMARK_PARAMS"? > > >>>>>>>>>>>> Currently, we have two kinds of hints in Flink: Dynamic > Table > > >>>>>>>>> Options & > > >>>>>>>>>>>> Query Hints. As described in the Flip, "WATERMARK_PARAMS" is > > >>> more > > >>>>>>>>> like > > >>>>>>>>>>>> Dynamic Table Options. So two questions arise here: > > >>>>>>>>>>>> > > >>>>>>>>>>>> 1) Are these watermark options to be exposed as connector > > WITH > > >>>>>>>>>> options? Aa > > >>>>>>>>>>>> described in SQL Hints doc[1], "Dynamic Table Options allow > > to > > >>>>>>>>>> specify or > > >>>>>>>>>>>> override table options dynamically", which implies that > these > > >>>>>>>> options > > >>>>>>>>>> can > > >>>>>>>>>>>> also be configured in WITH options. > > >>>>>>>>>>>> > > >>>>>>>>>>>> 2) Do we really need a new hint name like > 'WATERMARK_PARAMS', > > >>>>>>>> table > > >>>>>>>>>>>> options use "OPTIONS" as hint name, like '/*+ > > >>>>>>>>>>>> OPTIONS('csv.ignore-parse-errors'='true') */', maybe we can > > >>> enrich > > >>>>>>>>> more > > >>>>>>>>>>>> table option keys for watermark, e.g., /*+ > > >>>>>>>>>>>> OPTIONS('watermark.emit-strategy'='ON_PERIODIC') */. > > >>>>>>>>>>>> > > >>>>>>>>>>>> > > >>>>>>>>>>>> [1] > > >>>>>>>>>>>> > > >>>>>>>>>>>> > > >>>>>>>>>> > > >>>>>>>>> > > >>>>>>>> > > >>>>> > > >>> > > > https://nightlies.apache.org/flink/flink-docs-release-1.16/docs/dev/table/sql/queries/hints/ > > >>>>>>>>>>>> > > >>>>>>>>>>>> On Wed, Feb 22, 2023 at 10:22 AM kui yuan < > catye...@gmail.com > > > > > >>>>>>>>> wrote: > > >>>>>>>>>>>> > > >>>>>>>>>>>>> Hi devs, > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> I'd like to start a discussion thread for FLIP-296[1]. This > > >>>>>>>> comes > > >>>>>>>>>> from an > > >>>>>>>>>>>>> offline discussion with @Yun Tang, and we hope to enrich > > table > > >>>>>>>> API > > >>>>>>>>> & > > >>>>>>>>>> SQL > > >>>>>>>>>>>> to > > >>>>>>>>>>>>> support many watermark-related features which were only > > >>>>>>>> implemented > > >>>>>>>>>> at > > >>>>>>>>>>>> the > > >>>>>>>>>>>>> datastream API level. > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> Basically, we want to introduce watermark options in table > > >>> API & > > >>>>>>>>> SQL > > >>>>>>>>>> via > > >>>>>>>>>>>>> SQL hint named 'WATERMARK_PARAMS' to support features: > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> 1、Configurable watermark emit strategy > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> 2、Dealing with idle sources > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> 3、Watermark alignment > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> Last but not least, thanks to Qingsheng and Jing Zhang for > > the > > >>>>>>>>>> initial > > >>>>>>>>>>>>> reviews. > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> Looking forward to your thoughts and any feedback is > > >>>>>>>> appreciated! > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> [1] > > >>>>>>>>>>>>> > > >>>>>>>>>>>> > > >>>>>>>>>> > > >>>>>>>>> > > >>>>>>>> > > >>>>> > > >>> > > > https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=240884405 > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> Best > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> Yuan Kui > > >>>>>>>>>>>>> > > >>>>>>>>>>>> > > >>>>>>>>>> > > >>>>>>>>> > > >>>>>>>> > > >>>>>>> > > >>>>>> > > >>>>> > > >>>>> > > >>> > > >> > > > > > > > >
