Hello Nikolay, Thanks for picking this up! Just sharing my two cents:
1) I'd suggest keeping `Punctuator#punctuate(long timestamp)` as is since comparing with other places where we are replacing with Duration and Instant, this is not a user specified value as part of the DSL but rather a passed-in parameter, plus with high punctuation frequency creating a new instance of Instant may be costly. 2) I'm fine with keeping KeyValueStore extending ReadOnlyKeyValueStore with APIs of `long` as well as inheriting APIs of `Duration`. Guozhang On Mon, Sep 10, 2018 at 11:11 AM, Nikolay Izhikov <nizhi...@apache.org> wrote: > Hello, Matthias. > > > (4) While I agree that we might want to deprecate it, I am not sure if > this should be part of this KIP? > > Seems to be unrelated? > > Should this have been part of KIP-319? > > If yes, we might still want to updated this other KIP? WDYT? > > OK, I removed this deprecation from this KIP. > > Please, tell me, is there anything else that should be improved to make > this KIP ready to be implemented. > > В Пт, 07/09/2018 в 17:06 -0700, Matthias J. Sax пишет: > > (1) Sounds good to me, to just use IllegalArgumentException for both -- > > and thanks for pointing out that Duration can be negative and we need to > > check for this. For the KIP, it would be nice to add to all methods than > > (even if we don't do it in the code but only document in JavaDocs). > > > > (2) I would argue for a new single method interface. Not sure about the > > name though. > > > > (3) Even if `#fetch(K, K, long, long)` and `#fetchAll(long, long)` is > > _currently_ not used internally, I would still argue they are both dual > > use -- we might all a new DSL operator at any point that uses those > > methods. Thus to be "future prove" I would consider them dual use. > > > > > Since the ReadOnlyWindowStore is only used by IQ, > > > > This contradicts your other statement: > > > > > org.apache.kafka.streams.state.ReadOnlyWindowStore#fetch(K, long) is > used > > > in KStreamWindowAggregate. > > > > Or do you suggest to move `fetch(K, long)` from `ReadOnlyWindowStore` to > > `WindowStore` ? This would not make sense IMHO, as `WindowStore extends > > ReadOnlyWindowStore` and thus, we would loose this method for IQ. > > > > > > (4) While I agree that we might want to deprecate it, I am not sure if > > this should be part of this KIP? Seems to be unrelated? Should this have > > been part of KIP-319? If yes, we might still want to updated this other > > KIP? WDYT? > > > > > > -Matthias > > > > > > On 9/7/18 12:09 PM, John Roesler wrote: > > > Hey all, > > > > > > (1): Duration can be negative, just like long. We need to enforce any > > > bounds that we currently enforce. We don't need the `throws` > declaration > > > for runtime exceptions, but the potential IllegalArgumentException > should > > > be documented in the javadoc for these methods. I still feel that > surfacing > > > the ArithmeticException directly would not be a great experience, so I > > > still advocate for wrapping it in an IllegalArgumentException that > explains > > > our upper bound for Duration is "max-long number of milliseconds" > > > > > > (2): I agree with your performance intuition. I don't think creating > one > > > object per call to punctuate is going to substantially affect the > > > performance. > > > > > > I think the deeper problem with Punctuator is that it's currently a SAM > > > interface. If we add a new method to it, we break the source code of > anyone > > > passing a function. We can add the new method with a default > > > implementation, as Nikolay suggested, but then you get into figuring > out > > > which one to default, and no one's happy. Alternatively, we can just > make a > > > brand new interface that is still a single method (but an Instant) and > add > > > the appropriate overloads and deprecate the old ones. > > > > > > (3): I disagree. I think only two methods are dual use, and we should > > > separate the internal from external usages. The internal usage should > be > > > added to WindowStore. > > > org.apache.kafka.streams.state.ReadOnlyWindowStore#fetch(K, long) is > used > > > in KStreamWindowAggregate. > > > org.apache.kafka.streams.state.ReadOnlyWindowStore#fetch(K, long, > long) is > > > used in KStreamKStreamJoin. > > > Both of these usages are as WindowStore, so adding these interfaces to > > > WindowStore would be transparent. > > > > > > org.apache.kafka.streams.state.ReadOnlyWindowStore#fetch(K, K, long, > long) > > > is only used for IQ > > > org.apache.kafka.streams.state.ReadOnlyWindowStore#fetchAll(long, > long) is > > > only used for IQ > > > > > > Since the ReadOnlyWindowStore is only used by IQ, we can safely say > that > > > *all* of its methods are external use and can be deprecated and > replaced. > > > The first two usages I noted are WindowStore usages, not > > > ReadOnlyWindowStores, and WindowStore is only used *internally*, so > it's > > > free to offer `long` methods if needed for performance reasons. > > > > > > Does this make sense? The same reasoning extends to the other stores. > > > > > > (4) Yes, that was my suggestion. I'm not sure if anyone is actually > using > > > this variant, so it seemed like a good time to just deprecate it and > see. > > > > > > Thoughts? > > > -John > > > > > > > > > On Fri, Sep 7, 2018 at 10:21 AM Nikolay Izhikov <nizhi...@apache.org> > wrote: > > > > > > > Hello, Matthias. > > > > > > > > Thanks, for feedback. > > > > > > > > > (1) Some methods declare `throws IllegalArgumentException`, others> > > > > > > > > don't. > > > > > > > > `duration.toMillis()` can throw ArithmeticException. > > > > It can happen if overflow occurs during conversion. > > > > Please, see source of jdk method Duration#toMillis. > > > > Task author suggest to wrap it to IllegalArgumentException. > > > > I think we should add `throws IllegalArgumentException` for all > method > > > > with Duration parameter. > > > > (I updated KIP with this throws) > > > > > > > > What do you think? > > > > > > > > > (3) ReadOnlyWindowStore: All three methods are dual use and I > think we > > > > > > > > should not deprecate them. > > > > > > > > This is my typo, already fixed. > > > > I propose to add new methods to `ReadOnlyWindowStore`. > > > > No methods will become deprecated. > > > > > > > > > (4) Stores: 3 methods are listed as deprecated but only 2 new > methods > > > > > > > > are added. > > > > > > > > My proposal based on John Roesler mail [1]: > > > > "10. Stores: I think we can just deprecate without replacement the > method > > > > that takes `segmentInterval`." > > > > > > > > Is it wrong? > > > > > > > > [1] https://www.mail-archive.com/dev@kafka.apache.org/msg91348.html > > > > > > > > > > > > В Чт, 06/09/2018 в 21:04 -0700, Matthias J. Sax пишет: > > > > > Thanks for updating the KIP! > > > > > > > > > > Couple of minor follow ups: > > > > > > > > > > (1) Some methods declare `throws IllegalArgumentException`, others > > > > > don't. It's runtime exception and thus it's not required to > declare it > > > > > -- it just looks inconsistent in the KIP and maybe it's > inconsistent in > > > > > the code, too. I am not sure if it is possible to provide a > negative > > > > > Duration? If not, we would not need to check the provided value > and can > > > > > remove the declaration. > > > > > > > > > > (2) About punctuations: I still think, it would be ok to change the > > > > > callback from `long` to `Instance` -- even if it is possible to > register > > > > > a punctuation on a ms-basis, in practice many people used > schedules in > > > > > the range of seconds or larger. Thus, I don't think there will be a > > > > > performance penalty. Of course, we can still revisit this later, > too. > > > > > John and Bill, you did not comment on this. Would also be good to > get > > > > > feedback from Guozhang about this. > > > > > > > > > > (3) ReadOnlyWindowStore: All three methods are dual use and I > think we > > > > > should not deprecate them. However, we can add the new proposed > methods > > > > > in parallel -- the names can be the same without conflict as the > > > > > parameter lists are different. (Or did you just forget to remove > the > > > > > comment line?) > > > > > > > > > > (4) Stores: 3 methods are listed as deprecated but only 2 new > methods > > > > > are added. Maybe this was discussed already, but I can't recall > why? Can > > > > > you elaborate? Or should this deprecation be actually be part of > KIP-328 > > > > > (\cc John)? > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > -Matthias > > > > > > > > > > > > > > > > > > > > ps: there are many KIPs in-flight in parallel, and it takes some > time to > > > > > get around. Please be patient :) > > > > > > > > > > > > > > > > > > > > > > > > > On 9/5/18 12:25 AM, Nikolay Izhikov wrote: > > > > > > Hello, Guys. > > > > > > > > > > > > I've started a VOTE [1], but seems commiters have no chance to > look at > > > > > > > > KIP for now. > > > > > > > > > > > > Can you tell me, is it OK? > > > > > > Should I wait for feedback? For how long? > > > > > > > > > > > > Or something in KIP should be improved before voting? > > > > > > > > > > > > [1] > > > > > > > > https://lists.apache.org/thread.html/e976352e7e42d459091ee66ac790b6 > a0de7064eac0c57760d50c983b@%3Cdev.kafka.apache.org%3E > > > > > > > > > > > > В Пт, 24/08/2018 в 10:36 -0700, Matthias J. Sax пишет: > > > > > > > It's tricky... :) > > > > > > > > > > > > > > Some APIs have "dual use" as I mentioned in my first reply. I > agree > > > > > > > > that > > > > > > > it would be good to avoid abstract class and use interfaces if > > > > > > > > possible. > > > > > > > As long as the change is source code compatible, it should be > fine > > > > > > > > IMHO > > > > > > > -- we need to document binary incompatibility of course. > > > > > > > > > > > > > > I think it's best, if the KIPs gets update with a proposal on > how to > > > > > > > handle "dual use" parts. It's easier to discuss if it's > written down > > > > > > > > IMHO. > > > > > > > > > > > > > > For `ProcessorContext#schedule()`, you are right John: it's > seems > > > > > > > > fine > > > > > > > to use `Duration`, as it won't be called often (usually only > within > > > > > > > `Processor#init()`) -- I mixed it up with > > > > > > > > `Punctuator#punctuate(long)`. > > > > > > > However, thinking about this twice, we might even want to > update both > > > > > > > methods. Punctuation callbacks don't happen every millisecond > and > > > > > > > > thus > > > > > > > the overhead to use `Instance` should not be a problem. > > > > > > > > > > > > > > @Nikolay: it seems the KIP does not mention > > > > > > > > `Punctuator#punctuate(long)` > > > > > > > -- should we add it? > > > > > > > > > > > > > > > > > > > > > -Matthias > > > > > > > > > > > > > > > > > > > > > On 8/24/18 10:11 AM, John Roesler wrote: > > > > > > > > Quick afterthought: I guess that `Window` is exposed to the > API via > > > > > > > > `Windowed` keys. I think it would be fine to not deprecate > the > > > > > > > > `long` start > > > > > > > > and end, but add `Instant` variants for people preferring > that > > > > > > > > interface. > > > > > > > > > > > > > > > > On Fri, Aug 24, 2018 at 11:10 AM John Roesler < > j...@confluent.io> > > > > > > > > wrote: > > > > > > > > > > > > > > > > > Hey Matthias, > > > > > > > > > > > > > > > > > > Thanks for pointing that out. I agree that we only really > need > > > > > > > > to change > > > > > > > > > methods that are API-facing, and we probably want to avoid > using > > > > > > > > > Duration/Instant for Streams-facing members. > > > > > > > > > > > > > > > > > > Like I said in my last email, I think the whole Windows > > > > > > > > interface is > > > > > > > > > Streams-facing, and the builders we provide are otherwise > > > > > > > > API-facing. > > > > > > > > > Likewise, `Window` is Streams-facing, so start and end > should > > > > > > > > not use > > > > > > > > > Duration. In SessionWindows, inactivityGap is > Streams-facing. > > > > > > > > > > > > > > > > > > I actually think that ProcessorContext#schedule() is > API-facing, > > > > > > > > so it > > > > > > > > > should use Duration. The rationale is that streams > processing > > > > > > > > doesn't call > > > > > > > > > this method, only implementer of Processor do. Does that > seem > > > > > > > > right? > > > > > > > > > > > > > > > > > > Also, it seems like ReadOnlyWindowStore#fetch() (2x) and > > > > > > > > #fetchAll() are > > > > > > > > > API-facing (for IQ). When we call fetch() during > processing, > > > > > > > > it's actually > > > > > > > > > `WindowStore#fetch()`. Maybe we should move > > > > > > > > "WindowStoreIterator<V> fetch(K > > > > > > > > > key, long timeFrom, long timeTo)" to the WindowStore > interface > > > > > > > > and make > > > > > > > > > all the ReadOnlyWindowStore methods take Durations. And > likewise > > > > > > > > with the > > > > > > > > > SessionStore interfaces. > > > > > > > > > > > > > > > > > > What do you think? > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > -John > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Fri, Aug 24, 2018 at 10:51 AM John Roesler < > j...@confluent.io> > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > Hi Nikolay, > > > > > > > > > > > > > > > > > > > > First: I wanted to let you know that we have dropped the > > > > > > > > `grace(long)` > > > > > > > > > > method from the Windows interface, but we do still need > to > > > > > > > > transition the > > > > > > > > > > same method on TimeWindows and JoinWindows ( > > > > > > > > > > https://github.com/apache/kafka/pull/5536) > > > > > > > > > > > > > > > > > > > > I have also been thinking it would be nice to replace > > > > > > > > `Windows` with an > > > > > > > > > > interface, but for different reasons. I think we can > even do > > > > > > > > it without > > > > > > > > > > breaking source compatibility (but it would break binary > > > > > > > > compatibility): > > > > > > > > > > create a new interface `WindowSpec`, deprecate `Windows` > and > > > > > > > > make it > > > > > > > > > > implement `WindowSpec`, add a new method: > > > > > > > > > > `KGroupedStream#windowedBy(WindowSpec)`, and deprecate > the old > > > > > > > > one. > > > > > > > > > > > > > > > > > > > > However, I don't think this would solve your problem, > since > > > > > > > > the Windows > > > > > > > > > > interface has two audiences: the DSL user and the > implementer > > > > > > > > who wishes to > > > > > > > > > > provide a new kind of windowing. I think we want to > provide > > > > > > > > Duration to the > > > > > > > > > > former, and long or Duration is fine for the latter. > However, > > > > > > > > both of these > > > > > > > > > > audiences are "external", so having an "internal" > interface > > > > > > > > won't fit the > > > > > > > > > > bill. > > > > > > > > > > > > > > > > > > > > I think my last PR #5536 actually helps the situation > quite a > > > > > > > > bit. Let's > > > > > > > > > > forget about the deprecated members. Now, all the public > > > > > > > > members of Windows > > > > > > > > > > are abstract methods, so Windows is effectively an > interface > > > > > > > > now. Here's > > > > > > > > > > how it looks: > > > > > > > > > > > > > > > > > > > > public abstract class Windows<W extends Window> { > > > > > > > > > > public abstract Map<Long, W> windowsFor(final long > timestamp); > > > > > > > > > > public abstract long size(); > > > > > > > > > > public abstract long gracePeriodMs(); > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > Notice that there is no part of this involved with the > DSL. > > > > > > > > When you're > > > > > > > > > > writing a topology, you don't call any of these methods. > It's > > > > > > > > strictly an > > > > > > > > > > interface that tells a Windows implementation what > Streams > > > > > > > > expects from it. > > > > > > > > > > A very simple implementation could have no builder > methods at > > > > > > > > all and just > > > > > > > > > > return fixed answers to these method calls (this is > basically > > > > > > > > what > > > > > > > > > > UnlimitedWindows does). It seems like, if we want to use > long > > > > > > > > millis > > > > > > > > > > internally, then we just need to leave Windows alone. > > > > > > > > > > > > > > > > > > > > What we do want to change is the builder methods in > > > > > > > > TimeWindows, > > > > > > > > > > JoinWindows, and UnlimitedWindows. For example, > > > > > > > > `TimeWindows#of(long)` > > > > > > > > > > would become `TimeWindows#of(Duration)`, etc. These are > the > > > > > > > > DSL methods. > > > > > > > > > > > > > > > > > > > > Does that make sense? > > > > > > > > > > -John > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Thu, Aug 23, 2018 at 8:59 AM Nikolay Izhikov < > > > > > > > > nizhi...@apache.org> > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > Hello, Mathias. > > > > > > > > > > > > > > > > > > > > > > Thanks for your feedback. > > > > > > > > > > > > > > > > > > > > > > > Thus, it might make sense to keep old and just add > new > > > > > > > > ones? > > > > > > > > > > > > > > > > > > > > > > As far as I understand, we will keep old methods > anyway to > > > > > > > > prevent > > > > > > > > > > > public API backward compatibility. > > > > > > > > > > > I agree with you, methods that used internally > shouldn't be > > > > > > > > deprecated. > > > > > > > > > > > > > > > > > > > > > > > End users can use the "nicer" new ones, while we can > still > > > > > > > > use the > > > > > > > > > > > > > > > > > > > > > > existing ones internally? > > > > > > > > > > > > Not sure if it would be possible to keep the old ones > > > > > > > > without exposing > > > > > > > > > > > > > > > > > > > > > > them as public API? > > > > > > > > > > > > > > > > > > > > > > I think, when we decide to remove methods with `long` > from > > > > > > > > public API, > > > > > > > > > > > we can do the following: > > > > > > > > > > > > > > > > > > > > > > 1. Create an interface like `WindowsInternal`. > > > > > > > > > > > 2. Change Windows to an interface. > > > > > > > > > > > 3. Create package-private implementation `WindowsImpl`. > > > > > > > > > > > > > > > > > > > > > > ``` > > > > > > > > > > > package org.apache.kafka.streams. > kstream.internals; > > > > > > > > > > > public interface WindowsInternal { > > > > > > > > > > > public long start(); > > > > > > > > > > > public long end(); > > > > > > > > > > > //etc... > > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > package org.apache.kafka.streams.kstream; > > > > > > > > > > > public interface Windows<W extends Window> { > > > > > > > > > > > public Instant start(); > > > > > > > > > > > public Instant end(); > > > > > > > > > > > //... > > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > class WindowsImpl<W extends Window> implements > > > > > > > > Windows<W>, > > > > > > > > > > > WindowsInternal { > > > > > > > > > > > > > > > > > > > > > > } > > > > > > > > > > > ``` > > > > > > > > > > > > > > > > > > > > > > So, in public API we will expose only `Windows` > interface > > > > > > > > and internally > > > > > > > > > > > we can use `WindowsInternal` > > > > > > > > > > > But, of course, this will be huge changes in public > API. > > > > > > > > > > > > > > > > > > > > > > > Let me know what you think about this. > > > > > > > > > > > > > > > > > > > > > > I think in this KIP we shouldn't deprecate methods, > that are > > > > > > > > used > > > > > > > > > > > internally. > > > > > > > > > > > I changed it, now my proposal is just add new methods. > > > > > > > > > > > > > > > > > > > > > > Please, let me know if anything more need to be done. > > > > > > > > > > > > > > > > > > > > > > В Ср, 22/08/2018 в 17:29 -0700, Matthias J. Sax пишет: > > > > > > > > > > > > Thanks a lot for the KIP. > > > > > > > > > > > > > > > > > > > > > > > > From my understanding, the idea of the KIP is to > improve > > > > > > > > the public API > > > > > > > > > > > > at DSL level. However, not all public methods listed > are > > > > > > > > part of DSL > > > > > > > > > > > > level API, but part of runtime API. Those methods are > > > > > > > > called during > > > > > > > > > > > > processing and are on the hot code path. I am not > sure, if > > > > > > > > we want to > > > > > > > > > > > > update those methods. We should carefully think about > > > > > > > > this, and > > > > > > > > > > > > > > > > > > > > > > consider > > > > > > > > > > > > to keep Long/long type to keep runtime overhead > small. > > > > > > > > Note, that the > > > > > > > > > > > > methods I mention are not required to specify a > program > > > > > > > > using the DSL > > > > > > > > > > > > and thus is questionable if the DSL API would be > improved > > > > > > > > if we change > > > > > > > > > > > > the methods. > > > > > > > > > > > > > > > > > > > > > > > > It's unfortunate, that some part of the public API > stretch > > > > > > > > the DSL > > > > > > > > > > > > builder part as well as the runtime part... > > > > > > > > > > > > > > > > > > > > > > > > This affects the following methods (please double > check if > > > > > > > > I missed > > > > > > > > > > > > > > > > > > > > > > any): > > > > > > > > > > > > > > > > > > > > > > > > - Windows#windowsFor() > > > > > > > > > > > > - Window#start() > > > > > > > > > > > > - Window#end() > > > > > > > > > > > > - JoinWindows#windowFor() > > > > > > > > > > > > - SessionWindows#inactivitiyGap() > > > > > > > > > > > > - TimeWindows#windowFor() > > > > > > > > > > > > - UnlimitedWindows#windowFor() > > > > > > > > > > > > - ProcessorContext#schedule() > > > > > > > > > > > > - ReadOnlyWindowStore#fetch() (2x) and #fetchAll() > > > > > > > > > > > > - SessionStore#findSessions() (2x) > > > > > > > > > > > > > > > > > > > > > > > > maybe > > > > > > > > > > > > - TimeWindowedDeserializer#getWindowSize() (it's > unused > > > > > > > > atm, but I > > > > > > > > > > > > could imagine that it might be use on the hot code > path in > > > > > > > > the furture) > > > > > > > > > > > > > > > > > > > > > > > > So methods have "dual" use and might be called > externally > > > > > > > > and > > > > > > > > > > > > > > > > > > > > > > internally: > > > > > > > > > > > > > > > > > > > > > > > > - Window#start() > > > > > > > > > > > > - Window#end() > > > > > > > > > > > > - ReadOnlyWindowStore#fetch() (2x) and #fetchAll() > > > > > > > > > > > > - SessionStore#findSessions() (2x) > > > > > > > > > > > > > > > > > > > > > > > > Thus, it might make sense to keep old and just add > new > > > > > > > > ones? End users > > > > > > > > > > > > can use the "nicer" new ones, while we can still use > the > > > > > > > > existing ones > > > > > > > > > > > > internally? Not sure if it would be possible to keep > the > > > > > > > > old ones > > > > > > > > > > > > without exposing them as public API? > > > > > > > > > > > > > > > > > > > > > > > > Let me know what you think about this. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -Matthias > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On 8/21/18 11:41 PM, Nikolay Izhikov wrote: > > > > > > > > > > > > > Dear, commiters. > > > > > > > > > > > > > > > > > > > > > > > > > > Please, pay attention to this KIP and share your > opinion. > > > > > > > > > > > > > > > > > > > > > > > > > > В Вт, 21/08/2018 в 11:14 -0500, John Roesler пишет: > > > > > > > > > > > > > > I'll solicit more reviews. Let's get at least one > > > > > > > > committer to > > > > > > > > > > > > > > > > > > > > > > chime in > > > > > > > > > > > > > > before we start a vote (since we need their > approval > > > > > > > > anyway). > > > > > > > > > > > > > > -John > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Mon, Aug 20, 2018 at 12:39 PM Nikolay Izhikov > < > > > > > > > > > > > > > > > > > > > > > > nizhi...@apache.org> > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hello, Ted. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks for the comment. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I've edit KIP and change proposal to > `windowSize`. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Guys, any other comments? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > В Вс, 19/08/2018 в 14:57 -0700, Ted Yu пишет: > > > > > > > > > > > > > > > > bq. // or just Duration windowSize(); > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > +1 to the above choice. > > > > > > > > > > > > > > > > The duration is obvious from the return > type. For > > > > > > > > getter > > > > > > > > > > > > > > > > > > > > > > methods, we > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > don't > > > > > > > > > > > > > > > > use get as prefix (as least for new code). > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Cheers > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Sun, Aug 19, 2018 at 8:03 AM Nikolay > Izhikov < > > > > > > > > > > > > > > > > > > > > > > nizhi...@apache.org> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hello, John. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Thank you very much for your feedback! > > > > > > > > > > > > > > > > > I've addressed all your comments. > > > > > > > > > > > > > > > > > Please, see my answers and let my know is > > > > > > > > anything in KIP > > > > > > > > > > > > > > > > > > > > > > [1] needs to > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > be > > > > > > > > > > > > > > > > > improved. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > The correct choice is actually > "Instant", not> > > > > > > > > > > > > > > > > > > > > > > "LocalDateTime" > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I've changed the methods proposed in KIP > [1] to > > > > > > > > use Instant. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I noticed some recent APIs are> missing > (see > > > > > > > > KIP-328) > > > > > > > > > > > > > > > > > > those APIs were just added and have > never been > > > > > > > > released... > > > > > > > > > > > > > > > > > > > > > > you can > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > just > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > replace them. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I've added new methods to KIP [1]. > > > > > > > > > > > > > > > > > Not released methods marked for remove. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > any existing method that's already > deprecated, > > > > > > > > don't bother > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > transitioning it to Duration. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Fixed. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > IllegalArgumentException... we should > plan to > > > > > > > > mention this > > > > > > > > > > > > > > > > > > > > > > in the > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > javadoc for those methods. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Got it. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > In Stores, windowSize and segmentInterval > > > > > > > > should also be > > > > > > > > > > > > > > > > > > > > > > durations. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Fixed. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > StreamsMetrics, recordLatency ... this > one is > > > > > > > > better left > > > > > > > > > > > > > > > > > > > > > > alone. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > OK. I removed this method from KIP [1]. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Two more questions question about > implementation: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 1. We have serveral methods without > parameters. > > > > > > > > > > > > > > > > > In java we can't have two methods with > > > > > > > > parameters with the > > > > > > > > > > > > > > > > > > > > > > same name. > > > > > > > > > > > > > > > > > It wouldn't compile. > > > > > > > > > > > > > > > > > So we have to rename new methods. Please, > see > > > > > > > > suggested > > > > > > > > > > > > > > > > > > > > > > names and share > > > > > > > > > > > > > > > > > your thoughts: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Windows { > > > > > > > > > > > > > > > > > long size() -> Duration windowSize(); > > > > > > > > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Window { > > > > > > > > > > > > > > > > > long start() -> Instant startTime(); > > > > > > > > > > > > > > > > > long end() -> Instant endTime(); > > > > > > > > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > SessionWindows { > > > > > > > > > > > > > > > > > long inactivityGap() -> Duration > > > > > > > > inactivityGapDuration(); > > > > > > > > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > TimeWindowedDeserializer { > > > > > > > > > > > > > > > > > Long getWindowSize() -> Duration > > > > > > > > > > > > > > > > > > > > > > getWindowSizeDuration(); // or > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > just > > > > > > > > > > > > > > > > > Duration windowSize(); > > > > > > > > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > SessionBytesStoreSupplier { > > > > > > > > > > > > > > > > > long retentionPeriod() -> Duration > > > > > > > > > > > > > > > > > > > > > > retentionPeriodDuration(); > > > > > > > > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > WindowBytesStoreSupplier { > > > > > > > > > > > > > > > > > long windowSize() -> Duration > > > > > > > > windowSizeDuration(); > > > > > > > > > > > > > > > > > long retentionPeriod() -> Duration > > > > > > > > > > > > > > > > > > > > > > retentionPeriodDuration(); > > > > > > > > > > > > > > > > > } > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 2. Do we want to use Duration and Instant > inside > > > > > > > > API > > > > > > > > > > > > > > > > > > > > > > implementations? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > IGNITE-7277: "Durations potentially worsen > > > > > > > > memory pressure > > > > > > > > > > > > > > > > > > > > > > and gc > > > > > > > > > > > > > > > > > performance, so internally, we will still > use > > > > > > > > longMs as the > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > representation." > > > > > > > > > > > > > > > > > IGNITE-7222: Duration used to store > retention. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > [1] > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP- > 358%3A+Migrate+Streams+API+to+Duration+instead+of+long+ms+times > > > > > > > > > > > > > > > > > [2] > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://github.com/apache/kafka/commit/ > b3771ba22acad7870e38ff7f58820c5b50946787#diff- > 47289575d3e3e2449f27b3a7b6788e1aR64 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > В Пт, 17/08/2018 в 14:46 -0500, John > Roesler > > > > > > > > пишет: > > > > > > > > > > > > > > > > > > Hi Nikolay, > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks for this very nice KIP! > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > To answer your questions: > > > > > > > > > > > > > > > > > > 1. Correct, we should not delete existing > > > > > > > > methods that > > > > > > > > > > > > > > > > > > > > > > have been > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > released, > > > > > > > > > > > > > > > > > > but ... > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 2. Yes, we should deprecate the 'long' > > > > > > > > variants so that we > > > > > > > > > > > > > > > > > > > > > > can drop > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > them > > > > > > > > > > > > > > > > > > later on. Personally, I like to mention > which > > > > > > > > version > > > > > > > > > > > > > > > > > > > > > > deprecated the > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > method > > > > > > > > > > > > > > > > > > so everyone can see later on how long > it's been > > > > > > > > > > > > > > > > > > > > > > deprecated, but this > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > may > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > be > > > > > > > > > > > > > > > > > > controversial, so let's let other weigh > in. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 3. I think you're asking whether it's > > > > > > > > appropriate to drop > > > > > > > > > > > > > > > > > > > > > > the "Ms" > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > suffix, > > > > > > > > > > > > > > > > > > and I think yes. So "long > inactivityGapMs" > > > > > > > > would become > > > > > > > > > > > > > > > > > > > > > > "Duration > > > > > > > > > > > > > > > > > > inactivityGap". > > > > > > > > > > > > > > > > > > In the places where the parameter's name > is > > > > > > > > just > > > > > > > > > > > > > > > > > > > > > > "duration", I think > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > we > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > can > > > > > > > > > > > > > > > > > > pick something more descriptive (I > realize it > > > > > > > > was already > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > "durationMs"; > > > > > > > > > > > > > > > > > > this is just a good time to improve it). > > > > > > > > > > > > > > > > > > Also, you're correct that we shouldn't > use a > > > > > > > > Duration to > > > > > > > > > > > > > > > > > > > > > > represent a > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > moment > > > > > > > > > > > > > > > > > > in time, like "startTime". The correct > choice > > > > > > > > is actually > > > > > > > > > > > > > > > > > > > > > > "Instant", > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > not > > > > > > > > > > > > > > > > > > "LocalDateTime", though. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://stackoverflow.com/questions/32437550/whats-the- > difference-between-instant-and-localdatetime > > > > > > > > > > > > > > > > > > explains why. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I also had a few notes on the KIP itself: > > > > > > > > > > > > > > > > > > 4. You might want to pull trunk again. I > > > > > > > > noticed some > > > > > > > > > > > > > > > > > > > > > > recent APIs are > > > > > > > > > > > > > > > > > > missing (see KIP-328). > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 5. Speaking of KIP-328: those APIs were > just > > > > > > > > added and > > > > > > > > > > > > > > > > > > > > > > have never > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > been > > > > > > > > > > > > > > > > > > released, so there's no need to > deprecate the > > > > > > > > methods, you > > > > > > > > > > > > > > > > > > > > > > can just > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > replace > > > > > > > > > > > > > > > > > > them. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 6. For any existing method that's already > > > > > > > > deprecated, > > > > > > > > > > > > > > > > > > > > > > don't bother > > > > > > > > > > > > > > > > > > transitioning it to Duration. I think the > > > > > > > > examples I > > > > > > > > > > > > > > > > > > > > > > noticed were > > > > > > > > > > > > > > > > > > deprecated in KIP-328, so you'll see > what I'm > > > > > > > > talking > > > > > > > > > > > > > > > > > > > > > > about when you > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > pull > > > > > > > > > > > > > > > > > > trunk again. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 7. Any method taking a Duration argument > may > > > > > > > > throw an > > > > > > > > > > > > > > > > > > IllegalArgumentException (we choose to > convert > > > > > > > > > > > > > > > > > > > > > > ArithmeticException to > > > > > > > > > > > > > > > > > > IllegalArgumentException, as I mentioned > in > > > > > > > > the Jira > > > > > > > > > > > > > > > > > > > > > > ticket). We > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > don't > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > need > > > > > > > > > > > > > > > > > > a "throws" declaration, but we should > plan to > > > > > > > > mention this > > > > > > > > > > > > > > > > > > > > > > in the > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > javadoc > > > > > > > > > > > > > > > > > > for those methods. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 8. In Stores, windowSize and > segmentInterval > > > > > > > > should also be > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > durations. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 9. In StreamsMetrics, recordLatency > could be > > > > > > > > just a > > > > > > > > > > > > > > > > > > > > > > Duration, but I > > > > > > > > > > > > > > > > > > actually think this one is better left > alone. > > > > > > > > IMO, it's > > > > > > > > > > > > > > > > > > > > > > more effort > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > for > > > > > > > > > > > > > > > > > > little gain to require users to > construct a > > > > > > > > Duration > > > > > > > > > > > > > > > > > > > > > > before they > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > call the > > > > > > > > > > > > > > > > > > method, since they vary likely call > > > > > > > > > > > > > > > > > > > > > > System.currentTimeNanos before > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > and > > > > > > > > > > > > > > > > > > after the code in question. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > These are quite a few notes, but they're > all > > > > > > > > minor. > > > > > > > > > > > > > > > > > > > > > > Overall the KIP > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > looks > > > > > > > > > > > > > > > > > > really good to me. Thanks for picking > this up! > > > > > > > > > > > > > > > > > > -John > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > On Thu, Aug 16, 2018 at 9:55 AM Nikolay > > > > > > > > Izhikov < > > > > > > > > > > > > > > > > > > > > > > nizhi...@apache.org > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hello, Kafka developers. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I would like to start a discussion of > > > > > > > > KIP-358 [1]. > > > > > > > > > > > > > > > > > > > It based on a ticket KAFKA-7277 [2]. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I crawled through Stream API and made > my > > > > > > > > suggestions for > > > > > > > > > > > > > > > > > > > > > > API > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > changes. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I have several questions about changes. > > > > > > > > > > > > > > > > > > > Please, share your comments: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 1. I propose do not remove existing API > > > > > > > > methods with > > > > > > > > > > > > > > > > > > > > > > long ms > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > parameters. > > > > > > > > > > > > > > > > > > > Is it correct? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 2. Should we mark existing methods as > > > > > > > > deprecated? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > 3. Suggested changes in ticket > description > > > > > > > > are `long > > > > > > > > > > > > > > > > > > > > > > durationMs` to > > > > > > > > > > > > > > > > > > > `Duration duration` and similar. > > > > > > > > > > > > > > > > > > > I suggest to change 'long startTimeMs` > to > > > > > > > > `LocalDateTime > > > > > > > > > > > > > > > > > > > > > > startTime` > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > also. > > > > > > > > > > > > > > > > > > > Should we do it? > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Please, note, it very first KIP for > me, so > > > > > > > > tell me if I > > > > > > > > > > > > > > > > > > > > > > miss > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > something > > > > > > > > > > > > > > > > > > > obvious for experienced Kafka > developers. > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > [1] > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP- > 358%3A+Migrate+Streams+API+to+Duration+instead+of+long+ms+times > > > > > > > > > > > > > > > > > > > [2] > > > > > > > > https://issues.apache.org/jira/browse/KAFKA-7277 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- -- Guozhang
