Hi Aljoscha, Regarding your concern - to not expose the StreamRecord in the Evictor, were you able to find any alternative?
I tried to make the methods take Iterable<IN> input similar to the WindowFunction, but that didn't work since we have to clear the state and add the elements back to the state (to fix the bug mentioned in the previous mail) If you think the interface that accepts Iterable<StreamRecord<T>> elements is good enough, I have the changes ready. Thanks, Vishnu On Mon, Jul 25, 2016 at 7:48 AM, Aljoscha Krettek <aljos...@apache.org> wrote: > Hi, > the elements are currently not being removed from the buffers. That's a bug > that we could fix while adding the new Evictor interface. > > Cheers, > Aljoscha > > On Mon, 25 Jul 2016 at 13:00 Radu Tudoran <radu.tudo...@huawei.com> wrote: > > > Hi Aljoscha, > > > > Can you point us to the way it is handled now. Is there anything else for > > the removing of elements other than the skip in EvictingWindowOperator. > Is > > there something as it was before version 1.x where you had an explicit > > remove from window buffers? > > > > Dr. Radu Tudoran > > Research Engineer - Big Data Expert > > IT R&D Division > > > > > > HUAWEI TECHNOLOGIES Duesseldorf GmbH > > European Research Center > > Riesstrasse 25, 80992 München > > > > E-mail: radu.tudo...@huawei.com > > Mobile: +49 15209084330 > > Telephone: +49 891588344173 > > > > HUAWEI TECHNOLOGIES Duesseldorf GmbH > > Hansaallee 205, 40549 Düsseldorf, Germany, www.huawei.com > > Registered Office: Düsseldorf, Register Court Düsseldorf, HRB 56063, > > Managing Director: Bo PENG, Wanzhou MENG, Lifang CHEN > > Sitz der Gesellschaft: Düsseldorf, Amtsgericht Düsseldorf, HRB 56063, > > Geschäftsführer: Bo PENG, Wanzhou MENG, Lifang CHEN > > This e-mail and its attachments contain confidential information from > > HUAWEI, which is intended only for the person or entity whose address is > > listed above. Any use of the information contained herein in any way > > (including, but not limited to, total or partial disclosure, > reproduction, > > or dissemination) by persons other than the intended recipient(s) is > > prohibited. If you receive this e-mail in error, please notify the sender > > by phone or email immediately and delete it! > > > > > > -----Original Message----- > > From: Aljoscha Krettek [mailto:aljos...@apache.org] > > Sent: Monday, July 25, 2016 11:45 AM > > To: dev@flink.apache.org > > Subject: Re: [DISCUSS][FLIP-4] Enhance Window Evictor in Flink > > > > Hi, > > I think there is not yet a clear specification for how the actual removal > > of elements from the buffer will work. I think naively one can do: > > > > Iterable<E> currentElements = state.get() > > evictor.evict(currentElements); // this will remove some stuff from > there, > > or mark for removal > > > > state.clear() > > // the Iterable does not loop over the removed/marked elements > > for (E element : currentElements) { > > state.add(element) > > } > > > > This is very costly but the only way I see of doing this right now with > > every state backend. > > > > Cheers, > > Aljoscha > > > > On Mon, 25 Jul 2016 at 09:46 Radu Tudoran <radu.tudo...@huawei.com> > wrote: > > > > > Hi, > > > > > > Thanks for the clarification. Can someone point to where the events are > > > removed from buffers - I am trying to understand the new logic of > > handling > > > the eviction in this new API. Thanks > > > > > > > > > > > > -----Original Message----- > > > From: Vishnu Viswanath [mailto:vishnu.viswanat...@gmail.com] > > > Sent: Saturday, July 23, 2016 3:04 AM > > > To: Dev > > > Subject: Re: [DISCUSS][FLIP-4] Enhance Window Evictor in Flink > > > > > > Hi Radu, > > > > > > - Yes we can remove elements from the iterator. > > > - Right now the EvictingWindowOperator just skips the elements from the > > > Iterable before passing to the window function(Yes this has to be > changed > > > in the new API) > > > - Regarding how the last question on how elements are being removed > from > > > the window buffer. I am not sure how it is working right now, but when > > > trying out the new API that I am working on, I did find a bug where the > > > evicted elements are not actually removed from the State. I have added > a > > > fix for that. (You can see a mail regarding that in this mail chain) > > > > > > Thanks, > > > Vishnu > > > > > > On Fri, Jul 22, 2016 at 1:03 PM, Radu Tudoran <radu.tudo...@huawei.com > > > > > wrote: > > > > > > > Hi, > > > > > > > > Overall I believe that the interfaces and the proposal is good. I > have > > > the > > > > following question though: can you delete via the iterator > > > > (Iterable<StreamRecord<T>> elements) the elements? > > > > > > > > I tried to look over the code where the eviction happens (I did not > do > > > > these since version 0.10...looks very different now :) )...the only > > > > reference I found was the EvictingWindowOperator which at the > > > > fireOrContinue has a "skip" based on the number of elements returned > > from > > > > the evictor...and these are not put in the collection to be given to > > the > > > > user function to be applied. I think these will also need to be > changed > > > to > > > > adjust to the "any operator from anywhere in the window buffer". > > > > Also - as we are on this topic - can someone explain how these > elements > > > > that are not consider anymore for the user function are actually > > deleted > > > > from the window buffer?..i did not manage to find this.. some > reference > > > to > > > > classes/code where this happens would be useful > > > > > > > > > > > > Dr. Radu Tudoran > > > > Research Engineer - Big Data Expert > > > > IT R&D Division > > > > > > > > > > > > HUAWEI TECHNOLOGIES Duesseldorf GmbH > > > > European Research Center > > > > Riesstrasse 25, 80992 München > > > > > > > > E-mail: radu.tudo...@huawei.com > > > > Mobile: +49 15209084330 > > > > Telephone: +49 891588344173 > > > > > > > > HUAWEI TECHNOLOGIES Duesseldorf GmbH > > > > Hansaallee 205, 40549 Düsseldorf, Germany, www.huawei.com > > > > Registered Office: Düsseldorf, Register Court Düsseldorf, HRB 56063, > > > > Managing Director: Bo PENG, Wanzhou MENG, Lifang CHEN > > > > Sitz der Gesellschaft: Düsseldorf, Amtsgericht Düsseldorf, HRB 56063, > > > > Geschäftsführer: Bo PENG, Wanzhou MENG, Lifang CHEN > > > > This e-mail and its attachments contain confidential information from > > > > HUAWEI, which is intended only for the person or entity whose address > > is > > > > listed above. Any use of the information contained herein in any way > > > > (including, but not limited to, total or partial disclosure, > > > reproduction, > > > > or dissemination) by persons other than the intended recipient(s) is > > > > prohibited. If you receive this e-mail in error, please notify the > > sender > > > > by phone or email immediately and delete it! > > > > > > > > > > > > -----Original Message----- > > > > From: Vishnu Viswanath [mailto:vishnu.viswanat...@gmail.com] > > > > Sent: Friday, July 22, 2016 12:43 PM > > > > To: Dev > > > > Subject: Re: [DISCUSS][FLIP-4] Enhance Window Evictor in Flink > > > > > > > > Hi, > > > > > > > > I have created a FLIP page for this enhancement > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/FLINK/FLIP-4+%3A+Enhance+Window+Evictor > > > > > > > > Thanks, > > > > Vishnu > > > > > > > > On Thu, Jul 21, 2016 at 6:53 AM, Vishnu Viswanath < > > > > vishnu.viswanat...@gmail.com> wrote: > > > > > > > > > Thanks Aljoscha. > > > > > > > > > > On Thu, Jul 21, 2016 at 4:46 AM, Aljoscha Krettek < > > aljos...@apache.org > > > > > > > > > wrote: > > > > > > > > > >> Hi, > > > > >> this, in fact, seems to be a bug. There should be something like > > > > >> windowState.clear(); > > > > >> for (IN element: projectedContents) { > > > > >> windowState.add(element); > > > > >> } > > > > >> > > > > >> after passing the elements to the window function. > > > > >> > > > > >> This is very inefficient but the only way I see of doing it right > > now. > > > > >> > > > > >> Cheers, > > > > >> Aljoscha > > > > >> > > > > >> > > > > >> On Thu, 21 Jul 2016 at 01:32 Vishnu Viswanath < > > > > >> vishnu.viswanat...@gmail.com> > > > > >> wrote: > > > > >> > > > > >> > Hi, > > > > >> > > > > > >> > When we use RocksDB as state backend, how does the backend state > > get > > > > >> > updated after some elements are evicted from the window? > > > > >> > I don't see any update call being made to remove the element > from > > > the > > > > >> state > > > > >> > stored in RocksDB. > > > > >> > > > > > >> > It looks like the RocksDBListState is only having get() and > add() > > > > >> methods > > > > >> > since it is an AppendingState, but that causes the evicted > > elements > > > to > > > > >> come > > > > >> > back when the trigger is fired next time. (It works fine when I > > use > > > > >> > MemoryStateBackend) > > > > >> > > > > > >> > Is this expected behavior or am I missing something. > > > > >> > > > > > >> > Thanks, > > > > >> > Vishnu > > > > >> > > > > > >> > On Mon, Jul 18, 2016 at 7:15 AM, Vishnu Viswanath < > > > > >> > vishnu.viswanat...@gmail.com> wrote: > > > > >> > > > > > >> > > Hi Aljoscha, > > > > >> > > > > > > >> > > Thanks! Yes, I have the create page option now in wiki. > > > > >> > > > > > > >> > > Regards, > > > > >> > > Vishnu Viswanath, > > > > >> > > > > > > >> > > On Mon, Jul 18, 2016 at 6:34 AM, Aljoscha Krettek < > > > > >> aljos...@apache.org> > > > > >> > > wrote: > > > > >> > > > > > > >> > >> @Radu, addition of more window types and sorting should be > part > > > of > > > > >> > another > > > > >> > >> design proposal. This is interesting stuff but I think we > > should > > > > keep > > > > >> > >> issues separated because things can get complicated very > > quickly. > > > > >> > >> > > > > >> > >> On Mon, 18 Jul 2016 at 12:32 Aljoscha Krettek < > > > aljos...@apache.org > > > > > > > > > >> > >> wrote: > > > > >> > >> > > > > >> > >> > Hi, > > > > >> > >> > about TimeEvictor, yes, I think there should be specific > > > evictors > > > > >> for > > > > >> > >> > processing time and event time. Also, the current time > should > > > be > > > > >> > >> > retrievable from the EvictorContext. > > > > >> > >> > > > > > >> > >> > For the wiki you will need permissions. This was recently > > > changed > > > > >> > >> because > > > > >> > >> > there was too much spam. I gave you permission to add > pages. > > > Can > > > > >> you > > > > >> > >> please > > > > >> > >> > try and check if it works? > > > > >> > >> > > > > > >> > >> > Cheers, > > > > >> > >> > Aljoscha > > > > >> > >> > > > > > >> > >> > On Fri, 15 Jul 2016 at 13:28 Vishnu Viswanath < > > > > >> > >> > vishnu.viswanat...@gmail.com> wrote: > > > > >> > >> > > > > > >> > >> >> Hi all, > > > > >> > >> >> > > > > >> > >> >> How do we create a FLIP page, is there any permission > setup > > > > >> > required? I > > > > >> > >> >> don't see any "Create" page(after logging in) option in > the > > > > >> header as > > > > >> > >> >> mentioned in > > > > >> > >> >> > > > > >> > >> >> > > > > >> > >> > > > > >> > > > > > >> > > > > > > > > > > https://cwiki.apache.org/confluence/display/FLINK/Flink+Improvement+Proposals > > > > >> > >> >> > > > > >> > >> >> > > > > >> > >> >> Thanks, > > > > >> > >> >> Vishnu > > > > >> > >> >> > > > > >> > >> >> On Wed, Jul 13, 2016 at 10:22 PM, Vishnu Viswanath < > > > > >> > >> >> vishnu.viswanat...@gmail.com> wrote: > > > > >> > >> >> > > > > >> > >> >> > Hi Aljoscha, > > > > >> > >> >> > > > > > >> > >> >> > I agree, the user will know exactly that they are > creating > > > an > > > > >> > >> EventTime > > > > >> > >> >> > based evictor or ProcessingTime based evictor looking at > > the > > > > >> code. > > > > >> > >> >> > So do you think it will be ok to have multiple versions > of > > > > >> > >> TimeEvictor > > > > >> > >> >> > (one for event time and one for processing time) and > also > > a > > > > >> > >> DeltaEvcitor > > > > >> > >> >> > (again 2 versions- for event time and processing time) ? > > > > >> > >> >> > > > > > >> > >> >> > Please note that the existing behavior of > > > > >> TimeEvictor/DeltaEvictor > > > > >> > >> does > > > > >> > >> >> > not consider if it is EventTime or ProcessingTime > > > > >> > >> >> > e.g., in TimeEvictor the current time is considered as > the > > > > >> > timestamp > > > > >> > >> of > > > > >> > >> >> > the last element in the window > > > > >> > >> >> > > > > > >> > >> >> > *long currentTime = > > > > Iterables.getLast(elements).getTimestamp();* > > > > >> > >> >> > > > > > >> > >> >> > not the highest timestamp of all elements > > > > >> > >> >> > what I am trying to achieve is something like: > > > > >> > >> >> > > > > > >> > >> >> > *long currentTime;* > > > > >> > >> >> > * if (ctx.isEventTime()) {* > > > > >> > >> >> > * currentTime = getMaxTimestamp(elements);* > > > > >> > >> >> > * } else {* > > > > >> > >> >> > * currentTime = > > Iterables.getLast(elements).getTimestamp();* > > > > >> > >> >> > * }* > > > > >> > >> >> > > > > > >> > >> >> > Similarly, in DeltaEvictor the *`lastElement`* is > > > > >> > >> >> > *`Iterables.getLast(elements);`* and I am thinking we > > should > > > > >> > consider > > > > >> > >> >> the > > > > >> > >> >> > element with max timestamp as the last element instead > of > > > just > > > > >> > >> getting > > > > >> > >> >> the > > > > >> > >> >> > last inserted element as *`lastElement`* > > > > >> > >> >> > > > > > >> > >> >> > Do you think it is the right thing to do or leave the > > > behavior > > > > >> > >> Evictors > > > > >> > >> >> as > > > > >> > >> >> > is, w.r.t to choosing the last element? > > > > >> > >> >> > > > > > >> > >> >> > Thanks, > > > > >> > >> >> > Vishnu > > > > >> > >> >> > > > > > >> > >> >> > On Wed, Jul 13, 2016 at 11:07 AM, Aljoscha Krettek < > > > > >> > >> aljos...@apache.org > > > > >> > >> >> > > > > > >> > >> >> > wrote: > > > > >> > >> >> > > > > > >> > >> >> >> I still think it should be explicit in the class. For > > > > example, > > > > >> if > > > > >> > >> you > > > > >> > >> >> have > > > > >> > >> >> >> this code: > > > > >> > >> >> >> > > > > >> > >> >> >> input > > > > >> > >> >> >> .keyBy() > > > > >> > >> >> >> .window() > > > > >> > >> >> >> .trigger(EventTimeTrigger.create()) > > > > >> > >> >> >> .evictor(TimeTrigger.create()) > > > > >> > >> >> >> > > > > >> > >> >> >> the time behavior of the trigger is explicitly > specified > > > > while > > > > >> the > > > > >> > >> >> evictor > > > > >> > >> >> >> would dynamically adapt based on internal workings that > > the > > > > >> user > > > > >> > >> might > > > > >> > >> >> not > > > > >> > >> >> >> be aware of. Having the behavior explicit at the call > > site > > > is > > > > >> very > > > > >> > >> >> >> important, in my opinion. > > > > >> > >> >> >> > > > > >> > >> >> >> On Wed, 13 Jul 2016 at 16:28 Vishnu Viswanath < > > > > >> > >> >> >> vishnu.viswanat...@gmail.com> > > > > >> > >> >> >> wrote: > > > > >> > >> >> >> > > > > >> > >> >> >> > Hi, > > > > >> > >> >> >> > > > > > >> > >> >> >> > I was hoping to use the isEventTime method in the > > > > >> WindowAssigner > > > > >> > >> to > > > > >> > >> >> set > > > > >> > >> >> >> > that information in the EvictorContext. > > > > >> > >> >> >> > What do you think?. > > > > >> > >> >> >> > > > > > >> > >> >> >> > Thanks and Regards, > > > > >> > >> >> >> > Vishnu Viswanath, > > > > >> > >> >> >> > > > > > >> > >> >> >> > On Wed, Jul 13, 2016 at 10:09 AM, Aljoscha Krettek < > > > > >> > >> >> aljos...@apache.org > > > > >> > >> >> >> > > > > > >> > >> >> >> > wrote: > > > > >> > >> >> >> > > > > > >> > >> >> >> > > Hi, > > > > >> > >> >> >> > > I think the way to go here is to add both an > > > > >> EventTimeEvictor > > > > >> > >> and a > > > > >> > >> >> >> > > ProcessingTimeEvictor. The problem is that > > > "isEventTime" > > > > >> > cannot > > > > >> > >> >> >> really be > > > > >> > >> >> >> > > determined. That's also the reason why there is an > > > > >> > >> EventTimeTrigger > > > > >> > >> >> >> and a > > > > >> > >> >> >> > > ProcessingTimeTrigger. It was just an oversight > that > > > the > > > > >> > >> >> TimeEvictor > > > > >> > >> >> >> does > > > > >> > >> >> >> > > not also have these two versions. > > > > >> > >> >> >> > > > > > > >> > >> >> >> > > About EvictingWindowOperator, I think you can make > > the > > > > two > > > > >> > >> methods > > > > >> > >> >> >> > > non-final in WindowOperator, yes. > > > > >> > >> >> >> > > > > > > >> > >> >> >> > > Cheers, > > > > >> > >> >> >> > > Aljoscha > > > > >> > >> >> >> > > > > > > >> > >> >> >> > > On Wed, 13 Jul 2016 at 14:32 Vishnu Viswanath < > > > > >> > >> >> >> > > vishnu.viswanat...@gmail.com> > > > > >> > >> >> >> > > wrote: > > > > >> > >> >> >> > > > > > > >> > >> >> >> > > > Hi Aljoscha, > > > > >> > >> >> >> > > > > > > > >> > >> >> >> > > > I am thinking of adding a method boolean > > > isEventTime(); > > > > >> in > > > > >> > the > > > > >> > >> >> >> > > > EvictorContext apart from > > > > >> > >> >> >> > > > > > > > >> > >> >> >> > > > long getCurrentProcessingTime(); > > > > >> > >> >> >> > > > MetricGroup getMetricGroup(); > > > > >> > >> >> >> > > > long getCurrentWatermark(); > > > > >> > >> >> >> > > > > > > > >> > >> >> >> > > > This method can be used to make the Evictor not > > > iterate > > > > >> > >> through > > > > >> > >> >> all > > > > >> > >> >> >> the > > > > >> > >> >> >> > > > elements in TimeEvictor. There will be a few > > changes > > > in > > > > >> the > > > > >> > >> >> existing > > > > >> > >> >> >> > > > behavior of TimeEvictor and DeltaEvictor (I have > > > > >> mentioned > > > > >> > >> this > > > > >> > >> >> in > > > > >> > >> >> >> the > > > > >> > >> >> >> > > > design doc) > > > > >> > >> >> >> > > > > > > > >> > >> >> >> > > > Also, is there any specific reason why the open > and > > > > close > > > > >> > >> method > > > > >> > >> >> in > > > > >> > >> >> >> > > > WindowEvictor is made final? Since the > > EvictorContext > > > > >> will > > > > >> > be > > > > >> > >> in > > > > >> > >> >> the > > > > >> > >> >> >> > > > EvictingWindowOperator, I need to override the > open > > > and > > > > >> > close > > > > >> > >> in > > > > >> > >> >> >> > > > EvitingWindowOperator to make the reference of > > > > >> > EvictorContext > > > > >> > >> >> null. > > > > >> > >> >> >> > > > > > > > >> > >> >> >> > > > Thanks and Regards, > > > > >> > >> >> >> > > > Vishnu Viswanath, > > > > >> > >> >> >> > > > > > > > >> > >> >> >> > > > On Fri, Jul 8, 2016 at 7:40 PM, Vishnu Viswanath > < > > > > >> > >> >> >> > > > vishnu.viswanat...@gmail.com> wrote: > > > > >> > >> >> >> > > > > > > > >> > >> >> >> > > > My thought process when asking if we can use > state > > > > >> backend > > > > >> > in > > > > >> > >> >> window > > > > >> > >> >> >> > > > > function was : can we add the elements to be > > > evicted > > > > >> into > > > > >> > >> some > > > > >> > >> >> >> state > > > > >> > >> >> >> > > and > > > > >> > >> >> >> > > > > allow the evictAfter to read it from some > context > > > and > > > > >> > >> remove it > > > > >> > >> >> >> from > > > > >> > >> >> >> > > the > > > > >> > >> >> >> > > > > window? > > > > >> > >> >> >> > > > > > > > > >> > >> >> >> > > > > > > > > >> > >> >> >> > > > > On Fri, Jul 8, 2016 at 7:30 PM, Vishnu > Viswanath > > < > > > > >> > >> >> >> > > > > vishnu.viswanat...@gmail.com> wrote: > > > > >> > >> >> >> > > > > > > > > >> > >> >> >> > > > >> Hi Aljoscha, > > > > >> > >> >> >> > > > >> > > > > >> > >> >> >> > > > >> Thanks for the explanation, and sorry for late > > > reply > > > > >> was > > > > >> > >> busy > > > > >> > >> >> >> with > > > > >> > >> >> >> > > work. > > > > >> > >> >> >> > > > >> > > > > >> > >> >> >> > > > >> I did think about this scenario, in fact in my > > > > >> previous > > > > >> > >> mail I > > > > >> > >> >> >> > thought > > > > >> > >> >> >> > > > of > > > > >> > >> >> >> > > > >> posting this question, then I understood that > > this > > > > >> > problem > > > > >> > >> >> will > > > > >> > >> >> >> be > > > > >> > >> >> >> > > > >> there which ever method we choose(Trigger > > looking > > > > for > > > > >> > >> pattern > > > > >> > >> >> or > > > > >> > >> >> >> > > Window > > > > >> > >> >> >> > > > >> looking for pattern). > > > > >> > >> >> >> > > > >> > > > > >> > >> >> >> > > > >> I do have a pretty good watermark but my > concern > > > is > > > > >> that > > > > >> > it > > > > >> > >> >> >> changes > > > > >> > >> >> >> > > > based > > > > >> > >> >> >> > > > >> on the key of these messages(I don't know if > it > > is > > > > >> > >> possible, > > > > >> > >> >> >> haven't > > > > >> > >> >> >> > > > >> started coding that yet. May be you could tell > > > me). > > > > >> Even > > > > >> > if > > > > >> > >> >> it is > > > > >> > >> >> >> > yes > > > > >> > >> >> >> > > > some > > > > >> > >> >> >> > > > >> of these watermarks will be long(in days), > > which I > > > > >> don't > > > > >> > >> want > > > > >> > >> >> the > > > > >> > >> >> >> > > > trigger > > > > >> > >> >> >> > > > >> to wait that long. > > > > >> > >> >> >> > > > >> > > > > >> > >> >> >> > > > >> It looks like it is not easy to have an > > evictAfter > > > > >> based > > > > >> > on > > > > >> > >> >> >> window > > > > >> > >> >> >> > > > >> function(without introducing coupling), but > can > > > the > > > > >> > current > > > > >> > >> >> >> window > > > > >> > >> >> >> > > apply > > > > >> > >> >> >> > > > >> function be modified to allow it to change the > > > > >> elements > > > > >> > in > > > > >> > >> it > > > > >> > >> >> - > > > > >> > >> >> >> may > > > > >> > >> >> >> > be > > > > >> > >> >> >> > > > >> using some state backend(I don't know how > > excatly > > > > the > > > > >> > >> >> internals > > > > >> > >> >> >> of > > > > >> > >> >> >> > > these > > > > >> > >> >> >> > > > >> work, so this might be a wrong question) > > > > >> > >> >> >> > > > >> > > > > >> > >> >> >> > > > >> Thanks and Regards, > > > > >> > >> >> >> > > > >> Vishnu Viswanath, > > > > >> > >> >> >> > > > >> > > > > >> > >> >> >> > > > >> On Fri, Jul 8, 2016 at 10:20 AM, Aljoscha > > Krettek > > > < > > > > >> > >> >> >> > > aljos...@apache.org> > > > > >> > >> >> >> > > > >> wrote: > > > > >> > >> >> >> > > > >> > > > > >> > >> >> >> > > > >>> Hi Vishnu, > > > > >> > >> >> >> > > > >>> how long would these patterns be? The Trigger > > > would > > > > >> not > > > > >> > >> have > > > > >> > >> >> to > > > > >> > >> >> >> > sort > > > > >> > >> >> >> > > > the > > > > >> > >> >> >> > > > >>> elements for every new element but just > insert > > > the > > > > >> new > > > > >> > >> >> element > > > > >> > >> >> >> into > > > > >> > >> >> >> > > an > > > > >> > >> >> >> > > > >>> internal data structure. Only when it sees > that > > > the > > > > >> > >> >> watermark is > > > > >> > >> >> >> > > past a > > > > >> > >> >> >> > > > >>> certain point would it check whether the > > pattern > > > > >> matches > > > > >> > >> and > > > > >> > >> >> >> > actually > > > > >> > >> >> >> > > > >>> Trigger. > > > > >> > >> >> >> > > > >>> > > > > >> > >> >> >> > > > >>> A general note regarding order and event > time: > > I > > > > >> think > > > > >> > >> >> relying > > > > >> > >> >> >> on > > > > >> > >> >> >> > > this > > > > >> > >> >> >> > > > >>> for > > > > >> > >> >> >> > > > >>> computation is very tricky unless the > watermark > > > is > > > > >> 100 % > > > > >> > >> >> >> correct or > > > > >> > >> >> >> > > you > > > > >> > >> >> >> > > > >>> completely discard elements that arrive after > > the > > > > >> > >> watermark, > > > > >> > >> >> >> i.e. > > > > >> > >> >> >> > > > >>> elements > > > > >> > >> >> >> > > > >>> that would break the promise of the watermark > > > that > > > > no > > > > >> > >> >> elements > > > > >> > >> >> >> with > > > > >> > >> >> >> > > an > > > > >> > >> >> >> > > > >>> earlier timestamp will ever arrive. The > reason > > > for > > > > >> this > > > > >> > is > > > > >> > >> >> that > > > > >> > >> >> >> > there > > > > >> > >> >> >> > > > >>> could > > > > >> > >> >> >> > > > >>> always enter new elements that end up between > > > > already > > > > >> > seen > > > > >> > >> >> >> > elements. > > > > >> > >> >> >> > > > For > > > > >> > >> >> >> > > > >>> example, let's say we have this sequence of > > > > elements > > > > >> > when > > > > >> > >> the > > > > >> > >> >> >> > trigger > > > > >> > >> >> >> > > > >>> fires: > > > > >> > >> >> >> > > > >>> > > > > >> > >> >> >> > > > >>> a-b-a > > > > >> > >> >> >> > > > >>> > > > > >> > >> >> >> > > > >>> This is the sequence that you are looking for > > and > > > > you > > > > >> > emit > > > > >> > >> >> some > > > > >> > >> >> >> > > result > > > > >> > >> >> >> > > > >>> from > > > > >> > >> >> >> > > > >>> the WindowFunction. Now, new elements arrive > > that > > > > >> fall > > > > >> > in > > > > >> > >> >> >> between > > > > >> > >> >> >> > the > > > > >> > >> >> >> > > > >>> elements we already have: > > > > >> > >> >> >> > > > >>> > > > > >> > >> >> >> > > > >>> a-d-e-b-f-g-a > > > > >> > >> >> >> > > > >>> > > > > >> > >> >> >> > > > >>> This is an updated, sorted view of the actual > > > > >> event-time > > > > >> > >> >> stream > > > > >> > >> >> >> and > > > > >> > >> >> >> > > we > > > > >> > >> >> >> > > > >>> didn't realize that the stream actually looks > > > like > > > > >> this > > > > >> > >> >> before. > > > > >> > >> >> >> > Does > > > > >> > >> >> >> > > > this > > > > >> > >> >> >> > > > >>> still match the original pattern or should we > > now > > > > >> > consider > > > > >> > >> >> this > > > > >> > >> >> >> as > > > > >> > >> >> >> > > > >>> non-matching? If no, then the earlier > > successful > > > > >> match > > > > >> > for > > > > >> > >> >> a-b-a > > > > >> > >> >> >> > was > > > > >> > >> >> >> > > > >>> wrong > > > > >> > >> >> >> > > > >>> and we should never have processed it but we > > > didn't > > > > >> know > > > > >> > >> at > > > > >> > >> >> the > > > > >> > >> >> >> > time. > > > > >> > >> >> >> > > > If > > > > >> > >> >> >> > > > >>> yes, then pattern matching like this can be > > done > > > in > > > > >> the > > > > >> > >> >> Trigger > > > > >> > >> >> >> by > > > > >> > >> >> >> > > > having > > > > >> > >> >> >> > > > >>> something like pattern slots: You don't have > to > > > > store > > > > >> > all > > > > >> > >> >> >> elements > > > > >> > >> >> >> > in > > > > >> > >> >> >> > > > the > > > > >> > >> >> >> > > > >>> Trigger, you just need to store possible > > > candidates > > > > >> that > > > > >> > >> >> could > > > > >> > >> >> >> > match > > > > >> > >> >> >> > > > the > > > > >> > >> >> >> > > > >>> pattern and ignore the other (in-between) > > > elements. > > > > >> > >> >> >> > > > >>> > > > > >> > >> >> >> > > > >>> Cheers, > > > > >> > >> >> >> > > > >>> Aljoscha > > > > >> > >> >> >> > > > >>> > > > > >> > >> >> >> > > > >>> On Fri, 8 Jul 2016 at 14:10 Vishnu Viswanath > < > > > > >> > >> >> >> > > > >>> vishnu.viswanat...@gmail.com> > > > > >> > >> >> >> > > > >>> wrote: > > > > >> > >> >> >> > > > >>> > > > > >> > >> >> >> > > > >>> > Hi Aljoscha, > > > > >> > >> >> >> > > > >>> > > > > > >> > >> >> >> > > > >>> > That is a good idea, trying to tie it back > to > > > the > > > > >> use > > > > >> > >> case, > > > > >> > >> >> >> > > > >>> > e.g., suppose trigger is looking for a > > pattern, > > > > >> a-b-a > > > > >> > >> and > > > > >> > >> >> >> when it > > > > >> > >> >> >> > > > sees > > > > >> > >> >> >> > > > >>> such > > > > >> > >> >> >> > > > >>> > a pattern, it will trigger the window and > it > > > > knows > > > > >> > that > > > > >> > >> now > > > > >> > >> >> >> the > > > > >> > >> >> >> > > > >>> Evictor is > > > > >> > >> >> >> > > > >>> > going to evict the element b, and trigger > > > updates > > > > >> its > > > > >> > >> >> state as > > > > >> > >> >> >> > a-a > > > > >> > >> >> >> > > > >>> (even > > > > >> > >> >> >> > > > >>> > before the window & evictor completes) and > > will > > > > be > > > > >> > >> looking > > > > >> > >> >> for > > > > >> > >> >> >> > the > > > > >> > >> >> >> > > > >>> rest of > > > > >> > >> >> >> > > > >>> > the pattern i.e., b-a. But I can think of 1 > > > > problem > > > > >> > >> here, > > > > >> > >> >> >> > > > >>> > > > > > >> > >> >> >> > > > >>> > - the events can arrive out of order, > > i.e., > > > > the > > > > >> > >> trigger > > > > >> > >> >> >> might > > > > >> > >> >> >> > be > > > > >> > >> >> >> > > > >>> seeing > > > > >> > >> >> >> > > > >>> > a pattern a-a-b but actual event time is > > > a-b-a > > > > >> then > > > > >> > >> >> trigger > > > > >> > >> >> >> > will > > > > >> > >> >> >> > > > >>> have to > > > > >> > >> >> >> > > > >>> > sort the elements in the window > everytime > > it > > > > >> sees > > > > >> > an > > > > >> > >> >> >> element. > > > > >> > >> >> >> > (I > > > > >> > >> >> >> > > > was > > > > >> > >> >> >> > > > >>> > planning to do this sorting in the > window, > > > > which > > > > >> > >> will be > > > > >> > >> >> >> less > > > > >> > >> >> >> > > > often > > > > >> > >> >> >> > > > >>> - > > > > >> > >> >> >> > > > >>> > only > > > > >> > >> >> >> > > > >>> > when the trigger fires) > > > > >> > >> >> >> > > > >>> > > > > > >> > >> >> >> > > > >>> > Thanks and Regards, > > > > >> > >> >> >> > > > >>> > Vishnu Viswanath, > > > > >> > >> >> >> > > > >>> > > > > > >> > >> >> >> > > > >>> > On Fri, Jul 8, 2016 at 6:04 AM, Aljoscha > > > Krettek > > > > < > > > > >> > >> >> >> > > > aljos...@apache.org> > > > > >> > >> >> >> > > > >>> > wrote: > > > > >> > >> >> >> > > > >>> > > > > > >> > >> >> >> > > > >>> > Hi, > > > > >> > >> >> >> > > > >>> > > come to think of it, the right place to > put > > > > such > > > > >> > >> checks > > > > >> > >> >> is > > > > >> > >> >> >> > > actually > > > > >> > >> >> >> > > > >>> the > > > > >> > >> >> >> > > > >>> > > Trigger. It would have to be a custom > > trigger > > > > >> that > > > > >> > >> >> observes > > > > >> > >> >> >> > time > > > > >> > >> >> >> > > > but > > > > >> > >> >> >> > > > >>> also > > > > >> > >> >> >> > > > >>> > > keeps some internal state machine to > decide > > > > when > > > > >> it > > > > >> > >> has > > > > >> > >> >> >> > observed > > > > >> > >> >> >> > > > the > > > > >> > >> >> >> > > > >>> > right > > > > >> > >> >> >> > > > >>> > > pattern in the window. Then the window > > > function > > > > >> > would > > > > >> > >> >> just > > > > >> > >> >> >> have > > > > >> > >> >> >> > > to > > > > >> > >> >> >> > > > >>> do the > > > > >> > >> >> >> > > > >>> > > processing and you have good separation > of > > > > >> concerns. > > > > >> > >> Does > > > > >> > >> >> >> that > > > > >> > >> >> >> > > make > > > > >> > >> >> >> > > > >>> > sense? > > > > >> > >> >> >> > > > >>> > > > > > > >> > >> >> >> > > > >>> > > I'm ignoring time and sorting by time for > > now > > > > >> > because > > > > >> > >> we > > > > >> > >> >> >> > probably > > > > >> > >> >> >> > > > >>> need > > > > >> > >> >> >> > > > >>> > > another design document for that. To me > it > > > > seems > > > > >> > like > > > > >> > >> a > > > > >> > >> >> >> bigger > > > > >> > >> >> >> > > > thing. > > > > >> > >> >> >> > > > >>> > > > > > > >> > >> >> >> > > > >>> > > Cheers, > > > > >> > >> >> >> > > > >>> > > Aljoscha > > > > >> > >> >> >> > > > >>> > > > > > > >> > >> >> >> > > > >>> > > On Thu, 7 Jul 2016 at 23:56 Vishnu > > Viswanath > > > < > > > > >> > >> >> >> > > > >>> > vishnu.viswanat...@gmail.com > > > > >> > >> >> >> > > > >>> > > > > > > > >> > >> >> >> > > > >>> > > wrote: > > > > >> > >> >> >> > > > >>> > > > > > > >> > >> >> >> > > > >>> > > > Hi, > > > > >> > >> >> >> > > > >>> > > > > > > > >> > >> >> >> > > > >>> > > > Regarding the evictAfter function, that > > > > evicts > > > > >> > >> based on > > > > >> > >> >> >> some > > > > >> > >> >> >> > > > >>> decision > > > > >> > >> >> >> > > > >>> > > made > > > > >> > >> >> >> > > > >>> > > > by the window function: I think it > will > > be > > > > >> nice > > > > >> > if > > > > >> > >> we > > > > >> > >> >> can > > > > >> > >> >> >> > come > > > > >> > >> >> >> > > > up > > > > >> > >> >> >> > > > >>> with > > > > >> > >> >> >> > > > >>> > > > something that is LESS coupled, > because I > > > can > > > > >> > think > > > > >> > >> of > > > > >> > >> >> >> > several > > > > >> > >> >> >> > > > use > > > > >> > >> >> >> > > > >>> > cases > > > > >> > >> >> >> > > > >>> > > > that depend on it. > > > > >> > >> >> >> > > > >>> > > > > > > > >> > >> >> >> > > > >>> > > > Especially in the case where there are > > late > > > > >> > arriving > > > > >> > >> >> >> > messages. > > > > >> > >> >> >> > > > Only > > > > >> > >> >> >> > > > >>> > after > > > > >> > >> >> >> > > > >>> > > > the window function is applied we could > > > tell > > > > >> what > > > > >> > >> to do > > > > >> > >> >> >> with > > > > >> > >> >> >> > > the > > > > >> > >> >> >> > > > >>> > elements > > > > >> > >> >> >> > > > >>> > > > in the window. You could apply your > > > business > > > > >> logic > > > > >> > >> >> there > > > > >> > >> >> >> to > > > > >> > >> >> >> > > > >>> determine > > > > >> > >> >> >> > > > >>> > if > > > > >> > >> >> >> > > > >>> > > > the window funciton was able to do what > > it > > > is > > > > >> > >> supposed > > > > >> > >> >> to > > > > >> > >> >> >> do, > > > > >> > >> >> >> > > if > > > > >> > >> >> >> > > > >>> yes > > > > >> > >> >> >> > > > >>> > > evict > > > > >> > >> >> >> > > > >>> > > > those elements, else(since the elements > > you > > > > are > > > > >> > >> looking > > > > >> > >> >> >> for > > > > >> > >> >> >> > > > haven't > > > > >> > >> >> >> > > > >>> > > arrived > > > > >> > >> >> >> > > > >>> > > > yet) wait and try again when the > trigger > > > gets > > > > >> > fired > > > > >> > >> >> next > > > > >> > >> >> >> > time. > > > > >> > >> >> >> > > > >>> > > > > > > > >> > >> >> >> > > > >>> > > > Thanks and Regards, > > > > >> > >> >> >> > > > >>> > > > Vishnu Viswanath, > > > > >> > >> >> >> > > > >>> > > > > > > > >> > >> >> >> > > > >>> > > > > > > > >> > >> >> >> > > > >>> > > > On Thu, Jul 7, 2016 at 9:19 AM, Radu > > > Tudoran > > > > < > > > > >> > >> >> >> > > > >>> radu.tudo...@huawei.com> > > > > >> > >> >> >> > > > >>> > > > wrote: > > > > >> > >> >> >> > > > >>> > > > > > > > >> > >> >> >> > > > >>> > > > > Hi, > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > @Aljoscha - I can understand the > reason > > > why > > > > >> you > > > > >> > >> are > > > > >> > >> >> >> > hesitant > > > > >> > >> >> >> > > to > > > > >> > >> >> >> > > > >>> > > introduce > > > > >> > >> >> >> > > > >>> > > > > "slower" windows such as the ones > that > > > > would > > > > >> > >> maintain > > > > >> > >> >> >> > sorted > > > > >> > >> >> >> > > > >>> items or > > > > >> > >> >> >> > > > >>> > > > > windows with bindings between the > > > different > > > > >> > >> entities > > > > >> > >> >> >> > > (evictor, > > > > >> > >> >> >> > > > >>> > trigger, > > > > >> > >> >> >> > > > >>> > > > > window, apply function). However, I > > think > > > > >> it's > > > > >> > >> >> possible > > > > >> > >> >> >> > just > > > > >> > >> >> >> > > to > > > > >> > >> >> >> > > > >>> > create > > > > >> > >> >> >> > > > >>> > > > more > > > > >> > >> >> >> > > > >>> > > > > types of windows. The existing ones > > > > >> > (timewindows, > > > > >> > >> >> global > > > > >> > >> >> >> > > > windows > > > > >> > >> >> >> > > > >>> ...) > > > > >> > >> >> >> > > > >>> > > can > > > > >> > >> >> >> > > > >>> > > > > remain, and just add some more > flavors > > of > > > > >> > windows > > > > >> > >> >> were > > > > >> > >> >> >> more > > > > >> > >> >> >> > > > >>> features > > > > >> > >> >> >> > > > >>> > > are > > > > >> > >> >> >> > > > >>> > > > > enabled or more functionality (e.g., > > > access > > > > >> to > > > > >> > the > > > > >> > >> >> each > > > > >> > >> >> >> > > element > > > > >> > >> >> >> > > > >>> in > > > > >> > >> >> >> > > > >>> > the > > > > >> > >> >> >> > > > >>> > > > > evictor ; possibility to delete or > mark > > > for > > > > >> > >> eviction > > > > >> > >> >> >> > elements > > > > >> > >> >> >> > > > in > > > > >> > >> >> >> > > > >>> the > > > > >> > >> >> >> > > > >>> > > > > function...) > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > Regarding the specific case of sorted > > > > >> windows, I > > > > >> > >> >> think > > > > >> > >> >> >> the > > > > >> > >> >> >> > N > > > > >> > >> >> >> > > > lon > > > > >> > >> >> >> > > > >>> N > > > > >> > >> >> >> > > > >>> > > > > complexity to sort (the worst case) > is > > > very > > > > >> > >> >> unlikely. In > > > > >> > >> >> >> > fact > > > > >> > >> >> >> > > > you > > > > >> > >> >> >> > > > >>> > have > > > > >> > >> >> >> > > > >>> > > > > almost sorted items/arrays. Moreover, > > if > > > > you > > > > >> > >> consider > > > > >> > >> >> >> that > > > > >> > >> >> >> > in > > > > >> > >> >> >> > > > >>> > > iteration X > > > > >> > >> >> >> > > > >>> > > > > all elements were sorted, then in > > > iteration > > > > >> X+1 > > > > >> > >> you > > > > >> > >> >> will > > > > >> > >> >> >> > need > > > > >> > >> >> >> > > > to > > > > >> > >> >> >> > > > >>> sort > > > > >> > >> >> >> > > > >>> > > > just > > > > >> > >> >> >> > > > >>> > > > > the newly arrived elements (M). I > would > > > > >> expect > > > > >> > >> that > > > > >> > >> >> this > > > > >> > >> >> >> > > > number M > > > > >> > >> >> >> > > > >>> > might > > > > >> > >> >> >> > > > >>> > > > be > > > > >> > >> >> >> > > > >>> > > > > significant smaller then N (elements > > that > > > > >> > exists). > > > > >> > >> >> Then > > > > >> > >> >> >> > using > > > > >> > >> >> >> > > > an > > > > >> > >> >> >> > > > >>> > > > insertion > > > > >> > >> >> >> > > > >>> > > > > sort for these new elements you would > > > have > > > > >> M * > > > > >> > N > > > > >> > >> >> >> > complexity > > > > >> > >> >> >> > > > and > > > > >> > >> >> >> > > > >>> if > > > > >> > >> >> >> > > > >>> > > M<< N > > > > >> > >> >> >> > > > >>> > > > > then the complexity is O(N). > > > Alternatively > > > > >> you > > > > >> > can > > > > >> > >> >> use a > > > > >> > >> >> >> > > binary > > > > >> > >> >> >> > > > >>> > search > > > > >> > >> >> >> > > > >>> > > > for > > > > >> > >> >> >> > > > >>> > > > > insertion and then you further reduce > > the > > > > >> > >> complexity > > > > >> > >> >> to > > > > >> > >> >> >> > > > O(logN). > > > > >> > >> >> >> > > > >>> > > > > If M is proportional to N then you > can > > > > sort M > > > > >> > and > > > > >> > >> use > > > > >> > >> >> >> merge > > > > >> > >> >> >> > > > sort > > > > >> > >> >> >> > > > >>> for > > > > >> > >> >> >> > > > >>> > > > > combining. > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > Dr. Radu Tudoran > > > > >> > >> >> >> > > > >>> > > > > Research Engineer - Big Data Expert > > > > >> > >> >> >> > > > >>> > > > > IT R&D Division > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > HUAWEI TECHNOLOGIES Duesseldorf GmbH > > > > >> > >> >> >> > > > >>> > > > > European Research Center > > > > >> > >> >> >> > > > >>> > > > > Riesstrasse 25, 80992 München > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > E-mail: radu.tudo...@huawei.com > > > > >> > >> >> >> > > > >>> > > > > Mobile: +49 15209084330 > > > > >> > >> >> >> > > > >>> > > > > Telephone: +49 891588344173 > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > HUAWEI TECHNOLOGIES Duesseldorf GmbH > > > > >> > >> >> >> > > > >>> > > > > Hansaallee 205, 40549 Düsseldorf, > > > Germany, > > > > >> > >> >> >> www.huawei.com > > > > >> > >> >> >> > > > >>> > > > > Registered Office: Düsseldorf, > Register > > > > Court > > > > >> > >> >> >> Düsseldorf, > > > > >> > >> >> >> > HRB > > > > >> > >> >> >> > > > >>> 56063, > > > > >> > >> >> >> > > > >>> > > > > Managing Director: Bo PENG, Wanzhou > > MENG, > > > > >> Lifang > > > > >> > >> CHEN > > > > >> > >> >> >> > > > >>> > > > > Sitz der Gesellschaft: Düsseldorf, > > > > >> Amtsgericht > > > > >> > >> >> >> Düsseldorf, > > > > >> > >> >> >> > > HRB > > > > >> > >> >> >> > > > >>> 56063, > > > > >> > >> >> >> > > > >>> > > > > Geschäftsführer: Bo PENG, Wanzhou > MENG, > > > > >> Lifang > > > > >> > >> CHEN > > > > >> > >> >> >> > > > >>> > > > > This e-mail and its attachments > contain > > > > >> > >> confidential > > > > >> > >> >> >> > > > information > > > > >> > >> >> >> > > > >>> from > > > > >> > >> >> >> > > > >>> > > > > HUAWEI, which is intended only for > the > > > > >> person or > > > > >> > >> >> entity > > > > >> > >> >> >> > whose > > > > >> > >> >> >> > > > >>> address > > > > >> > >> >> >> > > > >>> > > is > > > > >> > >> >> >> > > > >>> > > > > listed above. Any use of the > > information > > > > >> > contained > > > > >> > >> >> >> herein > > > > >> > >> >> >> > in > > > > >> > >> >> >> > > > any > > > > >> > >> >> >> > > > >>> way > > > > >> > >> >> >> > > > >>> > > > > (including, but not limited to, total > > or > > > > >> partial > > > > >> > >> >> >> > disclosure, > > > > >> > >> >> >> > > > >>> > > > reproduction, > > > > >> > >> >> >> > > > >>> > > > > or dissemination) by persons other > than > > > the > > > > >> > >> intended > > > > >> > >> >> >> > > > >>> recipient(s) is > > > > >> > >> >> >> > > > >>> > > > > prohibited. If you receive this > e-mail > > in > > > > >> error, > > > > >> > >> >> please > > > > >> > >> >> >> > > notify > > > > >> > >> >> >> > > > >>> the > > > > >> > >> >> >> > > > >>> > > sender > > > > >> > >> >> >> > > > >>> > > > > by phone or email immediately and > > delete > > > > it! > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > -----Original Message----- > > > > >> > >> >> >> > > > >>> > > > > From: 吕文龙(吕文龙) [mailto: > > > > >> > >> wenlong....@alibaba-inc.com] > > > > >> > >> >> >> > > > >>> > > > > Sent: Thursday, July 07, 2016 11:59 > AM > > > > >> > >> >> >> > > > >>> > > > > To: dev@flink.apache.org > > > > >> > >> >> >> > > > >>> > > > > Subject: 答复: [DISCUSS] Enhance Window > > > > >> Evictor in > > > > >> > >> >> Flink > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > HI, > > > > >> > >> >> >> > > > >>> > > > > I think it is necessary to support > > sorted > > > > >> > window, > > > > >> > >> >> which > > > > >> > >> >> >> can > > > > >> > >> >> >> > > > avoid > > > > >> > >> >> >> > > > >>> > > > scanning > > > > >> > >> >> >> > > > >>> > > > > all the elements of window while > trying > > > to > > > > >> > >> evicting > > > > >> > >> >> >> > element, > > > > >> > >> >> >> > > > >>> which > > > > >> > >> >> >> > > > >>> > may > > > > >> > >> >> >> > > > >>> > > > cost > > > > >> > >> >> >> > > > >>> > > > > many IO operations, such as querying > > DBs > > > to > > > > >> get > > > > >> > >> >> elements > > > > >> > >> >> >> > from > > > > >> > >> >> >> > > > >>> state. > > > > >> > >> >> >> > > > >>> > > > > What's more, when an window > aggregation > > > > >> function > > > > >> > >> is > > > > >> > >> >> >> > > invertible, > > > > >> > >> >> >> > > > >>> such > > > > >> > >> >> >> > > > >>> > as > > > > >> > >> >> >> > > > >>> > > > > sum, which can be updated by adding > or > > > > >> removing > > > > >> > a > > > > >> > >> >> single > > > > >> > >> >> >> > > > record, > > > > >> > >> >> >> > > > >>> > window > > > > >> > >> >> >> > > > >>> > > > > results can be incrementally > > calculated. > > > In > > > > >> this > > > > >> > >> >> kind of > > > > >> > >> >> >> > > case, > > > > >> > >> >> >> > > > >>> we can > > > > >> > >> >> >> > > > >>> > > > > dramatically improve the performance > of > > > > >> window > > > > >> > >> >> >> aggregation, > > > > >> > >> >> >> > > if > > > > >> > >> >> >> > > > >>> > evictor > > > > >> > >> >> >> > > > >>> > > > can > > > > >> > >> >> >> > > > >>> > > > > trigger update of window aggregation > > > state > > > > by > > > > >> > some > > > > >> > >> >> >> > mechanism. > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > Best Wishes! > > > > >> > >> >> >> > > > >>> > > > > --- > > > > >> > >> >> >> > > > >>> > > > > wenlong.lwl > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > -----邮件原件----- > > > > >> > >> >> >> > > > >>> > > > > 发件人: Aljoscha Krettek [mailto: > > > > >> > aljos...@apache.org > > > > >> > >> ] > > > > >> > >> >> >> > > > >>> > > > > 发送时间: 2016年7月7日 17:32 > > > > >> > >> >> >> > > > >>> > > > > 收件人: dev@flink.apache.org > > > > >> > >> >> >> > > > >>> > > > > 主题: Re: [DISCUSS] Enhance Window > > Evictor > > > in > > > > >> > Flink > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > Hi, > > > > >> > >> >> >> > > > >>> > > > > regarding "sorting the window by > event > > > > >> time": I > > > > >> > >> also > > > > >> > >> >> >> > > considered > > > > >> > >> >> >> > > > >>> this > > > > >> > >> >> >> > > > >>> > > but > > > > >> > >> >> >> > > > >>> > > > > in the end I don't think it's > > necessary. > > > > >> Sorting > > > > >> > >> is > > > > >> > >> >> >> rather > > > > >> > >> >> >> > > > >>> expensive > > > > >> > >> >> >> > > > >>> > > and > > > > >> > >> >> >> > > > >>> > > > > making decisions based on the order > of > > > > >> elements > > > > >> > >> can > > > > >> > >> >> be > > > > >> > >> >> >> > > tricky. > > > > >> > >> >> >> > > > An > > > > >> > >> >> >> > > > >>> > > extreme > > > > >> > >> >> >> > > > >>> > > > > example of why this can be > problematic > > is > > > > the > > > > >> > case > > > > >> > >> >> where > > > > >> > >> >> >> > all > > > > >> > >> >> >> > > > >>> elements > > > > >> > >> >> >> > > > >>> > > in > > > > >> > >> >> >> > > > >>> > > > > the window have the same timestamp. > > Now, > > > if > > > > >> you > > > > >> > >> >> decide > > > > >> > >> >> >> to > > > > >> > >> >> >> > > evict > > > > >> > >> >> >> > > > >>> the > > > > >> > >> >> >> > > > >>> > > > first 5 > > > > >> > >> >> >> > > > >>> > > > > elements based on timestamp order you > > > > >> basically > > > > >> > >> >> >> arbitrarily > > > > >> > >> >> >> > > > >>> evict 5 > > > > >> > >> >> >> > > > >>> > > > > elements. I think the better solution > > for > > > > >> doing > > > > >> > >> >> >> time-based > > > > >> > >> >> >> > > > >>> eviction > > > > >> > >> >> >> > > > >>> > is > > > > >> > >> >> >> > > > >>> > > to > > > > >> > >> >> >> > > > >>> > > > > do one pass over the elements to get > an > > > > >> overview > > > > >> > >> of > > > > >> > >> >> the > > > > >> > >> >> >> > > > timestamp > > > > >> > >> >> >> > > > >>> > > > > distribution, then do a second pass > and > > > > evict > > > > >> > >> >> elements > > > > >> > >> >> >> > based > > > > >> > >> >> >> > > on > > > > >> > >> >> >> > > > >>> what > > > > >> > >> >> >> > > > >>> > > was > > > > >> > >> >> >> > > > >>> > > > > learned in the first pass. This has > > > > >> complexity > > > > >> > 2*n > > > > >> > >> >> >> compared > > > > >> > >> >> >> > > to > > > > >> > >> >> >> > > > >>> the > > > > >> > >> >> >> > > > >>> > > n*log > > > > >> > >> >> >> > > > >>> > > > n > > > > >> > >> >> >> > > > >>> > > > > (plus the work of actually deciding > > what > > > to > > > > >> > >> evict) of > > > > >> > >> >> >> the > > > > >> > >> >> >> > > sort > > > > >> > >> >> >> > > > >>> based > > > > >> > >> >> >> > > > >>> > > > > strategy. > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > I might be wrong, though, and there > > could > > > > be > > > > >> a > > > > >> > >> valid > > > > >> > >> >> >> > use-case > > > > >> > >> >> >> > > > not > > > > >> > >> >> >> > > > >>> > > covered > > > > >> > >> >> >> > > > >>> > > > > by the above idea. > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > regarding Vishnu's other use case of > > > > evicting > > > > >> > >> based > > > > >> > >> >> on > > > > >> > >> >> >> some > > > > >> > >> >> >> > > > >>> decision > > > > >> > >> >> >> > > > >>> > in > > > > >> > >> >> >> > > > >>> > > > the > > > > >> > >> >> >> > > > >>> > > > > WindowFunction: could this be solved > by > > > > doing > > > > >> > the > > > > >> > >> >> check > > > > >> > >> >> >> for > > > > >> > >> >> >> > > the > > > > >> > >> >> >> > > > >>> > pattern > > > > >> > >> >> >> > > > >>> > > > in > > > > >> > >> >> >> > > > >>> > > > > the evictor itself instead of in the > > > window > > > > >> > >> function? > > > > >> > >> >> >> I'm > > > > >> > >> >> >> > > very > > > > >> > >> >> >> > > > >>> > hesitant > > > > >> > >> >> >> > > > >>> > > > to > > > > >> > >> >> >> > > > >>> > > > > introduce a coupling between the > > > different > > > > >> > >> >> components of > > > > >> > >> >> >> > the > > > > >> > >> >> >> > > > >>> > windowing > > > > >> > >> >> >> > > > >>> > > > > system, i.e. assigner, trigger, > evictor > > > and > > > > >> > window > > > > >> > >> >> >> > function. > > > > >> > >> >> >> > > > The > > > > >> > >> >> >> > > > >>> > reason > > > > >> > >> >> >> > > > >>> > > > is > > > > >> > >> >> >> > > > >>> > > > > that using an evictor has a huge > > > > performance > > > > >> > >> impact > > > > >> > >> >> >> since > > > > >> > >> >> >> > the > > > > >> > >> >> >> > > > >>> system > > > > >> > >> >> >> > > > >>> > > > always > > > > >> > >> >> >> > > > >>> > > > > has to keep all elements and cannot > to > > > > >> > incremental > > > > >> > >> >> >> > > aggregation > > > > >> > >> >> >> > > > of > > > > >> > >> >> >> > > > >>> > > window > > > > >> > >> >> >> > > > >>> > > > > results and I therefore don't want to > > put > > > > >> > specific > > > > >> > >> >> >> features > > > > >> > >> >> >> > > > >>> regarding > > > > >> > >> >> >> > > > >>> > > > > eviction into the other components. > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > Cheers, > > > > >> > >> >> >> > > > >>> > > > > Aljoscha > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > On Thu, 7 Jul 2016 at 10:00 Radu > > Tudoran > > > < > > > > >> > >> >> >> > > > >>> radu.tudo...@huawei.com> > > > > >> > >> >> >> > > > >>> > > > wrote: > > > > >> > >> >> >> > > > >>> > > > > > > > > >> > >> >> >> > > > >>> > > > > > Hi, > > > > >> > >> >> >> > > > >>> > > > > > > > > > >> > >> >> >> > > > >>> > > > > > I think the situation Vishnu raised > > is > > > > >> > something > > > > >> > >> >> that > > > > >> > >> >> >> > > should > > > > >> > >> >> >> > > > be > > > > >> > >> >> >> > > > >>> > > > > accounted. > > > > >> > >> >> >> > > > >>> > > > > > It can happen indeed that you want > to > > > > >> > condition > > > > >> > >> >> what > > > > >> > >> >> >> you > > > > >> > >> >> >> > > > evict > > > > >> > >> >> >> > > > >>> from > > > > >> > >> >> >> > > > >>> > > > > > the window based on the result of > the > > > > >> function > > > > >> > >> to > > > > >> > >> >> be > > > > >> > >> >> >> > > applied. > > > > >> > >> >> >> > > > >>> > > > > > > > > > >> > >> >> >> > > > >>> > > > > > My 2 cents... > > > > >> > >> >> >> > > > >>> > > > > > I would suggest adding a list for > the > > > > >> elements > > > > >> > >> of > > > > >> > >> >> the > > > > >> > >> >> >> > > stream > > > > >> > >> >> >> > > > >>> where > > > > >> > >> >> >> > > > >>> > > you > > > > >> > >> >> >> > > > >>> > > > > > can MARK them to be delete. > > > Alternatively > > > > >> the > > > > >> > >> >> iterator > > > > >> > >> >> >> > can > > > > >> > >> >> >> > > be > > > > >> > >> >> >> > > > >>> > > extended > > > > >> > >> >> >> > > > >>> > > > > > to have a function > > > > >> > >> Iterator.markForEviction(int); > > > > >> > >> >> >> These > > > > >> > >> >> >> > can > > > > >> > >> >> >> > > > be > > > > >> > >> >> >> > > > >>> made > > > > >> > >> >> >> > > > >>> > > > > > available also in the apply > function. > > > > >> > Moreover, > > > > >> > >> we > > > > >> > >> >> can > > > > >> > >> >> >> > use > > > > >> > >> >> >> > > > >>> this to > > > > >> > >> >> >> > > > >>> > > > > > extend the functionality such that > > you > > > > add > > > > >> > MARKs > > > > >> > >> >> >> either > > > > >> > >> >> >> > for > > > > >> > >> >> >> > > > >>> > eviction > > > > >> > >> >> >> > > > >>> > > > > > after the function has finished > > > > triggering > > > > >> or > > > > >> > >> to be > > > > >> > >> >> >> > evicted > > > > >> > >> >> >> > > > in > > > > >> > >> >> >> > > > >>> the > > > > >> > >> >> >> > > > >>> > > next > > > > >> > >> >> >> > > > >>> > > > > iteration. > > > > >> > >> >> >> > > > >>> > > > > > > > > > >> > >> >> >> > > > >>> > > > > > > > > > >> > >> >> >> > > > >>> > > > > > Dr. Radu Tudoran > > > > >> > >> >> >> > > > >>> > > > > > Research Engineer - Big Data Expert > > > > >> > >> >> >> > > > >>> > > > > > IT R&D Division > > > > >> > >> >> >> > > > >>> > > > > > > > > > >> > >> >> >> > > > >>> > > > > > > > > > >> > >> >> >> > > > >>> > > > > > HUAWEI TECHNOLOGIES Duesseldorf > GmbH > > > > >> > >> >> >> > > > >>> > > > > > European Research Center > > > > >> > >> >> >> > > > >>> > > > > > Riesstrasse 25, 80992 München > > > > >> > >> >> >> > > > >>> > > > > > > > > > >> > >> >> >> > > > >>> > > > > > E-mail: radu.tudo...@huawei.com > > > > >> > >> >> >> > > > >>> > > > > > Mobile: +49 15209084330 > > > > >> > >> >> >> > > > >>> > > > > > Telephone: +49 891588344173 > > > > >> > >> >> >> > > > >>> > > > > > > > > > >> > >> >> >> > > > >>> > > > > > HUAWEI TECHNOLOGIES Duesseldorf > GmbH > > > > >> > >> >> >> > > > >>> > > > > > Hansaallee 205, 40549 Düsseldorf, > > > > Germany, > > > > >> > >> >> >> > www.huawei.com > > > > >> > >> >> >> > > > >>> > Registered > > > > >> > >> >> >> > > > >>> > > > > > Office: Düsseldorf, Register Court > > > > >> Düsseldorf, > > > > >> > >> HRB > > > > >> > >> >> >> 56063, > > > > >> > >> >> >> > > > >>> Managing > > > > >> > >> >> >> > > > >>> > > > > > Director: Bo PENG, Wanzhou MENG, > > Lifang > > > > >> CHEN > > > > >> > >> Sitz > > > > >> > >> >> der > > > > >> > >> >> >> > > > >>> Gesellschaft: > > > > >> > >> >> >> > > > >>> > > > > > Düsseldorf, Amtsgericht Düsseldorf, > > HRB > > > > >> 56063, > > > > >> > >> >> >> > > > >>> > > > > > Geschäftsführer: Bo PENG, Wanzhou > > MENG, > > > > >> Lifang > > > > >> > >> CHEN > > > > >> > >> >> >> This > > > > >> > >> >> >> > > > >>> e-mail and >
