Re: [DISCUSS] KIP-362: Dynamic Session Window Support

2019-11-24 Thread Matthias J. Sax
Moved this KIP into status "inactive". Feel free to resume and any time. -Matthias On 1/9/19 10:18 PM, Guozhang Wang wrote: > Hello Lei, > > Just checking what's the current status of this KIP. We have a KIP deadline > for 2.2 on 24th and wondering if this one may be able to make it. > > >

Re: [DISCUSS] KIP-362: Dynamic Session Window Support

2019-01-09 Thread Guozhang Wang
Hello Lei, Just checking what's the current status of this KIP. We have a KIP deadline for 2.2 on 24th and wondering if this one may be able to make it. Guozhang On Sat, Dec 15, 2018 at 1:01 PM Lei Chen wrote: > Sorry for the late reply Matthias. Have been busy with other work recently. >

Re: [DISCUSS] KIP-362: Dynamic Session Window Support

2018-12-15 Thread Lei Chen
Sorry for the late reply Matthias. Have been busy with other work recently. I'll restart the discussion and update the KIP accordingly. Lei On Tue, Nov 6, 2018 at 3:11 PM Matthias J. Sax wrote: > Any update on this KIP? > > On 9/20/18 3:30 PM, Matthias J. Sax wrote: > > Thanks for following

Re: [DISCUSS] KIP-362: Dynamic Session Window Support

2018-11-06 Thread Matthias J. Sax
Any update on this KIP? On 9/20/18 3:30 PM, Matthias J. Sax wrote: > Thanks for following up. Very nice examples! > > I think, that the window definition for Flink is semantically > questionable. If there is only a single record, why is the window > defined as [ts, ts+gap]? To me, this

Re: [DISCUSS] KIP-362: Dynamic Session Window Support

2018-09-20 Thread Matthias J. Sax
Thanks for following up. Very nice examples! I think, that the window definition for Flink is semantically questionable. If there is only a single record, why is the window defined as [ts, ts+gap]? To me, this definition is not sound and seems to be arbitrary. To define the windows as

Re: [DISCUSS] KIP-362: Dynamic Session Window Support

2018-09-19 Thread Lei Chen
Thanks Matthias. That makes sense. You're right that symmetric merge is necessary to ensure consistency. On the other hand, I kinda feel it defeats the purpose of dynamic gap, which is to update the gap from old value to new value. The symmetric merge always honor the larger gap in both

Re: [DISCUSS] KIP-362: Dynamic Session Window Support

2018-09-11 Thread Matthias J. Sax
Thanks for explaining your understanding. And thanks for providing more details about the use-case. Maybe you can add this to the KIP? First one general comment. I guess that my and Guozhangs understanding about gap/close/gracePeriod is the same as yours -- we might not have use the term

Re: [DISCUSS] KIP-362: Dynamic Session Window Support

2018-09-10 Thread Guozhang Wang
Hello Lei, As Matthias mentioned, the key question here is that because of the late arrivals of records which may indicate a shorter session gap interval, some session windows may be "mistakenly" merged and hence need to be undone the merge, i.e. to split them again. Back to my example, you are

Re: [DISCUSS] KIP-362: Dynamic Session Window Support

2018-09-06 Thread Matthias J. Sax
I cannot follow the example: >> (10, 10), (15, 3), (19, 5) ... First, [10,10] is created, second the window is extended to [10,15], and third [19,19] is created. Why would there be a [15,15]? And why would (19,5) be merged into [15,15] -- the gap was set to 3 via (15,3) and thus [19,19] should

Re: [DISCUSS] KIP-362: Dynamic Session Window Support

2018-08-30 Thread Lei Chen
Hi Guozhang, Thanks for reviewing the proposal. I didn't think of out of order events and glad that you brought it up. In the example you gave, (10, 10), (19, 5), (15, 3) ... my understanding is that the correct result window should be the same as in order events (10, 10), (15, 3), (19, 5)

Re: [DISCUSS] KIP-362: Dynamic Session Window Support

2018-08-24 Thread Guozhang Wang
Hello Lei, Thanks for the proposal. I've just made a quick pass over it and there is a question I have: The session windows are defined per key, i.e. does that mean that each incoming record of the key can dynamically change the gap of the window? For example, say you have the following record

[DISCUSS] KIP-362: Dynamic Session Window Support

2018-08-22 Thread Lei Chen
Hi All, I created a KIP to add dynamic gap session window support to Kafka Streams DSL. https://cwiki.apache.org/confluence/display/KAFKA/KIP-362%3A+Support+dynamic+gap+session+window Please take a look, Thanks, Lei