Re: How to reprocess historical data with event-time windowing?

2022-04-13 Thread David Anderson
stream > processor handle the rest. But if I’m understanding Flink’s windowing and > watermarks correctly for an event-time based app, there doesn’t really seem > to be a way of revisiting older data. If you’re using event-time windowing, > then any window for which (end window range + windo

How to reprocess historical data with event-time windowing?

2022-04-12 Thread Ty Brooks
older events into Kafka and let the stream processor handle the rest. But if I’m understanding Flink’s windowing and watermarks correctly for an event-time based app, there doesn’t really seem to be a way of revisiting older data. If you’re using event-time windowing, then any window for which (end

Re: Watermarks in Event Time windowing

2018-09-14 Thread David Anderson
To clarify one thing: keep in mind that Flink does not support per-key watermarks. Watermarks are typically generated per-source, or in the case of kafka, can be per-partition. An idle source (or in the case of kafka, an idle partition) can prevent an event-time window from being triggered, but you

Re: Watermarks in Event Time windowing

2018-09-13 Thread Taher Koitawala
Yes in many cases what we have faced that let's say in a keyed stream an element of a specific key comes in which triggers a new window. If a corresponding elements of the same key does not arrive a new watermark is not generated for the window to purge. Then we faced issues with flink keeping reco

Re: Watermarks in Event Time windowing

2018-09-13 Thread vino yang
Hi Taher, For some questions, I suggest you read the documentation related to Flink EventTime first, for example [1] About this question: What happens if the watermark is same as the timestamp? Here "timestamp", do you mean the current timestamp of Processing time? If that's the best, it's an id

Watermarks in Event Time windowing

2018-09-13 Thread Taher Koitawala
Hi All, Can someone show a good example of how watermarks need to be generated when using EventTime windows? What happens if the watermark is same as the timestamp? How does the watermark help in the window to be triggered and what if watermarks are kept behind the currentTimestamps in

Re: Flink 1.1 event-time windowing changes from 1.0.3

2016-08-08 Thread Adam Warski
Thanks! I’ll be watching that issue then Adam > On 08 Aug 2016, at 05:01, Aljoscha Krettek wrote: > > Hi Adam, > sorry for the inconvenience. This is caused by a new file read operator, > specifically how it treats watermarks/timestamps. I opened an issue here that > describes the situation:

Re: Flink 1.1 event-time windowing changes from 1.0.3

2016-08-08 Thread Aljoscha Krettek
Hi Adam, sorry for the inconvenience. This is caused by a new file read operator, specifically how it treats watermarks/timestamps. I opened an issue here that describes the situation: https://issues.apache.org/jira/browse/FLINK-4329. I think this should be fixed for an upcoming 1.1.1 bug fixing r

Flink 1.1 event-time windowing changes from 1.0.3

2016-08-06 Thread Adam Warski
Hello, I have a very simple stream where I window data using event-time. As a data source I’m using a CSV file, sorted by increasing timestamps. Here’s the source: val env = StreamExecutionEnvironment.getExecutionEnvironment env.setStreamTimeCharacteristic(TimeCharacteristic.EventTime) val line

Re: Event-Time Windowing

2015-10-07 Thread Aljoscha Krettek
(...) >> .timeWindow(Time.of(5,TimeUnit.SECONDS)) >> // or .window(SlidingTimeWindows.of(Time.of(5, TimeUnit.SECONDS))) >> .sum(0) >> .print() >> >> I hope this helps. :D >> >> Cheers, >> Aljoscha >> >> >> On Wed, 7 Oct 2

Re: Event-Time Windowing

2015-10-07 Thread Aljoscha Krettek
(...) >> .timeWindow(Time.of(5,TimeUnit.SECONDS)) >> // or .window(SlidingTimeWindows.of(Time.of(5, TimeUnit.SECONDS))) >> .sum(0) >> .print() >> >> I hope this helps. :D >> >> Cheers, >> Aljoscha >> >> >> On Wed, 7 Oc

Re: Event-Time Windowing

2015-10-07 Thread Alexander Kolb
this helps. :D > > Cheers, > Aljoscha > > > On Wed, 7 Oct 2015 at 16:54 Alexander Kolb < > alexander.k...@mni.fh-giessen.de> wrote: > >> Hi Guys, >> >> I'm trying to use the event-time windowing feature. But the windowing >> does not

Re: Event-Time Windowing

2015-10-07 Thread Aljoscha Krettek
,TimeUnit.SECONDS)) // or .window(SlidingTimeWindows.of(Time.of(5, TimeUnit.SECONDS))) .sum(0) .print() I hope this helps. :D Cheers, Aljoscha On Wed, 7 Oct 2015 at 16:54 Alexander Kolb wrote: > Hi Guys, > > I'm trying to use the event-time windowing feature. But the window

Event-Time Windowing

2015-10-07 Thread Alexander Kolb
Hi Guys, I'm trying to use the event-time windowing feature. But the windowing does not work as expected. What I've been doing is to write my own source which implements the EventTimeSourceFunction and uses the collectWithTimeStamp method. Additionally I'm emitting a water