Thanks for your reply, Xingcan. On Wed, Nov 8, 2017 at 10:42 PM, Xingcan Cui <xingc...@gmail.com> wrote:
> Hi Shailesh, > > actually, the watermarks are generated per partition, but all of them will > be forcibly aligned to the minimum one during processing. That is decided > by the semantics of watermark and KeyedStream, i.e., the watermarks belong > to a whole stream and a stream is made up of different partitions (one per > key). > > If the physical devices work in different time systems due to delay, the > event streams from them should be treated separately. > > Hope that helps. > > Best, > Xingcan > > On Wed, Nov 8, 2017 at 11:48 PM, Shailesh Jain < > shailesh.j...@stellapps.com> wrote: > >> Hi, >> >> I'm working on implementing a use case wherein different physical devices >> are sending events, and due to network/power issues, there can be a delay >> in receiving events at Flink source. One of the operators within the flink >> job is the Pattern operator, and there are certain patterns which are time >> sensitive, so I'm using Event time characteristic. But the problem comes >> when there are unpredictable delays in events from a particular device(s), >> which causes those events to be dropped (as I cannot really define a static >> bound to allow for lateness). >> >> Since I'm using a KeyedStream, keyed on the source device ID, is there a >> way to allow each CEP operator instance (one per key) to progress its time >> based on the event time in the corresponding stream partition. Or in other >> words, is there a way to generate watermarks per partition in a KeyedStream? >> >> Thanks, >> Shailesh >> > >
