Hi Reem, What's the Flink version where you're encountering this issue?
Best regards, Martijn On Wed, Mar 29, 2023 at 5:18 PM Reem Razak via user <user@flink.apache.org> wrote: > Hey there! > > We are seeing a second Flink pipeline encountering similar issues when > configuring both `withWatermarkAlignment` and `withIdleness`. The > unexpected behaviour gets triggered after a Kafka cluster failover. Any > thoughts on there being an incompatibility between the two? > > Thanks! > > On Wed, Nov 9, 2022 at 6:42 PM Reem Razak <reem.ra...@shopify.com> wrote: > >> Hi there, >> >> We are integrating the watermark alignment feature into a pipeline with a >> Kafka source during a "backfill"- i.e. playing from an earlier Kafka >> offset. While testing, we noticed some unexpected behaviour in the >> watermark advancement which was resolved by removing `withIdleness` from >> our watermark strategy. >> >> >> val watermarkStrategy = WatermarkStrategy >> .forBoundedOutOfOrderness(Duration.ofMinutes(1)) >> .withTimestampAssigner(new TimestampedEventTimestampAssigner[Event]) >> .withWatermarkAlignment("alignment-group-1", Duration.ofMinutes(1)) >> .withIdleness(Duration.ofMinutes(5)) >> >> I have attached a couple of screenshots of the watermarkAlignmentDrift >> metric. As you can see, the behaviour seems normal until a sudden drop in >> the value to ~ Long.MIN_VALUE, which causes the pipeline to stop emitting >> records completely from the source. Furthermore, the logs originating from >> from >> https://github.com/dawidwys/flink/blob/888162083fbb5f62f809e5270ad968db58cc9c5b/flink-runtime/src/main/java/org/apache/flink/runtime/source/coordinator/SourceCoordinator.java#L174 >> also indicate that the `maxAllowedWatermark` switches to ~ Long.MIN_VALUE. >> >> We found that modifying the `updateInterval` passed into the alignment >> parameters seemed to correlate with how long the pipeline would operate >> before stopping - a larger interval of 20 minutes would encounter the issue >> later than an interval of 1 second. >> >> We are wondering if a bug exists when using both `withIdleness` and >> `withWatermarkAlignment`. Might it be related to >> https://issues.apache.org/jira/browse/FLINK-28975, or is there possibly >> a race condition in the watermark emission? We do not necessarily need to >> have both configured at the same time, but we were also surprised by the >> behaviour of the application. Has anyone run into a similar issue or have >> further insight? >> >> Much Appreciated, >> - Reem >> >> >> >>