I would suggest trying FlinkRunner as it is a much more complete streaming implementation. SparkRunner has several key things that are missing that won't allow your pipeline to function correctly. If you're really invested in getting SparkRunner working though feel free to contribute the necessary implementations for watermark holds and broadcast state necessary for side inputs.
On Tue, Sep 29, 2020 at 9:06 AM Rajagopal, Viswanathan <rajagop...@dnb.com> wrote: > Hi Team, > > > > I have a streaming pipeline (built using Apache Beam with Spark > Runner)which consumes events tagged with timestamps from Unbounded source > (Kinesis Stream) and batch them into FixedWindows of 5 mins each and then, > write all events in a window into a single / multiple files based on shards. > > We are trying to achieve the following through Apache Beam constructs > > *1. **Create a PCollectionView from unbounded source and pass it as > a side-input to our main pipeline.* > > *2. **Have a hook method that invokes per window that enables us to > do some operational activities per window.* > > *3. **Stop the stream processor (graceful stop) from external > system.* > > > > *Approaches that we tried for 1).* > > · Creating a PCollectionView from unbounded source and pass it as > a side-input to our main pipeline. > > · Input Pcollection goes through FixedWindow transform. > > · Created custom CombineFn that takes combines all inputs for a > window and produce single value Pcollection. > > · Output of Window transform it goes to CombineFn (custom fn) and > creates a PCollectionView from CombineFn (using > Combine.Globally().asSingletonView() as this output would be passed as a > side-input for our main pipeline. > > o Getting the following exception (while running with streaming option > set to true) > > · java.lang.IllegalStateException: No TransformEvaluator > registered for UNBOUNDED transform View.CreatePCollectionView > > - Noticed that SparkRunner doesn’t support the streaming side-inputs > in the Spark runner > - > > https://www.javatips.net/api/beam-master/runners/spark/src/main/java/org/apache/beam/runners/spark/translation/streaming/StreamingTransformTranslator.java > (View.CreatePCollectionView.class not added to EVALUATORS Map) > - https://issues.apache.org/jira/browse/BEAM-2112 > - https://issues.apache.org/jira/browse/BEAM-1564 > > So would like to understand on this BEAM-1564 ticket. > > > > *Approaches that we tried for 2).* > > Tried to implement the operational activities in extractOutput() of > CombineFn as extractOutput() called once per window. We hadn’t tested this > as this is blocked by Issue 1). > > Is there any other recommended approaches to implement this feature? > > > > *Looking for recommended approaches to implement feature 3).* > > > > Many Thanks, > > Viswa. > > > > > > > > >
