Since the aggregate() function on a keyed window stream does not allow using rich functions, I can only use an AggregateFunction. Is the accumulator state of the AggregateFunction backed by RocksDB and persisted in checkpoints if I use the RocksDB backend. My job looks like the following,
sourceStream.keyBy(…) .timeWindow(Time.seconds(…)) .trigger(CountTrigger.of(…)) .aggregate(new MyAggFunc()); Since the stream has high cardinality keys, each window could have millions of them. If the accumulator state is not backed by RocksDB, there might be a lot of data stored on the heap. And why is rich functions not allowed here? Thanks, — Ning
