How to use metrics system or similar things for WindowedStream data?

Question

I would like to measure the throughput of each window in Apache Flink. The metrics does not fit WindowedStream since it said it does not support RichFunction as AggregateFunction. I used singleton instance instead but someone said it not good for distributed environment. (locally run ok) Are there any solutions for this situation?

Answer 1

There are built-in metrics measuring

numBytesInLocalPerSecond
numBytesInRemotePerSecond
numBytesOutPerSecond
numRecordsInPerSecond
numRecordsOutPerSecond

These throughput metrics are available out-of-the-box for every operator (except for the input metrics for sources, and output metrics for sinks), including windows.