Thanks,Fabian. I got around the issue by moving the logic for the DropwizardHistogramWrapper -a non serializable class into the ProcessWindowFunction's open() function.
On Fri, Jun 7, 2019 at 12:33 AM Fabian Hueske <fhue...@gmail.com> wrote: > Hi, > > There are two ways: > > 1. make the non-serializable member variable transient (meaning that it > won't be serialized) and check in the aggregate call if it has been > initialized or not. > 2. implement your own serialization logic by overriding readObject() and > writeObject() [1]. > > Best, Fabian > > [1] > https://howtodoinjava.com/java/serialization/custom-serialization-readobject-writeobject/ > > Am Do., 6. Juni 2019 um 23:04 Uhr schrieb Vijay Balakrishnan < > bvija...@gmail.com>: > >> HI, >> I have a class defined : >> >> public class MGroupingWindowAggregate implements AggregateFunction.. { >>> private final Map<String, Object> keyHistMap = new TreeMap<>(); >>> } >>> >> In the constructor, I initialize it. >> >>> public MGroupingWindowAggregate() { >>> Histogram minHist = new Histogram(new >>> SlidingTimeWindowReservoir(timeIntervalL, TimeUnit.MINUTES)); >>> org.apache.flink.metrics.Histogram minHistogram = new >>> DropwizardHistogramWrapper(minHist); >>> Map<String, org.apache.flink.metrics.Histogram> intervalHistMap = new >>> TreeMap<>(); >>> intervalHistMap.putIfAbsent(interval, minHistogram); >>> keyHistMap.putIfAbsent(operationKey, intervalHistMap); >>> } >>> >> When trying to use it in the add() method of AggregateFunction, it fails >> saying: >> NotSerializableException: >> org.apache.flink.dropwizard.metrics.DropwizardHistogramWrapper >> >> Tried to wrap DropwizardHistogramWrapper inside a serializable Object >> with Composition but that also didn't work. >> >> Looked at using RichFunction open() based on Stephan's advise here. >> https://stackoverflow.com/questions/34118469/flink-using-dagger-injections-not-serializable >> But cannot use RichFunction with AggrgeateFunction or use >> RichAggregateFunction >> >> How can I use the DropwizardHistogramWrapper -a non serializable class >> inside my AggregateFunction ? Trying to use DropwizardHistogramWrapper to >> get some Histogram percentile stats without re-inventing the wheel. >> >> TIA, >> Vijay >> >
