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Tag: apache-flink

How to see restored value from savepoints?

I have tried to log info about states that recovered when I start a Flink app using savepoints. I see that the app was started using a savepoint correctly. But I can’t log state values that were recovered. The app calculates how many products were bought. Can I use CheckpointedFunction in such way? I see that context.isRestored() return true, but

Developing job for Flink

I am building a simple data pipeline for learning purposes. I have real time data coming from Kafka, I would like to do some transformations using Flink. Unfortunately, I’m not sure if I understand correctly deployment options. In the the Flink docs I have found section about Docker Compose and application mode. It says that I can deploy only one

javadoc of SingleOutputStreamOperator#returns(TypeHint typeHint) method

I am reading the source code of SingleOutputStreamOperator#returns, its javadoc is: It mentions FunctionWithNonInferrableReturnType to show case the necessity of returns method, but I am unable to write such a class that is NonInferrableReturnType. Could you please help write a simple one? Thanks! Answer When the docs says NonInferrableReturnType it means that we can use the type variable <T>, or