Hi, >From what you described, does the key have the same type before and after the change? and for using Lambda expression, maybe the doc[1] can be helpful(especially the limitation)
[1] https://ci.apache.org/projects/flink/flink-docs-release-1.8/dev/java_lambdas.html#examples-and-limitations Best, Congxian Andrea Gallina <gallina.andre...@yahoo.it> 于2019年8月12日周一 下午7:45写道： > Hi everyone, > > I have a job running in production whose structure is approximately this; > > stream > ?? .filter(inboundData -> inboundData.hasToBeFiltered()) > ?? .keyBy("myKey") > ?? .process(doSomething()); > > I've recently decided to test the extent to which I can change a job's > structure without breaking backward compatibility; more specifically, > I've tried to change the way the key is defined in the keyBy() operator > by defining it as a lambda function rather than by field expression. The > modified structure would therefore look like this: > > stream > ?? .filter(inboundData -> inboundData.hasToBeFiltered()) > ?? .keyBy(inboundData -> inboundData.getMyKey()) > ?? .process(doSomething()); > > I then tried to run the new job by restoring the savepoint taken with > the old structure, but I get a state migration exception: > > org.apache.flink.util.StateMigrationException: The new key serializer > must be compatible > > Now this was a bit unexpected since changing the way a key is defined > does not seem like a breaking change (unlike changing the actual key > used for partitioning). > > Is this an expected behavior or am I missing something? > > Thanks > > > --- > Questa e-mail ? stata controllata per individuare virus con Avast > antivirus. > https://www.avast.com/antivirus > >
