Hello, A bit of an ugly hack, but maybe you could manually create a class named exactly io.relayr.counter.FttCounter$$anon$71$$anon$33, and copy-paste into it the code that the macro is expanded into ?
Best, Gábor  https://stackoverflow.com/questions/11677609/how-do-i-print-an-expanded-macro-in-scala On Tue, Apr 10, 2018 at 6:06 PM, Petter Arvidsson <petter.arvids...@relayr.io> wrote: > Hello everyone, > > We are trying to recover state from a snapshot which we can no longer load. > When it is loaded we receive the following exception: > java.lang.ClassNotFoundException: > io.relayr.counter.FttCounter$$anon$71$$anon$33 > This, via a couple more exceptions, leads to: > java.io.IOException: Unloadable class for type serializer. > > The cause of this behavior is an implicit macro that is part of the scala > API package, > https://github.com/apache/flink/blob/release-1.4/flink-scala/src/main/scala/org/apache/flink/api/scala/package.scala#L46. > This macro generates an anonymous class implementing TypeInformation for > classes that lack it. In our case it seems to have generated > "io.relayr.counter.FttCounter$$anon$71$$anon$33" which does not have a > stable name. When we change the class implementing the job, the name of this > anonymous class changes and we can no longer load the snapshot. > > To solve the problem we introduced an explicit TypeInformation instance > instead, which makes new instances of the job work properly. The problem is > that this new version is no longer compatible with the old state (loading it > generates the same exception), since the original TypeInformation is no > longer generated. This is due to the explicitly provided instance preventing > the macro from being executed. > > Did anyone else experience this or a similar problem? Is there a good way to > get out of this situation, i.e. how could we migrate the snapshot to one > where the state points to a TypeInformation instance with a stable class > name and not the macro generated one without losing the state? > > We are using Flink 1.4.2. > > Regards, > Petter