Hi Michael, We would need more information to be able to help. We don't serialize scala objects and clients should be able to use different Scala versions than the broker. Do you have a stacktrace of when the exception is thrown?
Ismael On Fri, Apr 15, 2016 at 2:39 PM, Michael D. Coon <mdco...@yahoo.com.invalid> wrote: > We are seeing odd behavior that we need to understand. We are getting > IncompatibleClassChangeErrors and I know that's related to a Scala version > mismatch. What's not clear, however, is where or why the mismatch is > occurring. We know up front that there were occasions where we ran apps > that had Scala 2.10 dependencies with the 0.9 consumer. We also plugged in > a metrics reporter at the broker with 2.10 scala dependencies. Both of > these situations produced the class change errors and they both appear to > be around the consumer offsets topic. Is there something under the hood > that is serializing a scala object that would cause this issue? The only > fix appears to be blowing away all data in the __consumer_offsets topic and > starting over with 2.11 clients. Is this expected behavior? Seems like a > weakness if so because we have no control, in some cases, what version of > Scala a client might use. > >
