Marshaller for JDG 7.1.0 onwards is not compatible to former versions

Issue

• Is it possible to migrate legacy versions of RHDG to 7.1.0 and onwards without rolling upgrade?

• If a JDG cluster is upgraded to version 7.1 or later the start will throw NullPointerException for some caches.

The exception root cause will be like:

Caused by: java.lang.NullPointerException: null
    at org.infinispan.marshall.core.GlobalMarshaller.readWithExternalizer(GlobalMarshaller.java:693)
    at org.infinispan.marshall.core.GlobalMarshaller.readNonNullableObject(GlobalMarshaller.java:678)
    at org.infinispan.marshall.core.GlobalMarshaller.readNullableObject(GlobalMarshaller.java:361)
    at org.infinispan.marshall.core.GlobalMarshaller.objectFromObjectInput(GlobalMarshaller.java:199)
    at org.infinispan.marshall.core.GlobalMarshaller.objectFromByteBuffer(GlobalMarshaller.java:228)
    at org.infinispan.persistence.file.SingleFileStore.rebuildIndex(SingleFileStore.java:212)
    at org.infinispan.persistence.file.SingleFileStore.start(SingleFileStore.java:126)