DVCS Connector initializes Data Center with wrong class loader and breaks cache replication

Summary

In a JIRA Data Center Environment, ClassNotFoundException can be seen in the logs due to the DVCS Connector initializing JIRA Data Center cache with its own classloader. This causes exceptions during removal operations from com.atlassian.jira.plugins.dvcs.service.remote.CachingCommunicator.usersCache and can break replication across nodes.

Environment

• JIRA Data Center

Steps to Reproduce

1. Setup JIRA Data Center with at least 2 nodes.
2. Observe the logs

Expected Results

Cache replicates.

Actual Results

• The below exception is thrown in the atlassian-jira.log file of healthy node:

  ehcache-replicator-19 ERROR      [c.a.j.c.cache.ehcache.BlockingParallelCacheReplicator] Exception on replication of remove. RemoteException occurred in server thread; nested exception is: 
      	java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
      	java.lang.ClassNotFoundException: com.atlassian.jira.plugins.dvcs.service.remote.CachingCommunicator$UserKey (no security manager: RMI class loader disabled). Cache: com.atlassian.jira.plugins.dvcs.service.remote.CachingCommunicator.usersCache Peer: com.atlassian.jira.plugins.dvcs.service.remote.CachingCommunicator.usersCache
  java.rmi.ServerException: RemoteException occurred in server thread; nested exception is: 
  	java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is: 
  	java.lang.ClassNotFoundException: com.atlassian.jira.plugins.dvcs.service.remote.CachingCommunicator$UserKey (no security manager: RMI class loader disabled)