We should not change NameNodeProxies. NN is not involved in journal synchronization.
fixed by creating a static method in JournalService to get the roc proxy.
For the same reason, the principals in JournalSyncProtocolPB should not be Namenode.
Replaced with Journal User Name
Use FSEditLog.getEditLogManifest(long fromTxId) instead of FileJournalManager and don't change FileJournalManager.
Why DN is related to JournalSyncProtocol? Please check the comments.
I think we should pass JournalInfo in getEditLogManifest(..) so that it could first verify the version, namespace id, etc.
Why the test is commented out?