We have two ways to access the private zkServer inside ServerCnxnFactory, and there is really no need to keep maintaining both. We could remove ServerCnxnFactoryAccessor when we added the public accessor for ServerCnxnFactory in
ZOOKEEPER-1346, but we did not.
The solution is to consolidate all access of the zkServer through the public accessor of ServerCnxnFactory. The end result is cleaner code base and less confusion.