Enhancing Logging for Ephemeral Type Handling in EphemeralType.get() Method

The EphemeralType.get(long ephemeralOwner) method in the ZooKeeper codebase is responsible for determining the type of ephemeral node based on the provided ephemeralOwner value. The current implementation lacks sufficient logging to diagnose and understand how ephemeral types are determined, especially when dealing with extended ephemeral types. By enhancing the method with detailed logging, we can make it easier to track the logic flow and pinpoint issues when handling different ephemeralOwner values, particularly under scenarios involving extended ephemeral types and emulation of older versions.
 
Expected Behavior:
The method should log the steps it takes to determine the EphemeralType based on the provided ephemeralOwner value. This includes logging whether extended ephemeral types are enabled, if specific properties like TTL emulation are set, and the final EphemeralType that is returned. For invalid ephemeralOwner values, an error should be logged before an exception is thrown.
 
How-to-Fix:
We propose to enhance the EphemeralType.get(long ephemeralOwner) method with logging statements that detail the decision-making process for returning an EphemeralType. These logs will include the status of feature flags, the type of ephemeralOwner, and error conditions.