Best practices using the Gremlin Java client with Neptune
Use the latest compatible version of the Apache TinkerPop Java client
If you can, always use the latest version of the Apache TinkerPop Gremlin Java client supported by the engine version you are using. Newer versions contain numerous bug fixes which can improves the stability, performance and usability of the client.
See Apache TinkerPop Java Gremlin client for a list of the client versions that are compatible with various Neptune engine versions.