Close the client to avoid the connections limit

It is important to close the client when you are finished with it to ensure that the WebSocket connections are closed by the server and all resources associated with the connections are released. This happens automatically if you close the cluster using Cluster.close( ), because client.close( ) is then called internally.

If the client is not closed properly, Neptune terminates all idle WebSocket connections after 20 to 25 minutes. However, if you don't explicitly close WebSocket connections when you're done with them and the number of live connections reaches the WebSocket concurrent connection limit, additional connections are then refused with an HTTP 429 error code. At that point, you must restart the Neptune instance to close the connections.

The advice to call cluster.close() does not apply to Java AWS Lambda functions. See Managing Gremlin WebSocket connections in AWS Lambda functions for details.