This issue is a tracking item for the conversation in the mailing list  which highlights multiple problems and shortcomings in the existing Java client and proposes a design change in the client connection pooling to address the same. More specifically, the problems addressed are as follows:
- Difficulty in configuring the client for optimum performance.
- Undocumented dependency of configuration parameters on each other.
- A bad request can impact other requests on the same channel.
- Host is marked as dead even if it is busy serving requests.
- No way to free up server resources if the client has stopped consuming results.
- No differentiation between retriable and non-retriable exceptions from the application code.
- Keep alive is only sent when a query is executing, which means that a connection open for a very long time with no query being sent will be closed by the server.
- Race condition if the server response reaches before result queue has been registered.
- Unpredictable behaviour if the server sends an exception followed by a genuine response for the same request.
- A concurrent hash map (tracking pending requests) is a point of contention amongst threads.