Additional Questions:
someone suggested adjusting the sliding acknowledgement window, which in Java by call setReceiveADWindowSize(). what is the equivalently control in Node.js library?
The most similar control is WindowSize ( PubSub+ JavaScript API Documentation ), but looks not affected.
The window size for Guaranteed Message delivery. This is the maximum number of messages that will be prefetched from the Solace Messaging Router and queued internally by the API while waiting for the application to accept delivery of the messages. The valid range is 1 <= windowSize <= 255.