Daemon threads for WebSocket keepalives

A WebSocket connection that needs periodic pings to stay open shouldn’t run that ping loop on a plain, non-daemon thread. In the WazirX Java connector , the ping thread is started onOpen and marked setDaemon(true) before starting it:

pingThread = new Thread(new PingMessage(this));
pingThread.setDaemon(true);
pingThread.start();

A non-daemon thread keeps the JVM alive until it finishes. If a caller opens a socket, forgets to close it, and the rest of the application shuts down, a non-daemon ping thread will keep the process running indefinitely. A daemon thread just gets killed when everything else is done — which is the right default for background keepalive work that isn’t itself the point of the program.