How to wait for websockets to close gracefully on application shutdown? - quarkus

Question

We have the following issue:
Preconditions:
Quarkus application received WebSockets connections
Quarkus application is running in a pod (Kubernetes)
The WebSockets connection is going through layers of 2 load balancers (elb, nginx) but we made sure that we increased the idle connection timeout (300s)
Websocket server must wait for connection closes before the shutdown
The client for the server doesn't have a reconnect mechanism
we have a shutdown hook to wait for the WebSockets sessions closes
Scenario when the pod is about to close:
the application received a SIGTERM
Sometimes some connections (but not all) closes with Reason GOING_AWAY (indicates that an endpoint is "going away", such as a server going down or a browser having navigated away from a page)
The shutdown hook:
void onStop(#Observes final ShutdownEvent ev) {
long numActiveSessions = getActiveSessions();
while (numActiveSessions > 0) {
try {
TimeUnit.SECONDS.sleep(waitforfinished);
} catch (InterruptedException e) {
return;
}
numActiveSessions = getActiveSessions();
}
}
There is a better way to do this? Why we received the GOING_AWAY reason? Are quarkus closing the WebSockets when it received a SIGTERM?
Update:
example project: https://github.com/pedrolopix/quarkus-websockets-example