Disconnected browser causes Errai to repeatively throws QueueUnavailableException

[jayd.lowrider]

Hello,

So I have a code that issues a subscription from the GWT client, and the server creates a conversation with the client with replyRepeating every 2 seconds, thus creating a HTTP Streaming.

I'm guessing because the browser had been disconnected, either by closing the browser or network failure, the server should kill the worker threads for that specific client?

I don't know if GrizzlyCometServlet or DefaultBlockingQueue has way to do that.

org.jboss.errai.bus.server.QueueUnavailableException: no queue available to send. (queue or session may have expired)

at org.jboss.errai.bus.server.ServerMessageBusImpl.getQueueByMessage(ServerMessageBusImpl.java:882)

  at org.jboss.errai.bus.server.ServerMessageBusImpl.send(ServerMessageBusImpl.java:412)

at org.jboss.errai.bus.server.Worker.deliverToBus(Worker.java:143)

at org.jboss.errai.bus.server.Worker.run(Worker.java:111)

Melvin

[jayd.lowrider]

I've done a work around with conversation message on the server where replyrepeating is within 2 seconds. Since the MessageQueue is null on browser close, I've killed the repeating Async task by setting cancel(true), thereby stopping the resend.

Should the ServerMessageBus handle this? How does the server know if the request from the browser had been cut off? There should be a way for Java NIO, to tell the server the browser had been cut other than let the session die.

Kindly advice.

Melvin

[jayd.lowrider]

This workaround only works with single browser connection. I get QueueUnavailableException from multiple browser, I'll raise a bug, looking at the code, there is no way for it to remove the message queue from the Workers.

[cbrock]

Yes, we don't have a way to notify the server a client has disconnected other than experiencing a failure. This is a limit of COMET and long polling. Our WebSockets support will have the ability to detect a disconnect in real-time. But what you're describing is really tricky to do, which is why we use a heart beat model to detect if the client has died.

[patrykxes]

Hello Mike

I'm newbie.

Can you give example about heartbeat model in errai ?