I have an application configured in a cluster with a properly configured session manager. When one of the servers fails, others can handle the requests and the application is still on. All works great with the exception of an UI configured with server Push (streaming or websocket). Of course I don’t expect the connections to be still alive on the other server, but what I am try to do is the cacth the terminal exception (closed socket or whatever) and “refresh” the UI, so new requests will be handled by the new server.
You can test this behaviour without a cluster by simply restarting the tomcat with a deployed app. When the tomcat restarts, the user gets an Internal error, but when he refreshes, he gets things working, the session is the same (all the data in session is preserved). What I want to do is avoid the “Internal Error” message and “auto refresh” the UI in order to open a new connection. I think the way to do that is something with the client connector.
By searching on the Internet I found this (for Vaadin 6):
@Override public void terminalError(Terminal.ErrorEvent event) { // Call the default implementation. super.terminalError(event); // Some custom behaviour.
if (getMainWindow() != null) { getMainWindow().showNotification(
“An unchecked exception occured!”,
event.getThrowable().toString(),
Notification.TYPE_ERROR_MESSAGE);
}
}
But on Vaadin 7, you supposedly must use setErrorHandler and pass an object that implements the propper interface. However, the “Internal error” that you see in notification in scenario described above is not caught by it. The default behaviour of vaadin is to show the “Internal Error” notification and give up of reopening connection. I want to override this beheviour by either trying to reopen the connection or simply refresh the UI. How can that be accomplished?
