jsr356-experts@websocket-spec.java.net

[jsr356-experts] Web Socket Sessions in Distributed Servers

From: Danny Coward <danny.coward_at_oracle.com>
Date: Wed, 24 Oct 2012 18:16:18 -0700

Hello websocket experts,

One issue that came up with the Java EE group here at Oracle was how to
handle web sockets in the distributed container. This is JIRA issue 15.

Most of you will know that the web container in Java EE can be
distributed across a number of VMs. While the semantics are not crystal
clear, there is the possibility in the spec that a distributed web
container can 'move' an HttpSession from one node to another in the
event of a node failure. Since we have been thinking of the WebSocket
Session object as being a 'part' of the HttpSession corresponding to the
same client, it is not clear what should happen to a Web Socket session
this case. It seems unlikely/impossible to replicate the connection
elsewhere if a node in the cluster fails, but I don't know.

Does anyone have experience with websockets in this distributed setting
that they could talk about ? We'll need to define what is possible in
order that applications behave portably.

Thanks,

- Danny
-- 
<http://www.oracle.com> 	*Danny Coward *
Java EE
Oracle Corporation