Re: [Xen-API] xapi restarts

[Ben Pfaff <blp@xxxxxxxxxxxxxxx>]

Dave Scott writes:

> I thought this article was interesting:
>
> http://blog.nella.org/?p=879
>
> It describes how nginx can perform zero downtime upgrades by:
> * fork and exec'ing the new process, deliberately passing in the listening 
> HTTP socket
> * completing the processing of old requests and shutting down the old server

This is a little tangential to your topic (which I find to be
interesting), but anyway...

I've thought about doing something similar with Open vSwitch, to
allow upgrades without disrupting connections to OpenFlow and
OVSDB clients, but I got stuck when I realized that I didn't know
of a way to pass the state associated with an SSL connection from
one process to another.  I guess the problem is simpler in the
case of HTTP, where the clients are accustomed to short-lived
connections.  OpenFlow and OVSDB both use long-lived connections
in which the clients do a fair amount of synchronization work
at connection startup time, so dropping client connections and
forcing the clients to reconnect would lose most of the benefit
of descriptor passing.


_______________________________________________
Xen-api mailing list
Xen-api@xxxxxxxxxxxxx
http://lists.xen.org/cgi-bin/mailman/listinfo/xen-api