On Tue, Mar 3, 2009 at 11:44 PM, Martin Karbon <martin.kar...@asbz.it> wrote: > just wanted to know if anyone knows an opensource solution for a so called > transparent failover: what I mean with that is, I installed two machines > with haproxy on it which comunicate with each other via heartbeat. If one > fails the other one goes from passive to active but all sessions are lost > and users have to reconnect.
We use Heartbeat (http://www.keepalived.org/) for this. Heartbeat lets us set up virtual service IPs which are reassigned to another box if the box goes down. Works like a charm. Current connections are lost, but new ones go to the new IP. Note that there are two current versions of Heartbeat. There's the old 1.x series, which is simple and stable, but which has certain limitations such as only supporting two nodes, if I remember correctly. Then there's 2.x, which is much more complex and less stable. We run 2.0.7 today, and we have had some situations where the Heartbeat processes have run wild. It's been running quietly for over a year now, so recent patches may have fixed the issues. I would still recommend sticking with 1.x if at all possible. While there are solutions out there that preserve connections on failover, my gut feeling is that they introduce a level of complexity and computational overhead that is necessarily puts a restraint on performance. Alexander.
