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.
