On Thu, Jun 28, 2012 at 06:50:26AM -0400, David Coulson wrote: > You're better off running haproxy via pacemaker, so if haproxy dies then > you can not have your VIP run on that host.
That's already what keepalived does, and it goes a bit further in that you can monitor the service for real, not just the process presence, and even decide several failover scenarios using floating VRRP priorities. For instance, I usually assign a weight of 4 to my haproxy process and 2 to sshd. That way, if haproxy dies, the other one takes the VIP. However, if both haproxy work and one sshd dies, the one taking the VIP is the one still reachable for administration. If one of each dies, the one with the running haproxy wins. Some more complex setups involve switching a VIP depending on the number of application servers that haproxy sees, using "monitor-fail if ...". This is handy for multi-layer architectures with an inter-DC LAN for instance. Regards, Willy
