"You can have pacemaker ping an IP (gateway for example) and migrate the VIP based on that" How does this help for splitbrain? If I understand what you say, pacemaker will ping an IP and if successfull will assume that the other node has crashed. But what if the other node hasn't and it is just their communication link that failed? Won't both become primary? How does the ping help?
________________________________ From: David Coulson <[email protected]> To: Hermes Flying <[email protected]> Cc: Baptiste <[email protected]>; "[email protected]" <[email protected]> Sent: Thursday, November 29, 2012 10:26 PM Subject: Re: HAproxy and detect split-brain (network failures) On 11/29/12 3:11 PM, Hermes Flying wrote: I see now! >One last question since you are using Pacemaker. Do you recommend it for splitbrain so that I look into that direction? > Any two node cluster has risk of split brain. if you implement fencing/STONITH, you are in a better place. If you have a third node, that's even better, even if it does not actually run any services beyond the cluster software I mean when you say that pacemaker restart HAProxy, does it detect network failures as well? Or only SW crashes? >I assume pacemaker will be aware of both HAProxy1 and HAProxy2 in my described deployment > You can have pacemaker ping an IP (gateway for example) and migrate the VIP based on that. In my config I have haproxy configured as a cloned resource in pacemaker, so all nodes have the same pacemaker config for haproxy and it keeps haproxy running on all nodes all of the time.
