On 10/23/09 7:42 AM, David Carter wrote: > On Fri, 23 Oct 2009, Bron Gondwana wrote: > >> I've seen heartbeat get split brain before. We gave up on it. We do >> all our fencing via humans now! Check the KVM, kick the box, manually >> run the failover script. > > Some of my colleagues have had a lot of grief with Heartbeat going split > brain. It seems to really be designed for a pair of machines sitting next > to each other in a rack with a serial link for the heartbeat, rather > servers installed in a pair of machine rooms three miles apart. To be fair to heartbeat, if you're getting unexpected split brain, then you have configured it incorrectly. A 2 node cluster without _extremely_ reliable communication and fencing between the nodes requires a tie-breaker service. This is true of any clustering technology I have ever seen. Heartbeat provides a light-weight quorum service for just this purpose. Of course if you only have 2 sites, and the site with the "extra" vote goes down, you lose the service. Anything else requires 3 sites, or a "meatware" failover decision. -- Carson ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
