Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
> On 02/01/2012 12:38 PM, Lawrence Strydom wrote: >> Hi Felix. >> >> My setup is, supposed to be, fairly straightforward. Two web servers, >> one in production and the second as a hot standby. >> The problem comes in with availabillity of IP addresses though. These >> are hosted servers and the hosting company won't provide more than one >> Live IP per machine. This means I can't use a floating virtual IP which >> fails over to the second node as that would require a third live IP. > You could send node1's IP floating and remove node2's public IP. Add > internal IPs to both machines, so the passive node is reachable by > hopping through the one with the public IP. > Unless, of course, there are network policies in place that forbid such > shenanigans. >> Instead the hosting company provides fail over of the real IP of the >> primary server to the secondary server through their control panel. >> Weird I know but I didn't choose them, just got given the job. Ok so >> now I need data to be synchronous over both servers in case of primary >> node failure so dual primary would make sense as the IP fail over is >> already taken care of and no further action will be required to make the >> data available on the secondary node. > Fair enough. So the answer would probably still be the same: Do use > pacemaker. The easier way will be to just manage DRBD+Apache, or even > DRBD only. However, the production node is selected independently from > pacemaker, which makes for an odd (and error-prone) design. Please note that there are other ISPs that do this as well, and there are solutions for this in place. Like for Hetzner: https://blog.kumina.nl/2011/03/hetzner-failover-ip-ocf-script-part-iii-when-http-attacks/ I've personally set this up already, and it did work nicely. Maybe they can help you, too. Maybe you can adopt this to work for your provider. > Otherwise, you can set up Pacemaker + Fencing + OCFS2 + Dual-Primary and > get away without promotions. But it's more challenging. NO. NO. NO. NOOOOOOOOOOO. NO NO NO NO. NO. NO. NOOOOOOOOOOOOOOOO. http://www.youtube.com/watch?v=qFkjdNeMe3E#t=0m09s I'll say it again: Every time somebody recommends to use Pacemaker with OCFS2, god kills a kitten. So people, please please please only and really only recommend OCFS2 (or GFS) when there are good reasons for it. All the little kittens that survive will be really thankful! I hardly think that this is a valid OCFS2 usage scenario, quite frankly. No offense meant, but introducing another level of complexity in this setup won't do any good. > HTH, > Felix Best regards Martin -- Martin Gerhard Loschwitz Chief Brand Officer, Principal Consultant hastexo Professional Services http://www.hastexo.com/