[Linux-cluster] RHCS separate datacenter

[Laszlo Beres]

On Thu, Aug 12, 2010 at 8:35 PM,  <rhurst at bidmc.harvard.edu> wrote:

> stretches a 100 inches or a 100 miles.  I think Ana should reveal more about her implementation rather than hearing about yours.  ;)

Cannot agree more :)

> And what part of what I said is "false"?  I didn't say anything that fail-over AND load-balancing were required.  Fail-over can be achieved in numerous ways and without RH supplied tools; the load-balancing is native to Linux using IPVS.  But back to the original question: will Red Hat support ... ?  If you use your OWN fail-over strategy, you OWN it.

It was your statement "RHCS is IPVS" that I felt false.

> Yes, OpenAIS (and likewise the former pulse on RHEL4, sorry for dating myself) is for fail-over which (either) can operate on different LANs.  And to my knowledge and not practical use, the load-balancing (IPVS) can work on different LANs -- if the tunneling option is used.  But my point was that I have not seen any implementation that also maintains IPVS client-session tracking on DIFFERENT LANs (which is NOT a problem if it is on the same physical LAN, like your setup).  It is that last point that has obvious implications on the scope and objectives for those seeking a "supportable" Linux-based solution.

I'm afraid there's still a misunderstanding there - either on my or your side.

Pulse was and is a mechanism to ensure a heartbeat channel between two
ipvs primary and backup routers. Pulse never had anything to do in the
failover cluster core (which is cman in RHEL4, or OpenAIS starting
with RHEL5). cman is not supported to be operated on different
subnets.

> Have a great day!

Rather night here in Europe ;)

-- 
László Béres            Unix system engineer
http://www.google.com/profiles/beres.laszlo