[CentOS] simple load balancing/failover for OWA

Wed May 28 08:18:03 UTC 2008
Amos Shapira <amos.shapira at gmail.com>

On Fri, Apr 4, 2008 at 11:36 PM, Matt Shields <mattboston at gmail.com> wrote:
> On Fri, Apr 4, 2008 at 9:03 AM, Ruslan Sivak <rsivak at istandfor.com> wrote:
>> David Hrbác wrote:
>> > Ruslan Sivak napsal(a):
>> >
>> > > We are building an exchange cluster with two front end Outlook Web
>> Access servers.  We would like to at least have some sort of failover, and
>> prefereably load balancing for them.
>> > >
>> > > Russ
>> > >
>> >
>> > Russ,
>> > take a look at
>> http://httpd.apache.org/docs/2.2/mod/mod_proxy_balancer.html
>> > David
>> > _______________________________________________
>> >
>>  Yes, that what I was thinking.  However, I believe these servers also run
>> smtp, pop3, imap,etc, so I don't think Apache can handle all of those..
> LVS handles all protocols.  It can do any port and UDP or TCP.  It
> supports different types of balancing Round Robin (rr), Weighted Round
> Robin (wrr), Least Connections (lc), Weighted Least Connections (wlc).
>  It can do sticky sessions, so if OWA doesn't like when you go from
> server 1 to server 2, LVS will keep the user stuck to one server.
> Plus a ton of other features.  Give it a shot.

I'm trying to setup a couple of LVS servers on CentOS 5 and hitting
I've been googl'ing around the docs (it mostly all gets back to
for a few days now but can't get it to work. It sometimes work
temporarily but very quickly a few fail-overs made things totally

One issue I suspect that might be in my way to success is that the two
servers (I'm trying to use same two servers both as ldirectors and
real servers) are assigned to two separate /28 networks, BUT the
virtual rack (from ThePlanet) allows both of them to be assigned
addresses from each other's network so I assigned an address from the
correct network on an alias on the other server (eth0:0).

Does anyone have a working example for this on CentOS 5? The docs I
found so far are mostly generic and talk a lot about ancient kernel
versions like 2.0, 2.2 and 2.4.

I subscribed to the lvs-users mailing list but I'm not sure how active it is.