Somewhat OT: Clustering and HA

[Vlad Mazek]

I pieced mine out of a few guides but there is an easier way to do this now
(assuming you're in RHEL / CentOS world) as Redhat developed a GUI for HA.
It's called Piranha:
www.*centos*.org/docs/5/html/Virtual_Server_Administration/ch-lvs-*piranha*-
VSA.html

You can get the RPMs from DAG and the process is pretty simple (at least
mine is). I use direct path. On the load balancer just modify the
/etc/rc.d/ha/lvs.cf to setup your load balancer and the virtual servers.

serial_no = 132
primary = 1.2.3.10
service = lvs
backup_active = 0
backup = 0.0.0.0
heartbeat = 1
heartbeat_port = 539
keepalive = 20
deadtime = 20
network = direct
debug_level = NONE
monitor_links = 0
virtual mailscanner {
     active = 1
     address = 1.2.3.5 eth0:1
     vip_nmask = 255.255.255.0
     port = 25
     use_regex = 0
     load_monitor = none
     scheduler = wrr
     protocol = tcp
     timeout = 20
     reentry = 30
     quiesce_server = 0
     server mailscanner1 {
         address = 1.2.3.1
         active = 1
         weight = 1
     }
     server mailscanner2 {
         address = 1.2.3.2
         active = 1
         weight = 1
     }
}

So here is the idea, your system runs on 1.2.3.10 and you're going to be
pointing the MX to 1.2.3.5 which will then deliver mail down to the actual
mailscanner real servers 1.2.3.1 and 1.2.3.2; Just start pulse and you're
done.

Each node needs a loopback interface with the address of the virtual server
and 255.255.255.255 subnet mask.
/etc/sysconfig/network-scripts/ifcfg-lo:1
DEVICE=lo:1
IPADDR=1.2.3.5
NETMASK=255.255.255.255
ONBOOT=yes
NAME=loopback

Some more junk for sysctl.conf (comment out packet forwarding):

net.ipv4.conf.all.arp_ignore = 1
net.ipv4.conf.eth0.arp_ignore = 1
net.ipv4.conf.all.arp_announce = 2
net.ipv4.conf.eth0.arp_announce = 2
net.ipv4.ip_forward = 1

Hope that helps (and hope you want to replicate exactly what I have
otherwise there is reading involved).. :)

-Vlad

On 2/27/08, Alex Neuman <alex at nkpanama.com> wrote:
>
>
> On Feb 27, 2008, at 4:04 PM, Vlad Mazek wrote:
>
> > Keep in mind that if you have more than 4 MX records in round robin
> > the lookup will only return four, throwing the load balancing a bit
> > out of skew.  Linux HA with lvs is dead easy to configure and can do
> > quite a bit with cheap hardware.
>
>
> Can you please direct me to a good "howto" or "cookbook" on Linux HA?
> I've looked around and most are either too specific or outdated.
>
>
> --
>
> MailScanner mailing list
> mailscanner at lists.mailscanner.info
> http://lists.mailscanner.info/mailman/listinfo/mailscanner
>
> Before posting, read http://wiki.mailscanner.info/posting
>
> Support MailScanner development - buy the book off the website!
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.mailscanner.info/pipermail/mailscanner/attachments/20080228/c5bf18b8/attachment.html