CentOS - Nov 2008 - Cluster Heart Beat Using Cross Over Cable

Hi,

  I am running two node active/passive  cluster running Centos3 update
8 64 bit on Hp Box with external hp storage connected via scsi. My
cluster was running fine for  last 3 years.But all of a sudden cluster
service keep on shifting (atleast one time in a day )form one node to
another.

 After analysed the syslog i found that  due to some network
fluctuation service was getting shifted.Both the nodes has two NIC
bonded together and configured with  below ip.

My network details:

192.168.1.2 --node 1 physical ip  with  class c subnet (bond0 )
192.168.1.3 --node 2 physical ip  with class c subnet (bond0 )
192.168.1.4  --- floating ip  ( cluster )

 Since it is a very critical and busy server may be due to heavy
network load  some hear beat signal is getting missed  resulting in
shifting of service from one node to another.

So i planned to connect crossover cable for heart beat messages, can
any one guide me  or provide me the link that best explains  how to do
the same and the changes i have to made in cluster configuration file
after connecting the crossover cable.

Regards,

Lingu

lingu wrote:
>  Since it is a very critical and busy server may be due to heavy
> network load  some hear beat signal is getting missed  resulting in
> shifting of service from one node to another.
For automated takeover systems, especially critical ones (tho you can 
argue that any system setup with automatic takeover is critical by 
definition), you should have multiple heartbeat paths. Ethernet, serial 
cable, on shared disk, fibre or whatnot.

Having false takeovers due to missed heartbeat on one set of ethernet 
cards could also likely be missed on another set of cards, even with a 
crossover cable.

Maybe you should investigate alternate paths?

-- 

//Morten Torstensen
//Email: morten at mortent.org
//IM: morten.torstensen at gmail.com

I can't listen to that much Wagner. I start getting the urge to conquer 
Poland.
	-- Woody Allen

>   I am running two node active/passive  cluster running Centos3 update
> 8 64 bit on Hp Box with external hp storage connected via scsi. My
> cluster was running fine for  last 3 years.But all of a sudden cluster
> service keep on shifting (atleast one time in a day )form one node to
> another.
> 
>  After analysed the syslog i found that  due to some network
> fluctuation service was getting shifted.Both the nodes has two NIC
> bonded together and configured with  below ip.
> 
> My network details:
> 
> 192.168.1.2 --node 1 physical ip  with  class c subnet (bond0 )
> 192.168.1.3 --node 2 physical ip  with class c subnet (bond0 )
> 192.168.1.4  --- floating ip  ( cluster )
> 
>  Since it is a very critical and busy server may be due to heavy
> network load  some hear beat signal is getting missed  resulting in
> shifting of service from one node to another.
> 
> So i planned to connect crossover cable for heart beat messages, can
> any one guide me  or provide me the link that best explains  how to do
> the same and the changes i have to made in cluster configuration file
> after connecting the crossover cable.
Hi Lingu,

I realize you're just trying to get this fixed, but what happened on
your network to make an ha pair that has been stable for three years
start getting flakey?

Everything I know about heartbeat comes from
http://www.linux-ha.org/ha.cf.

I'm fairly sure all you need to add to your config is a bcast line. In a
simple setup, "bcast eth0 eth1" will send heartbeats over eth0 and
eth1,
you will probably want "bcast bond0 eth3" depending on your interface
names. Make sure you are also pinging a third host (the subnet's gateway
is a good choice). There was a heartbeat security issue a couple years
ago, you should consider planning to upgrade to a patched version.

Patrick