topic Re: a shared HeartBeat network ? in Operating System - HP-UX

a shared HeartBeat network ?

Francois LAURENT — Wed, 28 Apr 2004 09:09:05 GMT

Hi all,

Is there any problem to have 2 DIFFERENTS CLUSTER heart beat on the same network ?

Heart beat runs on broadcast mode, isn't it ? So how the 2 different clusters could dissociate his own heart beat if the 2 heart beat are on the same network ?

At this time, this network is a heart beat dedicated network for one cluster, the network team want to use it for the heart beat of an other cluster too.

Hope that question is not so stupid ...

Francois

Re: a shared HeartBeat network ?

harry d brown jr — Wed, 28 Apr 2004 09:12:42 GMT

I'm not sure what kind of cluster you have, or if it is a problem, but if it is, then have them just create two vlans (virtual lans).

live free or die
harry

Re: a shared HeartBeat network ?

Stefan Farrelly — Wed, 28 Apr 2004 09:12:58 GMT

The hearbeat for an SG cluster is simply an IP address - normally its on a separate network and uses something like a 192.x.y.z range. We have a separate network for our SG heartbeats and we run multiple SG clusters on it - each SG cluster has a different hearbeat IP address so there is no possible conflict. Works fine.

Re: a shared HeartBeat network ?

Sanjay_6 — Wed, 28 Apr 2004 09:15:43 GMT

Hi,

There is no problem is you have multiple cluster heartbeats on the same network / subnet.

The heartbeats are identified using their cluster name and node name. So you can have multiple cluster heartbeats on the same subnet.

Hope this helps.

Regds

Re: a shared HeartBeat network ?

Jeff Schussele — Wed, 28 Apr 2004 09:19:34 GMT

Hi Francois,

1) No - no problem at all. We do it all the time & have had a dozen or more clusters on the same subnet.

2) No - heartheats use DLPI packets from MAC to MAC. They do not broadcast. They transmit on layer 2 - the Link layer.

3) As stated in #1 - this is perfectly acceptable.

HTH,
Jeff

Re: a shared HeartBeat network ?

Francois LAURENT — Wed, 28 Apr 2004 09:22:36 GMT

Thank all for the reactivity and the precision of answers ...
;-)

Re: a shared HeartBeat network ?

Steven E. Protter — Wed, 28 Apr 2004 09:34:03 GMT

I would pay attention to the timeout in the cluster configuration for the heartbeat.

While a shared heartbeat lan is no problem, if the lan becomes congested for a long enough period of time, the race to the lock disk or quorum server starts and nodes may start to TOC.

Thats why a lot of people have their own little private lans for the heartbeat. Then you just have to make sure nobody unplugs the hub or switch.

Having a second heartbeat on a second NIC can mitigate the effects of congestion on your cluster.

SEP