MC ServiceGuard and 4 node cluster

[doris grady]

Hi,
How does failover and heartbeat work within a 4-node cluster...how would crossover cables be arranged....and are they required.

P.S. This thread has been moved from Disk to HP-UX > Serviceguard. - Hp Forum Moderator

[Chan 007]

Hi,

1. Failover will be done how you configure a package.

Try cmviewcl (-v) will give you the output and the behaiviour of your package.

2. Heartbeat will be based on QUORUM calculation.
e.g when all 4 servers are up, the quorum will be

4/4 = 100% - No problem
when One server is lost
3/4 = 75% (Here once it makes itself 75%, then automatically it tunes to 3/3 after the failure of one node) so finally it makes it self 100% (So no reboot/halting is required)
When one more goes after this
it will be 2/3 so with 66% it will be still working..!!!

Whereas if you loose 2/4 (50%) then cluster require a manual reboot

Chan

[Torsten.]

Crossover cables are not required, this is just one out of some solutions. But a good solution for a 2 node cluster. You can use a "normal" LAN connection (switch) for heartbeat. Failover will work as configured, e.g. node 1 and 3 are responsible for package 1, node 1 and 2 for package 2 ... and it is up to you to decide if you need 2 2-node clusters or 1 4-node cluster.

[f. halili · Accepted solution]

For 4 node cluster you will need a quorum server. Crossover cables are for 2 node clusters only.

Cheers,
f. halili