topic Re: implementing package priority in a SG cluster in Operating System - HP-UX

implementing package priority in a SG cluster

Jdamian — Mon, 20 Aug 2007 03:53:20 GMT

Hi

In my cluster, one of the nodes has a lower capacity (weak node). Therefore I must limit the number of packages running at the same time on that node. The limit is 1.

This issue forces to assign priorities to the three packages of the cluster in order that a higher priority package IS ALLOWED to throw out a lower priority package from the weak node.

Is there any trick of the configuration parameters (besides customizing control scripts) to achieve this behaviour on that weak node ?

Thanx in advance

Re: implementing package priority in a SG cluster

Luk Vandenbussche — Mon, 20 Aug 2007 04:08:45 GMT

Oscar,

Have you checked the failover_package and the failback_policy parameters

http://docs.hp.com/en/B3936-90117/ch06s01.html#cacdjhfd

Re: implementing package priority in a SG cluster

Jdamian — Mon, 20 Aug 2007 05:29:48 GMT

"Starting in Serviceguard A.11.17, a package can have dependencies on other packages"

But my ServiceGuard version is A.11.14...

I'll have to edit the control scripts

Re: implementing package priority in a SG cluster

whiteknight — Mon, 20 Aug 2007 05:33:39 GMT

Hi Oskar,

Not sure if you check this doc out.
Good documents on setting the Package order.

http://www1.itrc.hp.com/service/cki/docDisplay.do?docLocale=en&docId=emr_na-c00941165-3

WK

p/s: please assign point

Re: implementing package priority in a SG cluster

Luk Vandenbussche — Mon, 20 Aug 2007 06:41:51 GMT

There are also options for SG 11.14

http://docs.hp.com/en/B9903-90012/ch04s07.html

Re: implementing package priority in a SG cluster

Stephen Doud — Mon, 20 Aug 2007 08:29:23 GMT

Serviceguard doesn't have a mechanism to limit the number of packages on a node to prevent overload. You will have include this ability in the package control script.
The previous document recommended is a good starting point.

Be advised that the latest version of Serviceguard - A.11.18 (which only runs on 11.23 and newer) has a package dependency and priority feature.
Details are available in the latest Managing Serviceguard manual at
http://docs.hp.com/en/ha.html#Serviceguard

Re: implementing package priority in a SG cluster

Doug O'Leary — Mon, 20 Aug 2007 09:59:51 GMT

Hey

As far as I know, you'll have to edit the control scripts. We've done something similar at my client site with no ill effects.

There are any number of clever ways to do this; we have a simple 2-node cluster so it was an easy if statement checking to see if the hostname matched the weak node and if the unwanted package is running to stop it.

Remember, the control scripts are exactly that - scripts. Read through them and edit them to have them do what you need. Just remember to take backups. I usually check mine into RCS.

HTH;

Doug

Re: implementing package priority in a SG cluster

Jdamian — Tue, 21 Aug 2007 01:52:16 GMT

:-(