ServiceGuard Package Dependencies

[Bruce Owen Lee]

I need to shutdown several packages on another node before a package from yet another node starts (it uses the same mount points) on that node. Can I use package dependencies to do this? I other words, pkg A fails on node 1 and fails to node 2. Node 2 has pkg's C, D and E running and need to be halted before pkg A starts on node 2. How do I do this?

BTW: HP-UX 11.31 w/SG 11.18 Integrity SuperDome

[Steven E. Protter]

Shalom,

For simplicity, I would build a single package that does multiple things.

Example.

If daemonA and daemonB must run on the same system, they should be in the same package.

There is nothing in Service Guard that prevents you from calling a script that starts two services.

That would be my approach.

SEP

[Greg Vaidman · Accepted solution]

Bruce,
I used to implement such functionality in earlier versions of MCSG with code such as the following in the package start script (running before the LVM stuff in the script):

cmviewcl -n `hostname` -p pgkC | grep -i running &&
cmhaltpkg -n `hostname` -p pkgC

(repeat for pkgD & pkgE)

I'm not in front of an MCSG box now, so please check my syntax, but I think it's pretty close.

[Bruce Owen Lee]

Thanks Greg, that did the trick. BTW: the -n and -p options are mutually exclusive in SG 11.18 it worked well enough with just the following:

cmviewcl -p Prod_cup1 | grep running && cmhaltpkg -p Depl_usp1

I placed the code just before the volume group activation in the "start" section of the control script.

[Bruce Owen Lee]

See last posting for solution.

[Greg Vaidman]

Bruce,
Be careful with that syntax - without the check that the package is running on a specific node, you could be shutting down packages pkgC, pkgD & pkgE running on another node. You may need to do extra parsing of the output if the -n and -p options are indeed mutually exclusive.
--Greg

[Duncan Edmonstone]

Whilst the items mentioned will work, I susepct the "correct" way to do this in 11.18 is using package dependencies and package priorities that are available with modular packages:

http://docs.hp.com/en/B3936-90122/ch04s08.html#cihfgeaj

I haven't tried this myself yet, but it should be possible to setup the configuration you require with no special start/stop code (unfortunately all the examples are for dependencies on packages being *running*, not on them being *down*)

HTH

Duncan