[Linux-cluster] dependencies between services

[Greg Forte]

Is it possible to set up dependencies between cluster services?  That 
is, I have services A, B, C, and D.  B, C, D can't run unless A is 
running, but B, C, and D are all independent of each other and I want to 
be able to control them individually, i.e. be able to start/stop (or 
rather, enable/disable) each without affecting the others.  I know I 
could define them as dependent resources all in the same service, but 
then I can't have that independence between B, C, and D ... unless I'm 
missing something.

Of course, the fall-back approach is that I just define each as a 
separate service and make the init scripts for B, C, and D check to see 
that A is running (probably via a clustat | grep "A's name" kludge), but 
I'm hoping there's a better way, since this is ugly as hell and will 
only work if the service consists entirely of init script resources.

-g

Greg Forte
gforte at udel.edu
IT - User Services
University of Delaware
302-831-1982
Newark, DE