Use case: I want to connect to all the AIX servers. I want to connect to just the external AIX servers.
AFAICT, with the current cluster config file, I would have to do something like this:
clusters = AIX AixInternal AixExternal
AIX = AixInternal AixExternal
AixInternal = alpha beta gamma
AixExternal = delta epsilon zeta
If I now want to connect to all the servers running Apache, internal and external, I would have to create an Apache list, which contains all the Apache hosts, or I would have to create subdivision of AixInternal/External, eg. AixExternalApache. You end up with lots of redundacy and subdivisions.
I would rather reverse the syntax and use attribute tags, e.g.
alpha: AIX apache internal
zeta: AIX apache external
upsilon: Linux apache mysql
then do something like "cssh :apache,aix,external".