I'm working on creating a set of MongoDB heat templates. I would like to ensure that as Mongo replica set's come and go, they are placed on seperate hosts.

The some older documentation makes it sound like you can specify a group name like "MongoDB-ReplicaSets" and have the scheduler figure out what instances are tagged that way. Some newer documentation makes it sound like you must specify the set of all instances you want it on different hosts from. Which is it? The group name only is much better then needing to know all the instances, which I'm not sure I have access to.

It is also unclear, how I would specify that I want the GroupAntiAffinityFilter and not the GroupAffinity filter in the template. What is the correct nova hint for this?

Maybe there is a better way to do this too. Any suggestions?

Thanks, Kevin