I want to simplify the rollback handling a bit.
Right now there are a number levels at which a user can specify that they want rollback in case of failure:
1) At the level of an individual action within a larger set of actions (Example: my plan deploys 3 apps, and if #2 fails I want it rolled back, but don't roll back #1 or #3)
2) Within a set of actions that apply to a server. If any action in the set fails, all roll back. For a standalone server, this is specified with the withGlobalRollback() call shown above.
And, for the domain controller use case only (irrelevant to standalone server case):
3) For a set of servers in a server group, whether failure on one or more trigger rollback across the group.
4) For a set of servers groups to which the same set of changes is being applied, whether failure of one server group triggers rollback of the others. (Example: multiple servers running same app, divided into multiple server groups to facilitate a rolling upgrade)
5) For a large complex plan where different sets of changes are applied to different server groups, whether failure of one set triggers rollbacks of other sets. (Example: in a multi-tier topology, roll out some deployments to server-groups in tier A, and then roll out different deployments to servers in tier B.)
I want to get rid of 1). It complicates the implementation and I don't think it adds a lot of benefit. If people want different behavior for different deployments, they can be executed separately without much trouble.