Findwise/Hydra — pull request #106 by jwestberg (2012-10-29 13:51:45+00:00)
Title: Implementation of Stage Groups

With the merge of this pull request, it becomes possible to configure hydra stages in groups. All stages in a StageGroup will be run in the same JVM, allowing much greater control of the processes in play in your Pipeline.

A `Pipeline` now contains only `StageGroups` which in turn contain the actual `Stage` objects. As a result, configuring via the Database packages has changed, but old configurations in MongoDB will still function (upon reading a stage that does not belong to a group, a new group matching the name of the stage will be added by the MongoPipelineReader).

StageGroups can contain configurations on the JVM level - such as the jvm installation directory, classpath information etc - while all other configuration stays in the configuration of the specific stage.

Tested to be working within the same jar file as well as with multiple jars :)