Prevent multiple Crucible instances connecting to a single database

Problem Definition

Connecting two FishEye/Crucible instances to the same database may lead to various problems:

• Reviews mix file types, clear inconsistancies in stored diff cache
• Reviews cannot be created due to ConstraintViolationException

Suggested Solution

Implement a protection for these cases. Confluence for example provides a Cluster Safety in a Single Node Standalone Instance which prevents a second instance to start up.