There have been various questions asked in the past about object locking and it seems to be unresolved. I needed a mechanism to lock an object for the duration of a user transaction and found that the Community Commons locking mechanism has been removed because it was working in the Application Server and this is no use in a load-balanced architecture. So I have created a fairly simple mechanism that relies on the database to keep track of locks, based on the GUID of the objects. The pattern would be easy to replicate in any project. If anyone is interested, I would be happy to share, as I would appreciate other people's input to validate my design. Also I would like to know whether Mendix are about to publish a new solution to this problem.