Using Perforce Counters To Watch For Changes

By default Parabuild uses polling to detects changes in codebases under Perforce control. This is a preferable configuration because it allows for configuring builds without any changes on the P4 side. Yet for an overloaded Perforce server that handles considerable number of files polling could be a concern because it adds load to the server.

Parabuild addresses this issue by allowing watching a counter that contains the latest change list number for a project codeline. Using a counter reduces load on the Perforce server. To activate this feature a Perforce administrator needs to set up a trigger on the Perforce server. The trigger should update the counter to the latest change list number for the project's depot path.

The screen shot below shows a build configuration that makes use of watching a P4 counter.