This document is a work-in-progress and represents a very early state of the Cells design. Significant aspects are not documented, though we expect to add them in the future. This is one possible architecture for Cells, and we intend to contrast this with alternatives before deciding which approach to implement. This documentation will be kept even if we decide not to implement this so that we can document the reasons for not choosing this approach.
Classification of all endpoints is essential to properly route requests hitting the load balancer of a GitLab installation to a Cell that can serve it. Each Cell should be able to decode each request and classify which Cell it belongs to.
GitLab currently implements hundreds of endpoints. This document tries to describe various techniques that can be implemented to allow the Rails to provide this information efficiently.