This document is a work-in-progress and represents a very early state of the Pods design. Significant aspects are not documented, though we expect to add them in the future. This is one possible architecture for Pods, 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.
In our Pods architecture proposal we plan to share all admin related tables in GitLab. This allows simpler management of all Pods in one interface and reduces the risk of settings diverging in different Pods. This introduces challenges with admin pages that allow you to manage data that will be spread across all Pods.
There are consequences for admin pages that contain data that spans “the whole instance” as the Admin pages may be served by any Pod or possibly just 1 pod. There are already many parts of the Admin interface that will have data that spans many pods. For example lists of all Groups, Projects, Topics, Jobs, Analytics, Applications and more. There are also administrative monitoring capabilities in the Admin page that will span many pods such as the “Background Jobs” and “Background Migrations” pages.
We will need to decide how to handle these exceptions with a few possible options:
- Move all these pages out into a dedicated per-pod Admin section. Probably
the URL will need to be routable to a single Pod like
/pods/<pod_id>/admin, then we can display this data per Pod. These pages will be distinct from other Admin pages which control settings that are shared across all Pods. We will also need to consider how this impacts self-managed customers and whether, or not, this should be visible for single-pod instances of GitLab.
- Build some aggregation interfaces for this data so that it can be fetched from all Pods and presented in a single UI. This may be beneficial to an administrator that needs to see and filter all data at a glance, especially when they don’t know which Pod the data is on. The downside, however, is that building this kind of aggregation is very tricky when all the Pods are designed to be totally independent, and it does also enforce more strict requirements on compatibility between Pods.