Deletion of groups is a generally desired feature we’d like to support in Gerrit. However, there seem to be two major behaviors/modes depending on host admin/owner preferences: 1) Remove a group without keeping a Git ref to it to reduce the number of Git refs on the Gerrit server. 2) Remove a group but keep its complete audit and add an audit entry for the group deletion.
In core Gerrit, we can’t implement 1) without offering 2) by default as existing host admins/owners might rely on core Gerrit’s audit for groups to keep track of all modifications. Enabling traceless group deletion without explicit consent from these persons would likely result in negative surprises.
To save audit log within the core Gerrit implementation, one approach is to save all audit records in a new branch called refs/meta/deleted-group or store them in a data directory if necessary. The core Gerrit implementation already has established structures and functions for manipulating group data, such as rename and group creation, which makes it more readable and coherent to include the delete group functionality within the core. Implementing group deletion as a core feature also offers scalability benefits as it requires less maintenance compared to an external plugin. By reusing existing core functions and maintaining all group-related operations in one place, the system becomes easier to manage in the long run.
Implementing 2) is more effort, though, and even more so if want to offer 1) and 2) both inside of core Gerrit. The proposer of the design wishes to support just 1). Hence, we recommend to implement 1) in core Gerrit.