Usage metrics and logging for Git clones

Problem to solve

Clone is an important special case for Git where large amounts of data is transferred and there are interesting opportunities to optimize clones, but we don't know how often clones occur, now the type of clones (single branch, shallow, partial...)

Further details

We should collect clone statistics for evaluating clone performance and adoption of different features.

Proposal

Add logging so that we can detect when a clone is happening, and what class of clone it is.

We should consider how we can collect this data from self hosted instances too so that we can monitor adoption and usage of partial clone.

Links / references