Sometimes requesting the diffstat endpoint can cause 555 or 504 status code

Issue Summary

Sometimes requesting the diffstat endpoint can cause the operation to fail with a 555 or 504 status code due to performance issues.

Steps to Reproduce

 This can only be reproduced under certain specific circumstances, not all requests will fail.

1. Request the diffstat endpoint

Expected Results

No errors and a 2xx status code are returned.

Actual Results

A 555 - Unable to respond in time or a 504 Gateway Time-out error is returned.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available. 
In some cases, retrying the operation at a different time will work.