`gitaly_commit_raw_diffs` feature causes certain commit pages to timeout
Zendesk: https://gitlab.zendesk.com/agent/tickets/79479
Gitaly Conversation: gitaly#222 (closed)
Profiler HTML screenshot
User reported that prior to us deploying 9.3 to GitLab.com, a commit diff would display fine. After the deploy, the page started timing out. I used app.get on the Rails console and found that the page does load but it takes almost 10 minutes. @lbot and I ran the gitlab-profiler against the URL and noticed it was taking a lot of time on Gitlab::GitalyClient::DiffStitcher. This was released in 9.3.
We asked @eReGeBe to temporarily disable the gitaly_commit_raw_diffs feature on GitLab.com. We found that the commit diff displayed within 2-3 seconds. This seems to confirm that Gitaly is the hangup here.
Edited by Drew Blessing