Mirror updates appear to run too frequently

Here's what I did:

  1. Installed GitLab 9.3.5 EE
  2. Added a project (https://github.com/wearehive/project-guidelines), configured it for mirroring

Now I see:

Mirror update for root/project-guidelines was scheduled.
Mirror update for root/project-guidelines started. Waiting duration: 0
Mirror update for root/project-guidelines successfully finished. Update duration: 0}.
Mirror update for root/project-guidelines was scheduled.
Mirror update for root/project-guidelines started. Waiting duration: 0
Mirror update for root/project-guidelines successfully finished. Update duration: 1}.
Mirror update for root/project-guidelines was scheduled.
Mirror update for root/project-guidelines started. Waiting duration: 0
Mirror update for root/project-guidelines successfully finished. Update duration: 1}.
Mirror update for root/project-guidelines was scheduled.
Mirror update for root/project-guidelines started. Waiting duration: 0
Mirror update for root/project-guidelines successfully finished. Update duration: 1}.
Mirror update for root/project-guidelines was scheduled.
Mirror update for root/project-guidelines started. Waiting duration: 0
Mirror update for root/project-guidelines successfully finished. Update duration: 1}.
Mirror update for root/project-guidelines was scheduled.
Mirror update for root/project-guidelines started. Waiting duration: 0
Mirror update for root/project-guidelines successfully finished. Update duration: 1}.
Mirror update for root/project-guidelines was scheduled.
Mirror update for root/project-guidelines started. Waiting duration: 0
Mirror update for root/project-guidelines successfully finished. Update duration: 1}.
Mirror update for root/project-guidelines was scheduled.
Mirror update for root/project-guidelines started. Waiting duration: 0
Mirror update for root/project-guidelines successfully finished. Update duration: 1}.
Mirror update for root/project-guidelines was scheduled.
Mirror update for root/project-guidelines started. Waiting duration: 0
Mirror update for root/project-guidelines successfully finished. Update duration: 1}.

This seems overzealous?

We should probably also starting adding timestamps to all Rails.logger calls.

/cc: @tiagonbotelho, @DouweM, @pcarranza