As you all are aware, git.wikimedia.org (powered by GitBlit) has been unstable. The root cause is basically that there is insufficient caching mechanisms in place exacerbated by a lack of robust rules for web indexers (Google, Bing, etc).
Currently, the solution is to disallow all indexers from indexing git.wikimedia.org via the robots.txt file (https://git.wikimedia.org/robots.txt). We hope to open up indexing in a more controlled fashion soon.
For now, git.wikimedia.org should be stable for everyday use.
You can follow along with the caching developments on bug 49371: https://bugzilla.wikimedia.org/show_bug.cgi?id=49371
Thanks to Chad and Ariel, especially, who have been working to make sure this is resolved quickly and permanently.
Greg