On Fri, Apr 25, 2014 at 7:32 PM, Gergo Tisza <gtisza@wikimedia.org> wrote:

All but the imageinfo call are cached on Varnish for one day. (Caching imageinfo for more than a few minutes would be more problematic as users would expect to see changes to image description etc. immediately.)

Merging filerepoinfo/imageinfo/imageusage/globalusage into a single API call should be possible even on the client side, but it would mean that we cannot cache anything; not sure how that affects server load (I suppose the API has its own caching mechanism, but even that must have some overhead compared to Varnish). Similarly, merging multiple calls to the same API would be possible but would make caching mostly useless.

Making 12 API calls means you run into browser connection limits[1]. The overhead for each discrete request is substantial as well. I strongly suspect that combining the calls would substantially improve real-world user experience, but rather than relying on hunches I'd really like to see a controlled experiment that compares the two approaches. Would it be difficult to make MMV's code choose one or the other approach at runtime?

[1]: http://www.browserscope.org/?category=network