Mesa CI Optimization Could Provide Big Bandwidth Savings

You may recall that earlier this year X.Org/FreeDesktop.org may have to cut CI services for developers over the cloud expenses associated with that continuous integration service for the likes of Mesa, the X.Org Server, and other components. CI usage was leading to a lot of bandwidth consumption so much so that the X.Org Foundation is facing potential ~70k USD cloud costs this year largely from their continuous integration setup.

Since then there has been some work on better optimizing their continuous integration setup with Jenkins and within the latest Mesa Git is some further tuning.

Thanks to the work by Benjamin Tissoires, git pull should now use a lot less bandwidth. Over the past week the Mesa CI setup consumed roughly 1.7TB of bandwidth while with the work by Ben there is better caching of Git trees.

Ben's final numbers were now when the CI runners need a git pull, only around 250KB is needed to download instead of pulling ~280MB of data. This change alone should be a big improvement for their CI setup in conserving bandwidth and in turn saving money for the open-source organization. It's a bit surprising it took this long though for more aggressive caching in their CI setup for such an important project to the Linux desktop.