Don't be fooled by the 99% figure. It says in 2011 the figure wasn't much different. Well that was a bit surprising to me because when I was using Borg in 2011

Don't be fooled by the 99% figure. It says in 2011 the figure wasn't much different. Well that was a bit surprising to me because when I was using Borg in 2011 it didn't feel that way. Borg is vast. Unimaginably vast. Any engineer can start a job in the free tier for a personal web server in minutes, all the way up to saturating 100,000 cores to process some dataset. You can browse cluster job lists forever and never reach the bottom. 1% of jobs is still a huge number of different jobs. The "hogs" are going to be jobs like web search serving, indexing and related, logs processing etc. The "mice" are going to be the long tail of jobs. Remember that this sort of paper presents Borg as a kind of exemplar of what large cluster systems look like, but as you already observe, that's not really true. Borg is really unique to Google and Google is really unique. In particular due to the personalities of its founders and its financial position Google has a massive long tail of products and web sites that don't see much usage, or see decent usage by non-Google standards but which gets lost in the noise of search, ads, YouTube etc. So the hogs vs mice phenomenon is telling us more about the nature of Google and how it does projects than something fundamental about job scheduler systems.