
Improving Server Performance through Better Scheduling - BrandonM
http://www.cs.cmu.edu/~bianca/project_pages/project_sync.html
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BrandonM
Bianca was a faculty candidate here at Ohio State and gave an interesting talk
about a month ago about improving system reliability. The part I found most
interesting was how a small patch to the Linux kernel to change scheduling
gave a remarkable improvement to performance.

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xyzzy
I wonder to what extent this is a statistical artifact rather than a genuine
improvement. For example, if you measure performance as the mean time to serve
each kilobyte, then the proposed scheduler does not increase performance.

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BrandonM
That's true, but what was actually measured was the mean time to serve the
entire request. I think in nearly any usage pattern, this would be the data
point that you would be most concerned with. You want users browsing your
pages to get their pages and small images very quickly, and if they have to
wait a couple seconds for the larger images to finish, or for minutes for
large file downloads, that seems to be the kind of behavior a user would
expect.

What this scheduling algorithm avoids is the case where several people are
downloading large files and other more casual users are having a worse
browsing experience because of that.

