On 3 Oct 2015, at 19:09, Dhalgren Tor dhalgren.tor@gmail.com wrote:
Was going to wait a few days before reporting back, but early results are decisive.
The overload situation continued to worsen over a two-day period, with consensus weight continuing to rise despite the relay often running in a state of extreme overload and performing its exit function quite terribly. ... The bandwidth measurement system now looks like a secondary issue. The big problem is that Tor daemon bandwidth throttling sucks and should be avoided in favor of Linux kernel rate-limiting where actual bandwidth exceeds bandwidth allocated to Tor, whatever the motivation. TCP is much better at dealing with congestion than the relay internal limit-rate logic.
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You might find Rob Jansen's KIST paper interesting reading - it is about making Tor aware of kernel buffers. (Currently, Tor doesn’t know what happens after it writes data to the socket.)
http://www.robgjansen.com/publications/kist-sec2014.pdf http://www.robgjansen.com/publications/kist-sec2014.pdf
Tim
Tim Wilson-Brown (teor)
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