Thus spake Karsten Loesing (karsten.loesing@gmx.net):
On Sat, Mar 12, 2011 at 04:57:58PM -0500, Flamsmark wrote:
Have you considered adding more bandwidth scanners? Is the quorum of 3/4 designed to prevent a pair of scanners from being evil, or to ensure that representative sample is used?
My guess is that we should add more bandwidth scanners. The main problem is that the bandwidth scanners are quite resource-intensive in terms of bandwidth (surprise!), RAM, and personal care by the operator. Also, the bandwidth scanner results are tied to a directory authority vote, so the scanner should be run by the directory authority operators themselves or by a person trusted by them.
The requirement of having at least 3 bandwidth scanners running has to do with preventing a single bandwidth scanner from influencing the median. Even if there were 5 or 6 scanners, we'd require at least 3 scanner results before falling back to the relays' self-reported bandwidth.
Yes. We definitely want 5 or 6, but there will be a substantial upgrade to the bw scanner code before we want to do this, I think.
There's a bunch of things that need to improve, most importantly their stability and memory usage, but also their compatibility with the latest sqlalchemy version, rather than some ancient one (or perhaps in addition).
We can technically add them before these code updates, but it should be a bit smoother to do it afterwords.