Why so little bandwidth used?

[Roger Dingledine]

On Wed, Feb 16, 2011 at 10:52:41AM -0500, Steve Snyder wrote:
> My Tor router, named ThunderGodTor, seems to be using too little bandwidth.
> 
> I have configured the bandwidth limit as 100KB and the burst at 200KB.
>At http://torstatus.asprion.org/ i see confirmation of this configuration,
>plus an Observed bandwidth of roughly 119KB.  All these values are well
>within my total network bandwidth.
> 
> Check out the Router Detail page at http://torstatus.blutmagie.de/
>for my stats.  It shows an average of about 35KB - 40KB with rare peaks
>at 100KB.  This confirms my observation that Tor is not actually using
>the 100KB limit I specified.

Actually, I think it's the opposite -- you *are* using the limits you
specified. Saying "bandwidthrate 100KB" doesn't mean you'll be spiked at
100KB per second all the time. If you are, that means one or more clients
(probably more than one) are bottlenecked at you. That's actually a bad
thing for Tor performance -- always being at your max bandwidth is a sign
either of users doing bulk downloading through you (leaving nothing for
other users), or way way too many web-browsing users for the available
relays. So we should be really happy that relays aren't pegged at their
max bandwidth all the time:
http://metrics.torproject.org/performance.html

In part I suspect this trend is due to the recent influx of
relays. Another part is due to Mike Perry's "bandwidth authority"
measurement scripts that try to push traffic through each relay and
compare the performance they get to the relay's peers (that is, relays
that advertise the same bandwidth rate). For example, on
http://freehaven.net/~arma/moria1-v3-status-votes
you can see the votes for ThunderGodTor:
w Bandwidth=102 Measured=81
w Bandwidth=102 Measured=109
w Bandwidth=102 Measured=124
w Bandwidth=102 Measured=95
which results in a low-median weighting of 95 in the networkstatus
consensus:
http://128.31.0.34:9131/tor/status-vote/current/consensus
So your relay is right on target compared to its peers.

If you want to raise the overall number of bytes you provide to the Tor
network without increasing your long-term average, you should raise
your bandwidthburst. Or you could just raise your bandwidthrate. :)
If the total number of bytes you use in the month is a worry, check out
AccountingMax in the Tor man page.

Hope that helps. And thanks for running a relay!
--Roger