[tor-relays] managing bandwidth quotum

[Roger Dingledine]

On Tue, Aug 26, 2014 at 06:43:04PM +0200, Kees Goossens wrote:
> A question on how to manage a bandwidth quotum of my internet provider.
> I run a non-exit relay on a hosted server with 1000 GB bandwidth per month.
> 
> In essence, should I 
> A- only set the AccountingMax, and let the relay figure out the RelayBandwidthRate & RelayBandwidthBurst by itself
> B- set the AccountingMax, and set RelayBandwidthBurst to whatever the provider will allow (much higher than the average rate)
> C- set the AccountingMax, and set RelayBandwidthRate to the average rate (quotum/31 days), and optionally set RelayBandwidthBurst
> D- only set the RelayBandwidthRate to the average rate, and hope that I don?t go too much over my quotum

https://www.torproject.org/docs/faq#LimitTotalBandwidth suggests
setting accountingmax and then setting the relaybandwidth* options
to run for at least half your allocated time.

So for 1000GB per month, assuming you mean 500GB each way per month,
or 16GB each way per day, it suggests

AccountingStart day 0:00
AccountingMax 16 GBytes
RelayBandwidthRate 320 KBytes
RelayBandwidthBurst 5000 KBytes

Alas, 320 KBytes isn't very much these days, so you should maybe
experiment with other options, like raising it higher.

> This could perhaps be rephrased as:
> - is it better to offer a high bandwidth for part of the month and then hibernate, or 
> - should I offer a lower average bandwidth for the whole month?

Usually we suggest the latter, so relays can have more stability. But
your average would indeed be quite low then (thus probably not
attracting much use compared to the many faster relays).

> Details:
> I?ve set ?AccountingMax 450 GB? with the appropriate accounting start (conservative, since I log in occasionally too).
> 450 GB / 31 days => 168 KB / sec average 
> Setting ?BandwidthRate 168 KB? seems to severely underutilise the relay.
> Setting ?BandwidthRate 1000 KB?, to force usage of the relay, uses the relay bandwidth at a much larger rate (2670 KB/s consensus weight), and will cause hibernation after ~25 days.  

Hibernation after ~25 days sounds great, since you're up for most of the
month and also you're using most of your bandwidth. I wonder if the FAQ
should be updated? Or if you should make a wiki page with more examples,
and we can link to it from the faq?

--Roger