[tor-relays] Need help: High capacity exit relay does not get traffic

[Aaron]

On Sun, Oct 7, 2012 at 5:46 AM, tor-admin <tor-admin at torland.me> wrote:
> Hi,
>
> I am operating two 1 GBit/s servers which host 7 exit nodes. One server is
> located in GB with
>
> torland1
> https://atlas.torproject.org/#details/4E377F91D326552AAE818D5A17BC3EF79639C2CD
>
> torland2
> https://atlas.torproject.org/#details/332895D092C2524A3CDE8F6E1498FFE665EBFC34
>
> torland1 is configured to run at maximum bandwidth, torland2 runs trottled to
> ensure not to exceed the 100TB contractual traffic limit. The nodes on this
> server get traffic as expected and are at the top of the Blutmagie Tor Status
> http://torstatus.blutmagie.de/index.php?SR=Bandwidth&SO=Desc.
>
> The second server is located in RO and hosts
>
> torland3
> https://atlas.torproject.org/#details/E5DB403858511BB166405E4C43776D933A7B86D6
>
> torland4
> https://atlas.torproject.org/#details/E0D2F8B2A18516A5C935477B06048D7BD2E7EC57
>
> torland5
> https://atlas.torproject.org/#details/D2F1745C11843BC5AF09CB9D4027AD2BE5F1B20A
>
> torland6
> https://atlas.torproject.org/#details/43F9022028F8AB0F7420F702CB079DF0CA0C80E3
>
>
> The configuration for the GB and RO nodes is:
>
> Nickname TorLandX
> ORPort 443
> DirPort 80
> Address a.b.c.d
> ORListenAddress  a.b.c.d
> DirListenAddress a.b.c.d
> OutboundBindAddress a.b.c.d
>
> RelayBandwidthRate  30 MBytes  # max 30
> RelayBandwidthBurst 100 MBytes  # max 100
>
> MaxOnionsPending 250
>
> NumCPUs 4
>
> On both servers AES-NI is used by openssl.
>
> Although the server in RO has the same configuration, same operating system
> and a similar hardware, it does not get traffic as the server in GB. At the
> moment Atlas shows for torland3-6 only an advertised bandwidth rate of less
> the 3 MB/s. The GB node torland1 shows more than 30 MB/s.
>
> In order to test if there are any traffic limits I did several speed tests by
> doing up and downloads of a large 4GB iso image.
>
> Downloading simultaneously with 10 curl instances from different debian
> mirrors I measured around 1 GBit/s. To measure upload I stored the debian 4GB
> iso image on the webserver of the RO server and used curl on the GB server to
> download it from RO. The maximal measured upstream speed on the RO server was
> around 750 Mbit/s. Therefore I looks for me as there are no traffic limits
> inplace by my ISP or their upstream.
>
> One of the servers operated by Torservers.net is located in the same data
> center and runs wau, gorz and sofia at high speed.
>
> I am wondering why the directory authorities only measure such a small
> fraction of the available bandwidth for the RO nodes. Because I am paying
> personally for the server I would like to get most out of the server. Can
> someone who runs a tor authority please help me to understand what is the
> reason for the low observed bandwidth.
>
> Thanks,
>
> Torland
>
> _______________________________________________
> tor-relays mailing list
> tor-relays at lists.torproject.org
> https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays

I am not a directory authority. Have you taken a closer look at the
configuration of the Tor exits wau or sofia?
They are run by torservers.net -- see this page in particular.
https://www.torservers.net/wiki/setup/server#high_bandwidth_tweaks_100_mbps

I might guess that TCP window scaling and latency could be a factor.

--Aaron