[tor-relays] Why can't I see more traffic? (is my banana too weak?)

[Farid Joubbi]

It seems as if Cpu1 is almost idle most of the time.
Cpu0 is somewhere between 5 and 20.
This is a rather high snapshot:

%Cpu0  : 17.2 us,  2.0 sy,  0.0 ni, 79.5 id,  0.0 wa,  0.0 hi,  1.3 si,  0.0 st
%Cpu1  :  2.4 us,  0.3 sy,  0.0 ni, 97.3 id,  0.0 wa,  0.0 hi,  0.0 si,  0.0 st

I have had the guard flag before.
Maybe I lost it since I rebooted twice and changed ISP a bit more than a week ago.

The IP address does not change unless I reboot or release the current address manually

I used to have 250Mbit/s downstream and 10Mbit/s up with my old ISP.

How does the algorithm that checks the bandwidth work?
Does anyone else reading this run a Banana Pro, Raspberry or similar hardware with better results than me?

Regards,
Farid

________________________________________
From: Roman Mamedov <rm at romanrm.net>
Sent: 03 September 2016 17:14
To: Aeris
Cc: Farid Joubbi; tor-relays at lists.torproject.org
Subject: Re: [tor-relays] Why can't I see more traffic? (is my banana too weak?)

On Sat, 03 Sep 2016 16:53:25 +0200
Aeris <aeris+tor at imirhil.fr> wrote:

> > Could it be that it is due to the quite slow hardware, even though I know
> > that it is able to push more traffic?
>
> Yep, surely.
>
> You currently push 3Mbps of traffic, which is correct for this kind of hardware.
> All "cheap" hardware (raspi, banana, olimex, pine…) suffer of the fact they
> don’t have crypto hardware acceleration and do software encryption. And so is
> very slow (10-100× factor) even compared to low end amd64 CPU with AES-NI
> extension.

According to 'openssl speed aes-128-cbc' the Allwinner A20 CPU in Banana Pro is
capable of about 25 MBytes/sec in AES performance. While that won't translate
1:1 into Tor performance, as Farid noted in his case the CPU isn't being a
bottleneck, with only 10-20% CPU load observed.

@Farid,

> According to top the CPU hovers around 10-20% most of the time.

I wonder is it 20% across both cores, which could be 40% of one core (since
Tor is not multithreaded enough), and at least somewhat closer to not being
practically idle. Can you launch 'top' and press '1' there to check?

Also seems unclear why it didn't get the guard flag for so long, does your
public IP address change from time to time? Or do you turn the relay off and
on for whatever reason.

--
With respect,
Roman