[tor-dev] CollecTor data: mapping bridge-network-status to bridge-server-descriptor to bridge-extra-info

[Roger Dingledine]

On Wed, Jul 08, 2015 at 07:45:04PM -0700, David Fifield wrote:
> I'm trying to use CollecTor data to find out how much bandwidth is
> offered by different pluggable transports over time. I.e., I want to be
> able to say something like, "On July 1, bridges with obfs3 offered X MB/s,
> bridges with obfs4 offered Y MB/s," etc.

Great!

> I'm having trouble because sometimes, a router digest listed in a
> bridge-network-status document is not found in the same tarball.
[snip]
> Here's an example of where it goes wrong.
> bridge-descriptors-2015-07/statuses/01/20150701-060138-4A0CCD2DDC7995083D73F5D667100C8A5831F16D

Yeah, I'm not surprised it goes wrong, since the descriptor from
0701-06:01 was likely published in the previous month.

> 	However, I did find it in the previous month's tarball,

Yep.

> It seems rare that the bridge-server-descriptor is missing. In the
> 2015-07 tarball, it happened for 5891/477496 relays (1.2%).
[snip]
> How do you handle cases like this? I had a browse through the Onionoo
> source code, but did not quickly understand it. Should I just always
> include the month preceding the earliest month I want to process?

How many of the 5891 cases does that resolve?

--Roger