[tor-dev] Proposal 275: Stop including meaningful "published" time in microdescriptor consensus
nickm at alum.mit.edu
Mon Feb 27 00:36:24 UTC 2017
On Sun, Feb 26, 2017 at 6:17 AM, teor <teor2345 at gmail.com> wrote:
>> On 25 Feb 2017, at 03:25, Nick Mathewson <nickm at torproject.org> wrote:
>> Filename: 275-md-published-time-is-silly.txt
>> Title: Stop including meaningful "published" time in microdescriptor consensus
>> Author: Nick Mathewson
>> Created: 20-Feb-2017
>> Status: Open
>> Target: 0.3.1.x-alpha
>> 4. Proposal
>> As an interim solution: We should add a new consensus method number
>> that changes the process by which Published fields in consensuses are
>> generated. It should set all all Published fields in the consensus
>> should be the same value. These fields should be taken to rotate
>> every 15 hours, by taking consensus valid-after time, and rounding
>> down to the nearest multiple of 15 hours since the epoch.
> I wonder what this does to relays that have a broken clock.
> Is there any particular reason you chose 15 hours, rather than, say,
> 18 hours (the interval at which relays re-post descriptors), or 12 hours
> (the re-post interval - the consensus lifetime - 3 hours skew allowance)
I chose 15 because it was approximately in the middle of 12 and 18.
But 12 might be more conservative.
>> 5. Analysis
>> With the longer-term solution in place, and all published times held
>> constant permanently, the compressed diff sizes were uniformly at
>> least 56% smaller.
>> With this in mind, I think we might want to only plan to support the
>> longer-term solution.
> Do you mean "only implement" the longer-term solution?
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