[tor-bugs] #33666 [Circumvention/Snowflake]: Investigate Snowflake proxy failures

[Tor Bug Tracker & Wiki]

#33666: Investigate Snowflake proxy failures
-------------------------------------+--------------------------------
 Reporter:  cohosh                   |          Owner:  cohosh
     Type:  defect                   |         Status:  needs_revision
 Priority:  High                     |      Milestone:
Component:  Circumvention/Snowflake  |        Version:
 Severity:  Normal                   |     Resolution:
 Keywords:                           |  Actual Points:
Parent ID:  #19001                   |         Points:
 Reviewer:                           |        Sponsor:
-------------------------------------+--------------------------------
Changes (by cohosh):

 * status:  needs_review => needs_revision


Comment:

 Replying to [comment:18 dcf]:
 > To me, the 1.B you suggested doesn't match the patch at
 https://github.com/cohosh/snowflake/pull/25. comment:16 makes it sound
 like 1.B is about clients reporting on proxies to the broker, and the
 broker enforcing the limit on proxies; but the pull request looks like the
 proxies noting their own failures and throttling themselves privately, not
 reporting the failure to anyone.
 >
 Whoops. You're right. I meant 1.A in both this comment and the one before
 it >.<

 >  Something to consider instead of discrete thresholds is a more analog
 polling frequency. Something like the additive increase/multiplicative
 decrease of TCP congestion avoidance, say. If a proxy has a failure, it
 multiplies its polling interval by a fixed percentage; if it has a
 success, it subtracts from its polling interval a fixed constant (down to
 some minimum).

 Ah. I like this better actually. The problem with thresholds is that if a
 proxy has a restrictive NAT, then once it succeeds it will start polling
 frequently again right away. With additive or multiplicative increases, we
 also don't need to worry about disabling proxies alltogether just yet.

 I'll work on this and also rip out the disable code for now.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/33666#comment:19>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online