[tor-bugs] #32129 [Circumvention/Snowflake]: Increase Snowflake proxy poll interval to 300 s

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#32129: Increase Snowflake proxy poll interval to 300 s
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     Reporter:  dcf                      |      Owner:  (none)
         Type:  enhancement              |     Status:  new
     Priority:  Medium                   |  Milestone:
    Component:  Circumvention/Snowflake  |    Version:
     Severity:  Normal                   |   Keywords:
Actual Points:                           |  Parent ID:
       Points:                           |   Reviewer:
      Sponsor:                           |
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 The Snowflake proxies are polling the broker more frequently than
 necessary for the number of clients we have. The broker reports about 500
 proxies currently, which at the current poll interval of 20 s, is 25
 polls/s.

 At the [http://meetbot.debian.net/tor-meeting/2019/tor-
 meeting.2019-10-17-16.59.log.html anti-censorship meeting today] we talked
 about increasing the interval to 300 s, which would still give us an
 expected time-to-proxy-assignment of less than 1 s.

 {{{
 17:41:02 <dcf1> A few weeks ago I tailed the log of the broker, and
 requests were coming in furiously.
 17:41:23 <dcf1> Lately those particular log lines have been removed, so
 it's not as apparent, but according to https://snowflake-
 broker.bamsoftware.com/debug there's 500 proxies,
 17:41:39 <dcf1> and with a poll interval of 20 s, that's 25 incoming proxy
 requests per second.
 17:41:42 <arma2> i liked the idea of having the broker tell each snowflake
 when to come back
 17:41:59 <dcf1> Something on the order of 1 or 2 per second is probably
 adequate.
 17:42:07 <cohosh> arma2: serna has started on that ticket
 17:42:14 <cohosh> i agree
 17:42:23 <dcf1> arma2: yeah that's #25598, serna ran into some trouble
 with that.
 17:42:42 <cohosh> we have metrics of how many idle proxies we have:
 https://metrics.torproject.org/collector/archive/snowflakes/
 17:42:57 <cohosh> and it is orders of magnitude more than the the number
 of client matches
 17:43:31 <dcf1> Anyway, I think an interval of around 300 seconds would be
 workable.
 17:43:37 <cohosh> sounds good
 }}}

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/32129>
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