[tor-bugs] #18113 [Tor Launcher]: Dynamically allocate clients to default Tor Browser bridges of a certain type

[Tor Bug Tracker & Wiki]

#18113: Dynamically allocate clients to default Tor Browser bridges of a certain
type
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     Reporter:  isis          |      Owner:  brade
         Type:  enhancement   |     Status:  new
     Priority:  Medium        |  Milestone:
    Component:  Tor Launcher  |    Version:
     Severity:  Normal        |   Keywords:  tbb-bridges tor-launcher
Actual Points:                |  Parent ID:
       Points:                |    Sponsor:
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 Right now, if I've understood correctly, a client wanting to use Tor
 Browser's default bridges tries the first bridge of whichever bridge type
 they've selected, then the second, then third, etc.  This is suboptimal
 because it leads to:

  1. The first default bridge gets hammered with many clients.
  2. The other bridges possibly aren't getting enough clients.
  3. The clients will only move to using a different default bridge if the
 ones previously tried are already overloaded, which means that a client
 waits longer to bootstrap Tor.
  4. The clients who do end up all sharing the first default bridge are
 probably having a bad time because they're all sharing the bandwidth and
 CPU capacities of one over-stressed bridge.

 Can we just pick a random number, mod the total number of default bridges
 for that type, and use that bridge?  Is there anything smarter we could
 do?  Would we need to store state somewhere on which ones were previously
 tried?

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/18113>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
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