[tor-bugs] #28624 [Core Tor/Tor]: Should we remember dormant state on restart?

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#28624: Should we remember dormant state on restart?
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     Reporter:  arma          |      Owner:  (none)
         Type:  enhancement   |     Status:  new
     Priority:  Medium        |  Milestone:
    Component:  Core Tor/Tor  |    Version:
     Severity:  Normal        |   Keywords:
Actual Points:                |  Parent ID:
       Points:                |   Reviewer:
      Sponsor:                |
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 One of the core ideas of #2149 was for Tor to remember its dormancy across
 restarts. As of the finishing of #2149, Tor will go dormant 24 hours after
 startup if it's seen no activity -- but if you start it again, it'll be
 active for 24 hours again. So people who restart their computers, or their
 Tor-including apps, will continue putting load on the Tor network.

 So I am opening this ticket to not forget that second piece of it.

 The first question is around the engineering side: when we go dormant, do
 we write that fact into our state file? And when we change our mind, I
 guess we clear it? Do we also write it when the controller commands us to
 go dormant? I guess yes.

 The second question is about how thorough we want to be. Specifically, if
 we're expecting that people will restart their Tor, what about people who
 never leave their Tor going for a full 24 hours? Those people will never
 switch to a dormant state. Is that ok? The fix would be to record "partial
 progress towards going dormant" in the state file, which is kind of ugly
 but also doable.

 The third question is around how to handle it when we start up and the
 state file says we were dormant. Continuing to stay dormant seems like the
 clear right behavior -- because after all, we can wake up and start
 bootstrapping if we actually get an application level request. But I guess
 that means we don't even try to bootstrap? Are there controller apps like
 Tor Launcher and Nyx that wait for the 100% bootstrap message and tell you
 that your Tor is broken if it doesn't happen? Is there something we can
 give those apps instead that will satisfy them that Tor is "acting as
 intended"? Is there some simple "connect to a relay and do a handshake
 with it once" thing that we can do instead on startup, to satisfy
 ourselves that Tor *could* work if we wanted it to? Or should we stay
 totally isolated from the network when we start up in dormant state?

 I think some of these are ux questions, and answering them might be easier
 if we pick a couple of specific use cases for dormant mode. Here are two:

 (1) What if some linux distro includes a Tor client package by default,
 and users can configure their apps to use it but many users don't. In that
 case we'd have thousands or millions of Tor clients installed but not
 usefully using the Tor network. And our primary goal there would be to
 make those Tors go totally quiet after a while. This was the original
 motivation for #2149.

 (2) ...I was going to use an example here of Tor bundled with an app, like
 Brave or Briar, but I think in this case the app should be responsible for
 making Tor behave politely to the Tor network.

 So I think use case (1) is the one to focus on, and that also simplifies
 the ux questions.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/28624>
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