[tor-bugs] #9645 [Tor]: Tor client goes berserk downloading microdescriptors forever, if you rm -rf its datadir

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#9645: Tor client goes berserk downloading microdescriptors forever, if you rm -rf
its datadir
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     Reporter:  arma    |      Owner:
         Type:  defect  |     Status:  needs_review
     Priority:  normal  |  Milestone:  Tor: 0.2.4.x-final
    Component:  Tor     |    Version:
   Resolution:          |   Keywords:  tor-client
Actual Points:          |  Parent ID:
       Points:          |
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Comment (by nickm):

 Replying to [comment:5 mr-4]:
 > I am not so keen on either solutions to be honest. Writing to RAM,
 particularly in resource-constrained systems would be very undesirable (I
 use 7 instances of tor, all deployed on such systems).

 Right now, they're left in RAM anyway when the disk write is successful.

 > The "big hammer" fix isn't a solution to me either, though I don't know
 what the implications are if tor doesn't save this new information
 (descriptors?), so I can't really judge what the impact is going to be if
 things are left as they are - without any fix.

 Right now, it's going to hammer on the directory caches.  IMO, if a user
 doesn't have enough disk to save microdescriptors to disk, and they don't
 have RAM to keep them in memory, then they don't have enough resources to
 run Tor.

 > OK, tor will loop endlessly until it can write its descriptors back, but
 what happens if:
 >
 > 1. tor tries limited amount of time (say 60 times) and then doesn't try
 any more (stays with the old descriptors)? or
 > 2. tor does what it is currently programmed to do - loop indefinitely
 until it can write those descriptors (I still can't see why is that bad,
 provided there are no memory leaks)?

 It doesn't do that.  It throws them out, then re-downloads them, which is
 not good for the network.  That's why Roger thinks this needs a fix in
 0.2.4.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/9645#comment:6>
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