[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 mr-4):

 Replying to [comment:6 nickm]:
 > Right now, they're left in RAM anyway when the disk write is successful.
 Ah, OK. So tor has them in memory anyway, but occasionally tries to write
 them to disk. I take it the information written to disk is only
 usable/needed when tor starts the next time, is that correct?

 If so, then it makes perfect sense for tor to hold the "write" bit until
 it is capable of doing it and issue warnings every 6 hours or so (together
 with the HEARTBEAT message).

 > > 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.
 Got it! You are quite right, that is undesirable. Given the above, I think
 tor should keep them in RAM (as it does that anyway), try to write them at
 regular intervals to disk and issue warnings at regular (but not very
 frequent!) intervals.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/9645#comment:7>
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