[tor-bugs] #4486 [Analysis]: Research: should N23 actually help in practice?

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#4486: Research: should N23 actually help in practice?
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 Reporter:  arma                     |          Owner:       
     Type:  task                     |         Status:  new  
 Priority:  normal                   |      Milestone:       
Component:  Analysis                 |        Version:       
 Keywords:  performance flowcontrol  |         Parent:  #4506
   Points:                           |   Actualpoints:       
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Comment(by arma):

 Replying to [comment:9 robgjansen]:
 > The downloaders do not "give up" unless the socks connection is closed
 by the other end. Although, I now realize that its probably smart to have
 the client "give up" so as to avoid knocking it out of the simulation
 because its download hung. Doesn't Tor kill the AP connection if it can't
 get a circuit by a deadline?

 Yes. But if it gets a circuit and starts getting bytes, it will never stop
 until it gets an 'end' cell from the other side. From the Tor client's
 perspective, it's got a TCP connection open and the other side has chosen
 not to send data lately, which is fine.

 So if a significant fraction of the clients are stalling, that's either a
 Tor bug (e.g. "for some reason the end cell gets lost") or a simulation
 bug (no example guesses yet there). But I guess if the client is no longer
 adding load to the network, it's not necessarily the case that lots of the
 clients are stalling -- it could be a few of them right at the beginning,
 and then they just disappear from the simulation after that. That case
 would especially influence the rest of the simulation since the client
 load has changed.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/4486#comment:10>
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