[Cyberduck-trac] [Cyberduck] #185: Slow SFTP transfers

Cyberduck trac at trac.cyberduck.ch
Fri Nov 12 16:00:38 CET 2010

#185: Slow SFTP transfers
    Reporter:  wout.mertens@…          |        Owner:  dkocher      
        Type:  enhancement             |       Status:  closed       
    Priority:  high                    |    Milestone:  4.0          
   Component:  sftp                    |      Version:  3.5          
    Severity:  major                   |   Resolution:  fixed        
    Keywords:                          |     Platform:  Mac OS X 10.6
Architecture:  Intel                   |  

Comment (by caeies):

 Replying to [comment:66 dkocher]:
 > Replying to [comment:62 caeies]:
 > > Ok reading you code, I think that the main problem is that you are
 waiting for the ACK before continuing to send data, while openSSH just
 send stuff as fast as it can until he fills the queue, then check for ACK
 when the sent queue is filled ...
 > I don't see how the patch attached changes this behaviour. It will still
 toggle between writing and reading the status.

 Yes, but after ''parallelism'' requests only. So it doesn't wait for the
 network latency just after sending the first request and so on ... it will
 read back the answer only after the 64th requests, so when the server
 starts to reply to the requests and that the requests are back to the

 Anyway, the main problem of this patch is the lasts 64th requests that
 aren't checked at the end of the download.

 Hope I'm clear


Ticket URL: <http://trac.cyberduck.ch/ticket/185#comment:68>
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