[tahoe-dev] [tahoe-lafs] #1170: does new-downloader perform badly for certain situations (such as today's Test Grid)?

[tahoe-lafs]

#1170: does new-downloader perform badly for certain situations (such as today's
Test Grid)?
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     Reporter:  zooko         |       Owner:                                           
         Type:  defect        |      Status:  new                                      
     Priority:  critical      |   Milestone:  1.8.0                                    
    Component:  code-network  |     Version:  1.8β                                     
   Resolution:                |    Keywords:  immutable download performance regression
Launchpad Bug:                |  
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Comment (by zooko):

 Replying to [comment:28 zooko]:
 > This seems promising. It sounds like you might think that the slowdown
 of 1.8.0c2 vs. 1.7.1 on the current Test Grid might be due to one server
 being used to serve two shares in 1.8.0c2 when two different servers would
 be used—one for each share—in 1.7.1.

 Okay this does appear to be happening in at least one of the slow v1.8.0c2
 downloads attached to this ticket. I looked at
 attachment:1.8.0c2-r4698-run-106-down-0.html and every request-block in it
 (for three different shares) went to the same server -- nszizgf5 -- which
 was the first server to respond to the DYHB (barely) and which happened to
 be the only server that had three shares. So at least for that run,
 Brian's idea that fetching blocks of different shares from the same server
 is a significant slowdown seems to be true.

-- 
Ticket URL: <http://tahoe-lafs.org/trac/tahoe-lafs/ticket/1170#comment:30>
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