[tahoe-lafs-trac-stream] [tahoe-lafs] #2107: don't place shares on servers that already have shares

[tahoe-lafs]

#2107: don't place shares on servers that already have shares
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     Reporter:  zooko    |      Owner:
         Type:           |     Status:  new
  enhancement            |  Milestone:  undecided
     Priority:  normal   |    Version:  1.10.0
    Component:  code-    |   Keywords:  upload servers-of-happiness brians-
  peerselection          |  opinion-needed
   Resolution:           |
Launchpad Bug:           |
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Comment (by markberger):

 Replying to [comment:13 zooko]:
 >
 > Hm, isn't this true only if that share isn't already provided by another
 server? Or more precisely true only if ''some'' combination of the servers
 already holding shares wouldn't be able to provide the file in just as
 many cases ''without'' the addition of this new share?

 Yes, due to the nature of a maximum matching bipartite graph, the servers
 of happiness value will only increase for shares that have not been placed
 somewhere else. And yes, when a share is placed on a server that already
 contains some nonzero number of shares, the servers of happiness value
 does not increase.

-- 
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2107#comment:16>
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