[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
---------------------------------+-----------------------------------------
     Reporter:  zooko            |      Owner:
         Type:  enhancement      |     Status:  new
     Priority:  normal           |  Milestone:  undecided
    Component:  code-            |    Version:  1.10.0
  peerselection                  |   Keywords:  upload servers-of-happiness
   Resolution:                   |
Launchpad Bug:                   |
---------------------------------+-----------------------------------------

Comment (by daira):

 Replying to [comment:7 zooko]:
 > Well, no, that doesn't make sense ''either''. Because suppose you have
 K=3, N=6 and there are 6 servers. Well, putting a share on the first
 server will not increase the happiness level! It will be 0 both before and
 after placing that one share.

 No, it will be 1.

 It was intentional that the definition of happiness distinguishes between
 robustness levels less than K, even though none of them are sufficient for
 the file to be recoverable (this was an advantage of the maximum matching
 formulation over the "number of servers, the survival and correct function
 of which will guarantee that your file is available" definition that
 preceded it; see [ticket:778#comment:162]).

-- 
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2107#comment:8>
tahoe-lafs <https://tahoe-lafs.org>
secure decentralized storage