[tahoe-dev] [tahoe-lafs] #778: "shares of happiness" is the wrong measure; "servers of happiness" is better

[tahoe-lafs]

#778: "shares of happiness" is the wrong measure; "servers of happiness" is
better
--------------------------------+-------------------------------------------
 Reporter:  zooko               |           Owner:  kevan
     Type:  defect              |          Status:  new  
 Priority:  critical            |       Milestone:  1.5.1
Component:  code-peerselection  |         Version:  1.4.1
 Keywords:  reliability         |   Launchpad_bug:       
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Comment(by kevan):

 Okay, I'm updating two patches.

 I updated my tests patch to include a test for the scenario Zooko proposed
 in comment:53. It's not _quite_ ideal (I need to figure out a way to make
 the {{{Tahoe2PeerSelector}}} pop server 0 off the peers list first for it
 to be perfect), but it fails with the current code.

 I also noticed that my {{{_servers_with_unique_shares}}} method in
 [http://allmydata.org/trac/tahoe/browser/src/allmydata/immutable/upload.py?rev=4045
 upload.py] was comparing peerids with things that weren't peerids, so I
 made a minor change to the behavior.txt patch to address that.

 My todo list is basically:

   * Add a test for the scenario I propose in comment:52
   * Design + implement changes to the peer selection algorithm to address
 the scenario in comment:53.

 I welcome any comments.

-- 
Ticket URL: <http://allmydata.org/trac/tahoe/ticket/778#comment:59>
tahoe-lafs <http://allmydata.org>
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