[tahoe-lafs-trac-stream] [tahoe-lafs] #1653: mutable-retrieve should accept good shares from servers with bad shares

[tahoe-lafs]

#1653: mutable-retrieve should accept good shares from servers with bad shares
--------------------------+----------------------------
 Reporter:  warner        |          Owner:
     Type:  defect        |         Status:  new
 Priority:  major         |      Milestone:  eventually
Component:  code-mutable  |        Version:  1.9.0
 Keywords:                |  Launchpad Bug:
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 retrieve.py is currently rather punitive when it detects corrupt shares:
 it stops using *any* shares from the same server. This doesn't have much
 effect when there are plenty of servers and the shares are spread thinly,
 but in small personal grids, a single corrupt share could disqualify
 enough shares that the retrieve fails.

 I think this behavior was copied from the odld immutable downloader. The
 new immutable downloader doesn't do this: it treats each share
 independently.

 To fix this, {{{_mark_bad_share}}} and {{{_remove_reader}}} should remove
 just the one share from {{{self.remaining_sharemap}}}, instead of all
 shares with the same server. We also need to look for other calls to
 {{{_remove_reader()}}}, since I think there may be some which *are*
 supposed to stop all shares from the same server.

-- 
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1653>
tahoe-lafs <https://tahoe-lafs.org>
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