[tahoe-lafs-trac-stream] [tahoe-lafs] #2059: Increase file reliability against group failure

[tahoe-lafs]

#2059: Increase file reliability against group failure
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 Reporter:  markberger                         |          Owner:
     Type:  enhancement                        |         Status:  new
 Priority:  normal                             |      Milestone:  undecided
Component:  code-peerselection                 |        Version:  1.10.0
 Keywords:  preservation servers-of-happiness  |  Launchpad Bug:
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 Servers of happiness improves share distribution and guarantees a file can
 be recovered for up to n - h node failures. However, if a group of nodes
 fail, servers of happiness makes no guarantees. If I lose all the machines
 in my house, I have no way of knowing whether my other nodes have enough
 shares to reconstruct all my data.

 One way of fixing this is to group a maximum of n - h nodes in a single
 location, but I think that solution is silly because I might not want to
 increase my n or lower my h to meet the requirement. Instead, I should be
 able to organize storage nodes into failure groups and guarantee that a
 subset of those groups can reconstruct the file. Given a set of groups
 with g cardinality, any subset with a cardinality of g - 1 must have k
 shares.

 This is somewhat related to #467, but I think this ticket serves a
 different purpose.

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Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2059>
tahoe-lafs <https://tahoe-lafs.org>
secure decentralized storage