[tahoe-lafs-trac-stream] [tahoe-lafs] #2107: don't place shares on servers that already have shares
tahoe-lafs
trac at tahoe-lafs.org
Sun Dec 1 21:26:00 UTC 2013
#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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Changes (by zooko):
* cc: warner (added)
* keywords: upload servers-of-happiness => upload servers-of-happiness
brians-opinion-needed
Comment:
Thanks, markberger!
Replying to [comment:10 markberger]:
> Servers of happiness is not a boolean value. It is a measurement of how
effectively shares are distributed. For each distinctive server with any
nonzero number of shares, the servers of happiness value increases by 1.
In terms of how we model the problem, the servers of happiness value is
len(E) where E is the set of edges used in the maximum matching bipartite
graph of shares to servers.
>
> In terms of your example zooko, when you place a share on one server,
you are constructing an edge between that share and that server in the
bipartite graph. Therefore, the servers of happiness value is 1.
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?
Okay, so I ''think'' what this means is that sickness and amontero and me
would be satisfied with Rule 3:
''Rule 3: "Don't put a share on a server unless doing so would increase
the Servers-of-Happiness-Level."''
Does everyone agree that this is a good rule to enforce on an uploader or
repairer? markberger? daira? sickness? amontero? brian?
--
Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/2107#comment:13>
tahoe-lafs <https://tahoe-lafs.org>
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