[tahoe-lafs-trac-stream] [tahoe-lafs] #1395: error doing a check --verify on files bigger than about 1Gbyte

[tahoe-lafs]

#1395: error doing a check --verify on files bigger than about 1Gbyte
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     Reporter:  sickness       |      Owner:  nobody
         Type:  defect         |     Status:  new
     Priority:  minor          |  Milestone:  undecided
    Component:  code-encoding  |    Version:  1.8.2
   Resolution:                 |   Keywords:  memory verify error
Launchpad Bug:                 |
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Comment (by zooko):

 Replying to [comment:12 warner]:
 > Not that it's likely to be the problem here, but we should update that
 claim to be "{{{N/K*S}}} times a small multiple". I think the multiple is
 currently about 2 or 3.

 I would be willing to update these docs to be more precise or more
 correct, but I'm not entirely sure what you want them to say.
 {{{(N/K)*S*3+50KB}}}? (But only for immutable repair.)

 Note that some of the other numbers in there are marked as approximate by
 a preceding tilde {{{~}}}, e.g. [http://tahoe-lafs.org/trac/tahoe-
 lafs/browser/trunk/docs/performance.rst?rev=4910#repairing-an-a-byte-file-
 mutable-or-immutable performance.rst "Repairing an A-byte file"]. Maybe we
 should use the computer science tradition of ignoring constant factors
 which are independent of the variables ({{{K}}}, {{{N}}}, {{{S}}},
 {{{A}}}, {{{B}}}, and {{{G}}}). However, I would rather follow that
 tradition only when the constant factors that we're ignoring are
 sufficiently small that our users will be willing to ignore them too. :-)

 So in short: +0 from me, but you would need to write a patch for
 {{{performance.rst}}} yourself. Your attention to that document would be
 much appreciated by me because I would like for your admirable concern for
 precision in resource usage to be better represented there.

 The pipeline size, which applies only to immutable objects and only to
 uploads, is 50 KB: [http://tahoe-lafs.org/trac/tahoe-
 lafs/browser/trunk/src/allmydata/immutable/layout.py?annotate=blame&rev=4655#L99
 immutable/layout.py WriteBucketProxy].

-- 
Ticket URL: <http://tahoe-lafs.org/trac/tahoe-lafs/ticket/1395#comment:13>
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