[tahoe-lafs-trac-stream] [Tahoe-LAFS] #268: implement CHK download helper

[Tahoe-LAFS]

#268: implement CHK download helper
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     Reporter:  warner         |      Owner:  warner
         Type:  enhancement    |     Status:  new
     Priority:  major          |  Milestone:  undecided
    Component:  code-encoding  |    Version:  0.7.0
   Resolution:                 |   Keywords:  upload-helper download
Launchpad Bug:                 |
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Changes (by zooko):

 * keywords:  helper download => upload-helper download


Old description:

> The upload-specific helper described in #116 is insufficient to achieve
> all
> the properties we're hoping for. The helper as originally envisioned in
> that
> ticket was specifically for uploading CHK files: it did not encompass
> downloading files (since there's no bandwidth benefit for those), nor did
> it
> include mutable files (since by our SDMF rules, these files are small and
> the
> bandwidth of them isn't too much of a burden).
>
> To prevent the clients from making connections to all storage servers, we
> need a helper that will also mediate CHK downloads and mutable uploads
> and
> downloads. I'm making a separate ticket for this since it's more work
> than
> I'd originally realized. I think I can still get it done in the original
> schedule.
>
> Zooko and I have talked about the need or lack of need for this
> connection-minimization. It may be the case that minimizing connections
> is
> not all that important, at least with a reasonable number of clients. So
> it's
> possible that we'll want the #116 upload-only helper to get us
> resumability
> and 1x uploads, but not the all-purpose helper described in this ticket
> to
> get us minimal connections and isolation between clients and storage
> servers.

New description:

 The upload-specific helper described in #116 is insufficient to achieve
 all
 the properties we're hoping for. The helper as originally envisioned in
 that
 ticket was specifically for uploading CHK files: it did not encompass
 downloading files (since there's no bandwidth benefit for those), nor did
 it
 include mutable files (since by our SDMF rules, these files are small and
 the
 bandwidth of them isn't too much of a burden).

 To prevent the clients from making connections to all storage servers, we
 need a helper that will also mediate CHK downloads and mutable uploads and
 downloads. I'm making a separate ticket for this since it's more work than
 I'd originally realized. I think I can still get it done in the original
 schedule.

 Zooko and I have talked about the need or lack of need for this
 connection-minimization. It may be the case that minimizing connections is
 not all that important, at least with a reasonable number of clients. So
 it's
 possible that we'll want the #116 upload-only helper to get us
 resumability
 and 1x uploads, but not the all-purpose helper described in this ticket to
 get us minimal connections and isolation between clients and storage
 servers.

--

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Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/268#comment:8>
Tahoe-LAFS <https://Tahoe-LAFS.org>
secure decentralized storage