[tahoe-lafs-trac-stream] [Tahoe-LAFS] #661: Dynamic share migration to maintain file health

[Tahoe-LAFS]

#661: Dynamic share migration to maintain file health
----------------------------+----------------------------------------------
     Reporter:  mmore       |      Owner:
         Type:              |     Status:  closed
  enhancement               |  Milestone:  undecided
     Priority:  major       |    Version:  1.3.0
    Component:  code-       |   Keywords:  repair preservation availability
  encoding                  |
   Resolution:  duplicate   |
Launchpad Bug:              |
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Changes (by daira):

 * status:  new => closed
 * resolution:   => duplicate


Old description:

> Dynamic share repair to maintain file health. based on the following
> features
> already exist in Allmydata-Tahoe1.3 we can improve automatic repair:
>
>  1. Foolscap provides the knowledge of the alive nodes.
>
>  2. Verification of file availability can be delegated to other node
> through
>     read-cap or a verify-cap without security risk.
>
> The proposed auto repair process:
>
>  1. Using memory-based algorithm, because client know where the file
> shares
>     exist so we can keep tack of alive file shares, for simplicity we
>     consider that share availability from its node availability.
>
>  2. repair process triggered automatically from the repairer, repair
>     responsibility has many technique based repair cost ; network
> bandwidth
>     and fault tolerant.
>
>  3. time out , we can use lazy repair technique to avoid node temporary
> node
>     failure, i.e waiting for a certain time before repair process starts.
>
>  4. reintegration, using memory-based repair technique remembering failed
>     storage servers, who come back to life, will help in reducing Tahoe
> grid
>     resources such as network bandwidth and storage space.
>
>  5. repairer, selection of repair responsibly takes many issues into
>     consideration: security , repairer location , repairer resources.

New description:

 Dynamic share repair to maintain file health. based on the following
 features
 already exist in Allmydata-Tahoe1.3 we can improve automatic repair:

  1. Foolscap provides the knowledge of the alive nodes.

  2. Verification of file availability can be delegated to other node
 through
     read-cap or a verify-cap without security risk.

 The proposed auto repair process:

  1. Using memory-based algorithm, because client know where the file
 shares
     exist so we can keep tack of alive file shares, for simplicity we
     consider that share availability from its node availability.

  2. repair process triggered automatically from the repairer, repair
     responsibility has many technique based repair cost ; network
 bandwidth
     and fault tolerant.

  3. time out , we can use lazy repair technique to avoid node temporary
 node
     failure, i.e waiting for a certain time before repair process starts.

  4. reintegration, using memory-based repair technique remembering failed
     storage servers, who come back to life, will help in reducing Tahoe
 grid
     resources such as network bandwidth and storage space.

  5. repairer, selection of repair responsibly takes many issues into
     consideration: security , repairer location , repairer resources.

--

Comment:

 Duplicate of #543.

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Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/661#comment:5>
Tahoe-LAFS <https://Tahoe-LAFS.org>
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