Re: [9fans] Venti over DHT

[Eric Van Hensbergen <ericvh@gmail.com>]

On Oct 20, 2009, at 7:53 AM, Enrico Weigelt wrote:
>
> I've also done some bits of works in that area
> (nothing usable yet ;-o), but with different
> requirements:
>
> * storage near to the user (at least local mirrors)
> * equal data should get equal score (even w/ encryption)
> * automatic removal of stale blocks -> garbage collection
> * efficient also on small data blocks
>
> Especially the distributed GC together w/ encryption turned out
> not be quite trivial ;-o
> On the one hand we need things like timestamps, on the other hand
> we need to trace the tree structures w/o decryption.
>
> So I added several block types: eg. blob (payload data) and inode
> (holding the tree). blobs are encrypted w/ their score, thus
> reading takes scores (outer for retrieval, inner for decryption).
> inodes have an public area, listing just the outer scores and an
> encrypted one holding the inner scores. The tree formed by inodes
> doesn't necessarily has to be fully balanced, so incremental writes
> with special heuristics for preventing unncessary writes are possible.
>
>
> If someone likes to hear more about this, just let me know :)
>

I'm interested.  Particularly in the multi-layer caching/mirroring and
the encryption/same-score details.

        -eric