Healing isn't directly part of this change. What is is random reinsertion of successfully downloaded data; one in every 200 successful requests will result in a reinsertion.
On Sun, Aug 06, 2006 at 10:45:29PM +0200, John B?ckstrand wrote: > >So, if the originating host happens to be the closest for the given key in > >the entire network (which, in a network of a few hundred or at most few > >thousand nodes and small file chunks is going to happen quite often), it > >won't be stored at all, despite the insert seemingly completing > >succesfully? > > > >And of course, since nodes sometimes leave from the network or change > >their position, even popular content's availability will deteriorate > >steadily as it's permanently stored on less and less datastores. > > Not really, with healing, which toad has implemented: every successful > download will then help make the file more accessible to others by > inserting the failed blocks. If some nodes are now offline that received > the original data, new nodes, which are online now and closest, will > receive it now and make the data doubled if the original node returns. > > This combined with ECC should work fine, even in a network with lots of > churn and lost data. > > This, I think, has a slight bias towards storing popular data on nodes > with high availability, even more so than today. So popular data should > "always" be around, not dependent on node X, which has the crucial "last > block", being online. Less popular data though might require waiting > around for nodes to pop up with the data on them. > > Healing really feels like a missing piece of the puzzle, I always > thought straight LRU should work pretty badly, but my guts tell me thats > not the case with healing in the mix. The problem was, I felt, that > blocks that were accessed from successful downloads were worth exactly > the same as an access for an incomplete file which is no longer > completely in the network, and this could potentially help keep old > unusable data in the stores, modulo people getting tired of requesting > unsuccessful data. > > --- > John B?ckstrand > _______________________________________________ > Tech mailing list > Tech at freenetproject.org > http://emu.freenetproject.org/cgi-bin/mailman/listinfo/tech > -- Matthew J Toseland - toad at amphibian.dyndns.org Freenet Project Official Codemonkey - http://freenetproject.org/ ICTHUS - Nothing is impossible. Our Boss says so. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: Digital signature URL: <https://emu.freenetproject.org/pipermail/support/attachments/20060807/35def953/attachment.pgp>
