[tahoe-dev] detecting weak uploads and share rebalancing Re: Share rebalancing
shawn at willden.org
Sun Oct 11 01:41:09 UTC 2009
On Saturday 10 October 2009 05:36:20 pm Zooko Wilcox-O'Hearn wrote:
> The patch that Kevan has written for #778 would cause weak uploads to
> fail, as you desire, without changing your FEC parameters.
It wouldn't change my FEC parameters? I thought his patch would change the
current parameters to mean servers instead of shares, so I would think that
setting H and N larger than the number of servers in the grid would be a
problem. I have K = number_of_servers.
> the current version of his patch has a problem -- in certain unusual
> edge conditions it could cause a strong upload to fail.
I haven't followed the patch very closely. I guess I should go read about it.
A lot of the terminology in the description assumes knowledge of the code,
though, so my perception is that it would take significant effort to
> > In any case, the more important part of my question was how to fix
> > the present problem, rather than how to avoid it in the future :-)
> Ah, yes. So the process you described sounds like it would work, to
> me, but for immutable files there is an easier way -- just copy the
> share files to other servers. :-)
I could do that, but I'd really like to get the shares to the *right* servers,
per the permuted list, to minimize the likelihood that the repairer ends up
placing shares poorly if the file has to be repaired.
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