On Thu, Dec 04, 2003 at 06:20:35PM -0800, Martin Stone Davis wrote:
> Toad wrote:
> 
> >m0davis suggested that we should use pSearchFailed (or more detailed
> >stats), despite backoff. The reason we don't do this is that if we did,
> >a node in the RT would get a few queries and then its pSearchFailed
> >would increase, and subsequently it would not be routed to at all for a
> >very long time, because of it's very high estimate. This is the reason
> >that the running averages are not appropriate for QRs and timeouts -
> >because they don't recover. If we did use them, we would have to also
> >have a mechanism to ensure that the nodes were contacted after they
> >ceased to be backed off, DESPITE their bad estimates. This was a
> >significant part of the justification behind instating backoff in the
> >first place.
> 
> Let me try to put my suggestion for reinstating pSearchFailed in 
> context.  Implicit in my derivation of estimate() was that all of the 
> estimators used in the formula were as accurate as reasonably possible. 
>  The worse the estimators, the worse routing will be.  Therefore, it is 
> out of the question to be unrealistically optimistic about new nodes. 
> For a completely new node, we should either use the global estimators, 
> or ask other nodes for estimator data on the it.

I don't see how what you are talking about is relevant to what I was
talking about :)

I oppose using a running average for pSearchFailed specifically because
it would not be accurate - most nodes have longish periods of rejecting
most queries, then recover. But our pSearchFailed would go really high,
and then we wouldn't route to the node.
> 
> I don't know what the objections to this proposal might be.  It suppose 
> some might say that we would not route to new nodes often enough.  But 
> exactly how much is "enough"?
> 
> It might also be objected that we would eventually not route to new 
> nodes if we used global estimators.  But that simply isn't true.  Since 
> global estimators are based on the nodes we actually route to, they are 
> a bit more optimistic than average.  However, for any particular key, 
> the global estimator isn't more optimistic than our best node. 
> Therefore, new nodes would be queried if we got QRs or DNFs in the top 
> "half" of the "specialized" bunch.
> 
> -Martin
> 
> 
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Matthew J Toseland - [EMAIL PROTECTED]
Freenet Project Official Codemonkey - http://freenetproject.org/
ICTHUS - Nothing is impossible. Our Boss says so.

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