[freenet-dev] Why Freenet is so SLOW! / Finding data

[Matthew Toseland]

On Monday 10 December 2007 23:40, Robert Hailey wrote:
> 
> On Dec 10, 2007, at 1:10 PM, Matthew Toseland wrote:
> 
> > IMHO the next step forward is simply to log location changes and  
> > display them
> > either on the location page or on a subpage, or as CSV data (or  
> > perhaps
> > through SNMP) so it can be graphed externally. Maybe for the node's  
> > peers as
> > well as itself. Are you interested in doing some data collection  
> > code? Lets
> > discover whether there actually is a problem with location drift  
> > before we
> > try to solve it ...
> 
> I think that it should be observable with a few more datastore stats.  
> Specifically the datastore location, and the location of succeeding  
> requests.

Not enough on its own, IMHO that doesn't give us proof of cause, only proof 
that something is broken.
> 
> A quick implementation is attached. It only accounts for what is in  
> the datastore since-launch (but shows a percent thereto), and takes up  
> several megabytes more of memory to track the location of the  
> datastore/cache in a running average.

It is possible to iterate the keys and build a histogram. It'll take a while 
but you don't have to do it often.
> 
> If we are leaving our stores behind, I would predict that for many  
> nodes (running suffecient to have meaningful stats) that the  
> 'storeDist' value may become arbitrary. And if it approaches the  
> 'furthestSuccess' value the store is "left-behind"; whereas the  
> cacheDist will maintain approx. the same (once reliable).

IMHO we need the histogram, or at least a measure of spread, not just an 
average key.
> 
> Do you want this in the trunk? I don't think that I have the time to  
> do much data collection.

Your diff is empty. Might be a problem on my end though.
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