Re: [dhcwg] Load Balancing for DHCPv6

Donald Eastlake <> Sat, 08 September 2012 23:36 UTC

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From: Donald Eastlake <>
Date: Sat, 08 Sep 2012 19:35:47 -0400
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To: Ted Lemon <>
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Subject: Re: [dhcwg] Load Balancing for DHCPv6
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How much of a rush is there on this?

I've sent a message to Brian Carpenter asking if he could run his test
data with Pearson to compare with FNV.

The FNV draft has been presented at a SAAG meeting and the comments
received resolved. I think it is in quite good shape. I just need to
finish up the source code. Maybe this is just the incentive I need :-)

 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
 155 Beaver Street, Milford, MA 01757 USA

On Fri, Sep 7, 2012 at 6:29 PM, Ted Lemon <> wrote:
> On Sep 7, 2012, at 5:37 PM, Donald Eastlake <> wrote:
>> FNV takes a little more effort than Pearson. It also has a smaller
>> footprint in memory. And I believe it will produce statistically
>> better results. What are the relative weights of these or other
>> factors in this case?
> Unfortunately, as far as I can tell neither of the studies you cite compares FNV to Pearson, although the results from Brian Carpenter's study are certainly pretty impressive.    I think more work is worse, smaller footprint probably doesn't matter (this algorithm is being run in DHCP servers, which typically aren't seriously memory-constrained), and statistically better results only matter if it's a pretty big difference, so it's frustrating that we don't have a comparison to the existing algorithm.
> To me, the biggest win of using FNV would be if there were an RFC to refer to, but it looks like this is not quite there yet.   So my conclusion is that I certainly don't oppose using FNV instead of Pearson, but I don't see a strong reason to support it either.