[bind10-dev] an interesting take on how to do stats

[Jerry Scharf]

Hi,

Paul Ebersman tossed an idea to me on the side and after thinking about 
it I wanted to send it out to the list. This is me paraphrasing and 
expanding his idea.

His basic suggestion was aimed at getting around the challenge of adding 
more stats and not slowing down the server path. He asked what if the 
stats engine got all its data from a pcap tap of the raw traffic and the 
query processing didn't have to do anything related to stats.

At first glance, this seemed like quite a bit of duplicated processing 
(packet unmarshalling, context switching, etc.) and would slow things 
down even more. But on a multicore system, this could run almost 
completely independent of the BIND 10 server, using it's own memory 
space and not impacting the query processing "fast path" at all.

The upsides I see:
         takes code out of the "fast path"
         concentrates all logging work in a separate area, better modularity
         ideal for high end systems with many cores/processors

The downsides I see:
         doesn't work on systems that don't have pcap
         could make life worse on busy servers with 1-2 cores
         requires root to set up pcap tap
         possibly duplicates code

what do people think?

jerry