[bind10-dev] a couple thoughts about performance testing of servers

[Jerry Scharf]

Hi,

About 4 years ago I did a round of nameserver performance testing. I 
just wanted to add a couple thoughts from the sidelines based on this 
experience. Use them as they help you.

Expecting every query to be answered gives really low numbers for a 
server. A server will start to drop queries at as little as 10% of full 
query throughput. So we need to be clear what we are testing to. Having 
some marketing background, I always use the test that gives the highest 
number. :)

On the server I was testing, there was a predictable point at about 
1-1.5% query drop rate where the total throughput stopped going up and 
most additional queries were dropped. I called that the peak performance 
for the test. I also had to do some nasty things to decide exactly how 
fast to send queries at. I had a tool (I have no code now) that would 
send bursts of queries at intervals. This allowed for much higher query 
output rates than timing between each query. I had a pstat logging to a 
file for the whole time of the run on both machines, it helped to 
understand many the things as I tuned up the tests.

I assume we are testing out of cache for the primary numbers. It's the 
only fair way to compare the apples and oranges of BIND 9 and 10 (or any 
other server for that matter.)

hope that helps,
jerry