benchmarking 3.1.0 and 3.0.1

[Bryan Call]

I ran some benchmarks on the 3.0.1 release and the 3.1.0 release with different options on and off. This benchmark was done with 1 client, 1 proxy, and 3 origin servers. The servers are 12 core (24 hyper-threaded) boxes and are the beefiest I could get a hold of. The response was only a 1 byte response, so that I wouldn't make the NIC a bottleneck.

There are a couple things to note in the benchmark results:

1. There is a huge impact in performance in 3.0.1 and 3.1.0 having
   logging on and only proxying to the origin server.  Turning off
   logging increases the performance by 185%.  I think there can be
   some large performance gains to be won here.
2. There was a huge performance decrease from 3.0.1 to 3.1.0 with just
   turning off the cache and only proxying to the origin.  3.1.0 is
   only performing at 14% of what 3.0.1 is.  Turning off shared
   sessions removes this decrease in performance, so some of the work
   that Leif is doing might resolve this.  I am going to benchmark his
   patch today.
3. http_load (the client) is making ~5x more connections on 3.1.0 then
   3.0.1.  Traffic Server might be closing the client connections, but
   I didn't look into this.
4. There are some cores in 3.0.1 and 3.1.0 only when logging is turned
   off.  I believe there might be a race condition and can only been
   seen at high loads, so it shouldn't been seen too often.



--
-Bryan

Details of the hardware and the client commands are in the spreadsheet (open/libreoffice). Overall I think the numbers are pretty good.

ats benchmark.ods
Description: application/vnd.oasis.opendocument.spreadsheet