Performance analysis

Now, let us look at things a bit more practically.
After all the expected reality is always different from the actual one! Even though one's definitions of reality itself may vary.

Lets look at the performance of boa. So we decided. Historically, boa has been bench marked with ab and zb. We decided to go ahead with the Apache Benchmark.

A simple command:
   ab -n 1000 -c 500 http://10.0.0.1:12345/file.txt
   ab -n <total number of requests> -c <concurrency level> http://<ip addr>:<port>/<location>
and lots of time, is what we required

Repeatedly performing the same on epoll implementation gave us quite surprising results. No, not surprising to the extent of select performing better, but both of them performing at about the same level.

               Time taken

Concurrency Level

epoll vs select

When the lines coincide so perfectly, you wonder if this was the result expected! But Alas! It was not. We expected epoll to perform better, not just better much better!

But theoretically, we did expect select and epoll to perform just about the same for a lesser number of concurrent connections. Upon consulting an expert for advice on these matters, we were told that a concurrency level of 250 is peanuts!

Planning to try out a concurrency of a 1000 clients we wondered how loaded our machines would be.
So we decided to find out!