http_load runs multiple http/https fetches in parallel, to test the
throughput of a web server.  However unlike most such test clients,
it runs in a single process, so it doesn't bog down the client
machine.

You give it a file containing a list of URLs that may be fetched,
a flag specifying how to start connections (either by rate or by
number of simulated users), and a flag specifying when to quit
(either after a given number of fetches or a given elapsed time).
There are also optional flags for checksums, throttling, and progress
reports.

Sample run:

% http_load -rate 2 -seconds 300 urls
591 fetches, 8 max parallel, 5.33606e+06 bytes, in 300 seconds
9028.87 mean bytes/connection
1.97 fetches/sec, 17786.9 bytes/sec
236.082 mean msecs/connect
256.73 mean msecs/first-response

WWW: http://www.acme.com/software/http_load/
