Apache Benchmarking
Be careful, these can cripple a server as they might mimic a DOS attack.
Benchmark Tool: weighttp
weighttp -n 100000 -c 100 -t 4 -k "http://127.0.0.1:8080/100.html"
Benchmark Tool: httpperf
httpperf --hog --server=example.com --num-conns=1000 --rate=20 --timeout=5
Benchmark Tool: ab
ab -n 100000 -c 100 -t 1 -k "http://127.0.0.1:8080/100.html"