Apache jmeter is a good choice but a little more complicated. If you need something simpler for a start (as I did) go for adb (Apache benchmark) which is a comm

Apache jmeter is a good choice but a little more complicated. If you need something simpler for a start (as I did) go for adb (Apache benchmark) which is a command line tool Also, I'm not sure what are you doing but 100k simultaneous user seems like a lot, only way I can think about testing that is to get a few AWS instances and running ab or meter from them...