There seems to be a lot of stress/load testing tool that support AJAX.
I am wondering how well does these tool implemented.
Do they only record http request and repl
Check out Jiffy. It's an end-to-end measurement suite, and is subsequently kind of complex. However, the statistics are quite impressive.
All load testers would support AJAX- they're just additional http connections.
There are a few free ones out there- Jmeter, BadBoy, Grinder that all do it well.
All of them have some sort of support for recording/playback, but that's not always what you're looking for.
Easiest way I've done it is to record a sample session, replace a few params with variables and loop it off of a csv or excel file.
Great starting point: video of a google presentation on open source testing.
Edit: updated video link.