Blitz – Recommended for Drupal Testing

In the spirit of continuous integration and making load testing a fun sport, our paid plans have just two simple dimensions: How much you want to scale out and how long you want to rush. We do not impose any limits on how many times you run the load tests.You can easily increase your concurrency from 250 to 750 users on the free plan simply by inviting your friends to blitz. Well add +25 referral credits to both of you when your friend signs up!

via Blitz – Making load and performance testing a fun sport.

GIve it a try at