Achieving maximum HTTP requests per second with Webserver Stress Tool

In order to generate a maximum number of HTTP requests per second you should look at the following tips:

• Webstress heavily relies on multithreading. Using a system with multiple processors and/or multicore CPUs helps a lot.
• Memory should not be any issue with 1 GB RAM or more
• Remove network bottlenecks: Use a fast network (Gigabit or more), fast switches etc.
• Connect the machine running Webstress to the same switch as the server to be tested
• Run a TIME based test (CLICKS based may also be ok)
• Use a few hundred users (e.g. running with 200-500 users has shown good results). Running with 1000 users or more may decrease performance due to increasing thread synchronization overhead, because each "user" is simulated by its own thread
• Set Click Delay to 0 seconds (this causes Webstress to send the next request immediately after the previous one has finished)
• Use simple URL sequences (complex URL scripts can waste a lot of CPU power)
• Disable HTML parsing (i.e. disable download of images, frames, objects etc.)
• Disable saving of HTM files to the disk and disable the link checker
• If you can live without it: disabling Detailed Logging and Request Log also pushes performance
• Do not use a proxy (proxies should never be used with Webstress)

Finally, if all this does not give you enough testing power you may want to consider multiple systems running Webstress concurrently. The disadvantage is that you will not get aggregated test results though.