Load Test Calculating Number of Virtual Users

Question

I have an application which must achieve 5 Requests per Second on a load Runner Load Test, did someone know how many Virtual User do I need in 1 Hour? Thank you so much in advance for your reply

Answer 1

Seems pretty simple. Have five virtual users request the same image every second with no caching. And there you have five requests per second.

More likely than not the person who wrote that requirement is a server manager and not the business owner for the application. The number of requests for an application can change dramatically based upon server and CDN configuration as well as the size of the audience accessing the site.

If this is an update to an existing application then you are well advised to seek a copy of the HTTP request logs. Examine the average/90th percentile session duration, which is measured as the time between the first and last timestamp for a given IP address. Next, count the number of distinct IP addresses present in your block of average or percentile based session duration. This will provide an objective view of the number of users online.

Now that you know the number of users go back and count the number of page level requests made within a particular block which represents your high water period. What you will find is that you will have distinct pages which represent business processes. For instance, you may have a page called "order_confirmation.htm" which will tell you how many orders were completed during the window. Likewise you may have another page called "about_me.htm" which indicates the number of people viewing their profile, and so forth.

Make your test objective, tied directly to objective data. Five requests per second could be easily shaped by a simple change to the cache management on the server or CDN, so this represents very little to do with a business process.