I want to test my web site for 20000 users. Has anybody used Web Application Tool to generate such a large number of users and load test a web site.
How many client machines will be required?
Re: 200000 users
1. Do you need 20000 users in any given second? or over a period of time like a day?
2. How much $$ are you willing to spend...?
20,000 users is a huge site... Yahoo like or ETrade etc...
Re: 200000 users
Milind, I posted a reply to this question in "Performance & Load Testing" under the topic you entered of "200000 user."
As I stated there, you run into the large issue of overtaxing your testing client machines such that you introduce bottleneck and congestion artifacts into your results.
It would help to know what you are testing for specifically. Do you want to see how your infrastructure scales? Are you looking to see transaction performance of a given sort under load? Are you trying to determine the point at which average load on a given server reaches a saturation point?
As AJ says, this is a lot of users you are considering and it would be handy to know how you derived that number (was it from server logs?) and to what ratio you are going to be testing them. Are they going to be staged concurrently or are you looking at simultaneous users? I assume you mean unique users in a given time period which is a much different situation. In any event, your answer to that will determine how much you need for your client machines. If you are talking 20,000 simultaneous or concurrent users you are talking about having a lot of hardware available but I highly doubt your site is getting hit with 20,000 simultaneous connections. There are not too many sites I know of that get hit like this and not too much hardware that can handle it well.
The answer to your question is that, yes, you can simulate 20,000 users. But what time ratio are you looking at? Are you considering 20,000 users per day? In that case, take your 20,000 and divide that by the number of seconds in a day. This will give you how many users have to start per second. (In this case, you would have less than one user starting per second.) But know that there is no limit, theoretically, to what the Web Application Stress Tool can handle - just as much as your processors and memory will be able to handle.