In a recent sprint planning meeting, solution owners unveiled how a new customer would be using our web application. Of course, it's a web application and, as such, needs to support many, concurrent users. Up until now, we were looking for our application to support approximately roughly 500 users; probably not concurrent, but potentially.
With learning how the new client will use the application, we may blow those numbers out of the water, both overall users as well as concurrent. So, how do you program and application to support large, very large volumes of users? Will the application scale if we cluster the web application servers? Will performance decrease with more users? Can we just throw a bigger machine with more CPU & memory to handle the load?
I'm a big believer in the fact that scalability needs to be designed from the get-go and then monitored. While some items may not be implemented immediately due to project constraints, scalability needs to be considered from day 1 and the code watched and reviewed to ensure new designs, code, etc will not adversely affect scalability and potentially performance.
Two articles were published in TSS on scaling JEE applications that "hit the nail on the head". If you're faced with having to support volumes of users, these articles are a must read as the writer had (has?) the opportunity to pound on application to test their ability to scale under heavy load AND to analyze why they failed or succeeded.
If you're not having to program for scalability now, the articles are still an excellent read & resource!
Scaling Your Java EE Applications - Part 1
Scaling Your Java EE Applications Part 2
