Identity Access Management (IAM) is a very complex aspect of IT. Finding someone that really understands it is a challenge. I have found one of those guys.

Corbin Links is an expert in the implementation of various forms of access management systems - commonly called Single Sign On by those of us that need to simplify. He is the author of a trilogy of books entitled "IAM Success Tips Volume 1-3".

Corbin has gotten involved with load testing because many times his projects for large enterprises requires his team to ensure performance of IAM. We at LoadStorm are fortunate in having Corbin as a user of our load testing tool, and he has been a delightful customer. Recently, he asked if I would come on his podcast to share some thoughts about performance testing relative to IAM.

I have customers frequently ask me why LoadStorm has a minimum pause time. They want the load test to click from step to step in less than a second. My reply is that it is unrealistic to have actions of users like that.

People have to think about what they see, read it, make a decision, then click. Each person will respond to the delivered page in a slightly different time frame. Think time is variable because real users have a large deviation in their ability to process information. Some are visual learners, some are analytical, some are contemplative, some are driving personalities,

So when you are load testing, it will be beneficial to have a randomized pause between steps in your scenario. This will realistically represent the length of time from when a person receives a response (page) from your server to the time that person requests a new page.

I used to believe that interpolation for performance metrics was acceptable. However, now I have found that I was wrong. Especially when it comes to think time.

On the Software QA and Testing Resource Center site, there is a post about Estimating Test Duration. Here is a quote for your educational benefit:

CTOs Don't Get It

One of the most disruptive events at organizations is the disconnect between decisions made by managers and the views of those decisions by employees. Does this situation sound familiar?

I've have always liked Gary Busey in movies and on TV. He has starred in everything from Kung Fu to The Buddy Holly Story to the Simpsons to Gunsmoke to Saturday Night Live to Lethal Weapon. His recent appearance on Celebrity Rehab with Dr. Drew showed just how much brain damage he suffered in that motorcycle crash. In some ways, Gary's life is similar to a good stress test: Ramped up the volume until the system could not respond appropriately to requests made of it.

On to the good stuff about system performance testing.

Performance Metrics Tied to Business Metrics

Mike Kelly at SoftwareSearchQuality.com has an article about developing a working understanding of the business drivers for application performance. He postulates that a skilled performance tester can build better tests through understanding performance goals better through knowing what the business truly needs. He also believes this understanding makes test results more actionable. The key question to ask is, "What do the project stakeholders care about?" Read more about
application lifecycle performance testing and monitoring strategies.

Of course there are hundreds or thousands of posts out on the web about performance testing. I thought I would share 17 good sources focused on web application performance testing. Some of these are lists that lead to other excellent posts.

Ensuring Web Site Performance – Why, What and How to Measure Automated and Accurately

Performance Testing Articles

There was a time a few years ago that I needed to hire a Senior Performance Engineer consultant to help me set up load generation servers. I also needed help figuring out all the pieces for getting my performance testing environment setup.

As I sit here on this Monday morning and try to figure out what I should do first, it hits me that today is the beginning of an exciting year. 2009 will probably be remembered by most people as the big global economic recession. For me, 2009 will be significant because of the launch of LoadStorm.

Ricardo Sueiras is a self-professed "IT professional and geek" (found that on his blog. His formal title is J2EE Systems Architect at PricewaterhouseCoopers LLP in Canterbury, United Kingdom.

The following is an interview with David Makogon, and he shares his thoughts with us on load testing.

1. Test against your production environment.

I told this to an "expert" at the Association of Software Testing conference this year. He response was something like, "Are you kidding me?!! You'd have to be stupid to load test your production setup."

What occurred to me later in the conversation was that this guy works for a Fortune 100 company and has a six-figure annual budget (not counting his salary) just for performance engineering.

We all know how critical load testing is to a successful development effort … underestimate the possible success of your site, and you may have sabotaged that very success! If you are looking into simulated virtual user load testing for the thorough, comprehensive analysis it can offer developers, here we have some tips and tricks to make the process easier and faster.

Recognize that some questions cannot be answered

My thanks to Lawrence Nuanez for sharing his insights and testing expertise with us. In this email interview, Lawrence talks about his views on software testing, load testing, test automation, and off-shoring.

As a Senior Consultant for ProtoTest, Lawrence’s focus is mainly on load and performance testing, and he has several years of experience helping both SME and Fortune 500 clients by designing custom test plans. Use of both proprietary and open-source tools is always considered to ensure that best fit for the customer.

Dr. J Singh is a principal of Quantitecture where he helps clients improve the success rate of large software development projects. Dr. Singh has been associated with system performance for 20+ years, and was the Director of Software Development at Fidelity Investments. He managed a system performance group and created several successful new products.

Mr. Prickett, my 12th grade English teacher, was one of my all-time favorites. One day while I was arguing with him about why he took off points on my paper, this popped out of my mouth: "I assumed you knew the character because it was part of the assignment!"

He proceeded to walk to the chalk board (I'm old, before whiteboards), and he wrote "A S S U M E" in huge letters. Now he had everyone's full attention. As he explained, he circled the letters for emphasis, "for U to assume is to make an A S S out of both U and M E!

I've forgotten most of what he taught us, but I'll never forget that lesson. So I decided to not assume that people coming to our sight will know much about load testing. Hence, this post. I hope you find it useful because it isn't intended to talk down to anyone.

There is too much to say about load testing in just one blog post, so I will break this down into the key questions: what, why, who, when, how, and where. Let's start with "what".