LoadStorm

Andrew Lombardi is a Java Software Engineer and Head Geek of Mystic Coders, LLC in Santa Ana, California. His blog provides insight into many aspects of technology.

Our thanks to Andrew for taking the time to share some information with us.

I'm reading the classic book The Art of Software Testing by Glenford Myers. While it may be old (copyright 1979), it is still full of golden nuggets. Myers uses real examples from the ancient days of software development to demonstrate the practical side of testing.

One of my favorites is his definition of stress testing.

"Stress testing is the process of evaluating failure points in a web application by introducing adverse conditions into the runtime environment."

A web developer called me the other day and asked, "Is load testing the same as performance testing?"

I pondered for a moment and replied, "Not really." Hmmmm...now I needed to support my answer. Thus began a hunt for good answers to my client's question.

Searching Google, gleaning from our interviews, and asking respected colleagues were parts of my pursuit for the truth about load vs. perf. Sorry to abbreviate, but I've heard cool engineers shorten it to "perf", and I desperately want to be cool. (in a geeky way)

In the spirit of New Year's resolutions, I'm going to try to provide as many tips of the week as I can. There are weeks when I might get too busy, but I'll sincerely try to post a small hint or trick that will be helpful to web developers. Tips may be about load testing, performance testing, performance tuning, stress testing, or anything related to web application development.

Performance Reference Point

Your website is a little slow - so what? Well, it is probably costing you money. I have been researching published facts about web performance because we are always trying to understand our industry better. This post should help you realize that improving your web application performance can directly impact your bottom line by 10% or more. Don't believe me? Read on...

What is the Slashdot Effect?

The Slashdot effect occurs when a smaller website is flooded with visitors, usually as a result of being linked to from a high profile website. The name comes from the Linux and Open Source blog http://slashdot.org, a site which handles 80 million page views a month. Many home servers or low bandwidth sites that post content interesting to one of these larger blogs have experienced significant downtime when the traffic from Slashdot suddenly migrates to their own servers. Performance engineering for the Slashdot effect is essentially engineering for a worst case scenario - but that worst-case involves more traffic than developers could ever have imagined!

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.

Many CIOs do not embrace cloud computing. They have pressures from stakeholders to make system service levels "five nines", and clouds don't offer those SLAs. The trade-off is between highly redundant and available systems at a high cost to maintain compared to much lower cost without the guarantee of high availability. Cloud server platforms are relatively very inexpensive, but it isn't perfect.

Ok, this comes under the heading of "weird stuff" and it is a stretch to call it load testing. My thinking is that this guy is running a test to see how many Madagascar hissing cockroaches fit into his mouth. I don't think it is stress testing because he isn't trying to exceed the capacity of his mouth. In stress testing, he would be trying to break the system; however, in this instance of the test, he is merely trying to break a record (11) previously set by a guy in Kentucky.

Today we're looking at some server overload circumstances from the sad, to the silly and the very expensive ... and some where the hackers got the blame for something that may well have been the load tester's responsibility!

Website flooded after heavy rains

Anyone know how I can find some cool things that happened in information technology on this day in history? I tried to Google it, but the results are useless. However, I did find out that today is Blog Action Day, which is an annual event held every October 15 that unites the world’s bloggers in posting about the same issue on the same day with the aim of sparking discussion around an issue of global importance.

Today is the 67th birthday of a musician who has been relevant in the mainstream for longer than virtually anyone else in modern music. Paul Simon was big when I was a child and still has a strong following. I remember the tunes of Simon and Garfunkel playing in our house before I even knew any of the entertainers. "I am just a poor boy..." was more than just a song, it was my story.

Performance testing is important. Web developers never want their sites or applications to crash under load. If they do, so what? Not all of the failures below are related to high traffic, but the failures are notable because of their impact on users and the far-reaching ripple effect.

From promising thousands of customers £7 top-of-the-line computers, to nearly causing an 800-plane pile-up, 'inconvenience' doesn't even begin to describe some of the most famous application failures.

A Little Cache Goes a Long Way

Drupal is the target of load testing for this series of articles. If this is your first time reading any of the articles in this series, please review the introduction and summary called Load Testing Drupal for a good context of what we are doing.

Everybody has problems. As web developers, we are trained to find solutions using technology. I submit to you that the most important things (all great lists come in threes) when solving a web problem are:

1. Simpler is better
2. There is always a way
3. Passion overcomes intelligence and skill

Simpler is Better