Webinar: Load Testing Meets Data Analytics

This Thursday, October 27 at 10 am PDT^*, I'll be participating in a webinar sponsored by SOASTA, Inc. They make a new breed of load-testing product called CloudTest® which, despite its name, is not restricted to load testing cloud-based apps, although it can do that too.

Kanban Revived in an Agile Kind of Way

I just returned from a workshop on the latest in web technologies (invitation only) where I was surprised to hear reference made to kanban. Kanban is a card-based system originally developed by Toyota in the 1950s for controlling their manufacturing lines. I have a note about it in the "Brief History of Buffers" section of my Perl::PDQ book because it is a logical precursor to JIT scheduling and compiling. I will also discuss it in the up-coming Guerrilla classes.

Now, it seems kanban has been revived under the "agile" banner for making software development more efficient. Of course, the concept of using cards to capture dev state information is not entirely new, even in the context of software engineering. So-called Snow Cards are another card-based technique used to monitor the software development process.

Visual Illusions: Google vs Facebook vs Yahoo

The ability to visualize data, enabled by the advent of graphical computer tools, has been a great boon to Cap and Perf. The power derives from the way graphical displays provide an efficient impedance match to the visual system in our brain. The weakness derives from the way graphical displays provide an efficient impedance match to the visual system in our brain. We can get carried away by visual representations alone. Every marketing organization exploits that weakness. Numbers do have poor cognitive impedance, but that doesn't mean numbers should ignored altogether. In fact, we often need a combination of both numerical and visual data representations so that we don't suffer visual miscues and thus jump to the wrong conclusion. The following presents an example of how easily this can happen.

Recently, Guerrilla alumnus, Scott J. pointed me at this Chart of the Day showing how Google revenue growth was outpacing both Facebook and Yahoo, when compared 7 years after launching the respective companies.

Clearly, this chart is intended to be an attention getter for the Silicon Alley Insider website but, it looks about right and normally I might have just accepted the claim without giving it anymore thought. The notion that Google growth is dominating, is also consistent with a lot of other things one sees. No surprises there.

Plan for GCaP in November

Seats are still available for the final Guerrilla Boot Camp (GBoot) and Guerrilla Capacity Planning (GCaP) classes for 2011 at the Early Bird rate. Before registering, you can review the highlights of the May GCaP class. If you came to the August GDAT class, but missed the May classes, this is your chance to complete the set.




As usual, it will be held at our lovely Larkspur Landing location. Click on the image for booking information.

Attendees should bring their laptops, as course materials are provided on CD or flash drive. The venue also offers free wi-fi to the internet.

How Much Wayback for CaP?

How much data do you need to retain for meaningful capacity planning and performance analysis purposes? Sounds like one of those "how long is a piece of string?" questions and I've never really thought about it in any formal way, but it occurred to me that 5 years is not an unreasonable archival period.

Mister Peabody and Sherman in front of the WABAC machine
My reasoning goes like this:

Subjugation to the Sigmas

No doubt you've heard about the tyranny of the 9s in reference to computer system availability. You're probably also familiar with the phrase six sigma, either in the context of manufacturing process quality control or the improvement of business processes. As we discovered in the recent Guerrilla Data Analysis Techniques class, the two concepts are related.

Nines	Percent	Downtime/Year	σ Level
4	99.99%	52.596 minutes	4σ
5	99.999%	5.2596 minutes	-
6	99.9999%	31.5576 seconds	5σ
7	99.99999%	3.15576 seconds	-
8	99.999999%	315.6 milliseconds	6σ

In this way, people like to talk about achieving "5 nines" availability or a "six sigma" quality level. These phrases are often bandied about without appreciating:

IBM Introduces the Cognitive Chip

Last week, in the GDAT class, we were discussing performance visualization tools as requiring a good impedance match between the digital computer under analysis and the cognitive computer of the analyst—AKA the brain.