Wednesday, July 29, 2009

Remembering Mr. Erlang as a Unit

Not to be confused with Frank Zappa's daughter or a Coneheads spousal unit, is the Erlang unit. The number of Erlangs (E) is defined as:

E  =  λ S,(1)

and is a well-known in the teletraffic industry, where it was first used as a measure of call capacity. For this reason, it's also called the traffic intensity.

Tuesday, July 28, 2009

Scalability in a Spreadsheet - Google Style

Speaking of spreadsheets, it's always nice when someone, who uses your ideas, takes the time to write to you about it. Case in point, Scott Roberts sent me the following email, telling me how he'd set up my USL model in Google Docs spreadsheets.

Ignite! San Jose 2009: The Afterburn

It's been over a month since I did the Ignite event in San Jose, but I have simply had so many things to do since then, that I'm only catching up on blogging about it now.

The title of my Ignite talk was "Scalability for Quantheads: How to Do It Between Spreadsheets" (a pitch for applying my Universal Scalability Law to Web 2.0 applications using Excel spreadsheets). Since scalability is about sustainable size, I used the theme of giants as a hook. Why are there no 30 ft (10 m) giants like the one in the "Jack and the Beanstalk" fairytale? Officially, there have been no human giants taller than 10 feet (3 m); and even they need leg supports. The reasons are given in my Chap. 4 of my Guerrilla Capacity Planning book.

Friday, July 3, 2009

A Thomas Jefferson Enigma for July 4th

This post isn't about computer performance per se, although see end, and I certainly have better things to do with my time, but when I read this slashdot item about a 200 year old cipher, I couldn't help wondering what it would look like as a modern computer algorithm.