Collected thoughts about software and site performance ...

Web performance matters. Responsive sites can make the online experience effective, even enjoyable. A slow site can be unusable. This site is about online performance, how to achieve and maintain it, its impact on user experience, and ultimately on site effectiveness.

Home | Entries about Slowness (4), in reverse date order:

jQuery Library Performance Alert

Illustration: jQuery logo

Recently I've been doing a lot Web design and development work, using the Squarespace platform, a "A fully hosted, completely managed environment for creating and maintaining a website, blog or portfolio." I like Squarespace because it is xhtml/CSS based and lets me focus on a site's content and appearance. I get great performance and never have to deal with installing and managing any Web server software. Normally ...

Click to read more ...

Where Performance Meets Availability

Illustration: Stopwatch

Earlier posts about Acceptable Response Times have discussed how a Web site or application's responsiveness can Delight, Satisfy, or Frustrate customers.

Availability, on the other hand, is a measure of a system's stability. It is not a performance metric, it is a software (or hardware) quality metric.

So, technically speaking, performance and availability are orthogonal issues. Practically speaking, however, availability and responsiveness are interconnected concepts.

Click to read more ...

Latency, Bandwidth, and Station Wagons

Illustration: Station Wagon

One concept that continues to elude many IT managers is the impact of latency on network design. 11 years ago, Stuart Cheshire wrote a detailed analysis of the difference between bandwidth and latency in ISP links [It's the Latency Stupid]. Over a decade later, his writings are still relevant. Latency, not bandwidth, is often the key to network speed, or lack thereof.

That's from It's Still The Latency, Stupid by William (Bill) Dougherty, writing in edgeblog on May 31, 2007. Bill follows that opening paragraph with a very readable explanation of the vital importance of latency (round-trip time) as a factor affecting performance in TCP networking. He uses what he calls the Sandbag Problem to illustrate his points:

Click to read more ...

Shopping in Slow Motion

Illustration: Holiday shopping crowds

Slow Motion Shopping?

I'm always on the lookout for interesting news about performance, so there isn't much that surprises me. But occasionally performance can mean something rather different from what I have in mind.

Last August, Ben Rushlo wrote about his recent experiences measuring some Online Retail sites, and the performance issues he uncovered. As summer approaches once more, most retailers are busy building and testing their 2007 holiday shopping sites.

Thinking about this, I was searching for articles about slow shopping performance. Among them I found this news item, which comes complete with video coverage. Slowness, it turns out, can be more fun that I ever imagined.

Click to read more ...