my thoughts

I have been reading up on capacity planning and load testing for IIS based web applications, I found the following resources which I think useful to share. My recent training in ITIL IT SMF has provided a useful and standard vocabulary to the techniques that I have practised over the years as a web developer. The following resources can be filed under Capacity Management, one of the five components in the ITIL Service Delivery model.
» Service Management Functions high level overview: Capacity Management
» Introduction to Capacity Management: summary and implementation plan
» IIS 6 web server scalability resources on Microsoft TechNet
» Case Study: Scaling an ASP.NET web application on IIS 6 — Illustrates how to monitor and tune IIS 6.0 for improved performance and scalability

Performance optimization and capacity planning for Microsoft Content Management Server
I am responsible for two large MCMS websites. The first section of this report shows how to achieve optimal performance from an MCMS site by making use of caching, and by analyzing, scaling, and tuning the site to eliminate any site bottlenecks. The second section covers capacity planning—how to plan for, estimate, and manage the maximum anticipated load capacity for your site.
» www.microsoft.com/technet/prodtechnol/cms/plan/cmsoptim.mspx

This is a work in progress, more resources soon...

The domains of web accessibility and web usability often overlap, given the need to communicate effectively with the widest appropriate audience. In march 2006 the Disability Rights Commission produced a document called PAS-78, which provides accessibility guidance for people who commission websites.

The document provides information in a fairly non-technical manner and covers how disabled people use the web, defining an accessibility policy, technology (CSS, scripting, plugins), accessibility testing and maintenance, and contracting web design and accessibility testing services. It also covers the W3C guidelines, and provides advice on involving disabled people in the development phase.

I recommend obtaining a copy of the report, and gaining a working knowledge of the recommendations if you are actively involved in web accessibility and usability. The document is now free to download from the DRC.

Download the PAS-78:
» www.drc.org.uk/library/website_accessibility_guidance/pas_78.aspx

An overview of the report:
» www.accessibility101.org.uk/pas78.htm
» www.bsi-global.com/ICT/PAS78/index.xalter

With IE7 now in Beta2, and due for release in the latter part of this year, now is an excellent time to test existing web applications with it. One of the more exciting features for web developers is the improved CSS support, and better widgets (the SELECT element is now windowless, for example, so can be given a z-index). I will post more resources and information on this in the near future.

IE6 continues to be important. Given the current best practise of 'develop in Firefox, patch in IE', the following IE6 resources make for interesting reading:
» Rounded Corners in Internet Explorer: Staying Ahead of the Curve (March 2005)
» An overview of "HasLayout", explanation, demonstrations and workarounds (August 2005)
» Internet Explorer Developer Center on MSDN
» I found these on the IE blog


How to attack an Internet Explorer display bug
The widely-used "holly hack" provides a common workaround for the various dimensional bugs presented by MSIE. The following page provides a particularly good explanation of the technique, together with clear:left; position:relative and the "tan-hack":
» How To Attack An Internet Explorer (Win) Display Bug


More detail on the hasLayout property within MSIE.
Why do you care? When working with CSS & html to implement a design according to current recommendations* it is guaranteed that you will encounter weird bugs in Internet Explorer... most commonly "Why has that box disappeared?" or "What's it doing over there?!". To quote from the article:

"The hasLayout problem affects designers (and coders) at all experience levels. Layout has unusual and hard to predict effects on the display of boxes, as well as implications for their descendant elements. Consequences of an element having, or not having “layout” can include:

* Many common IE float bugs.
* Boxes themselves treating basic properties differently.
* Margin collapsing between a container and its descendants.
* Various problems with the construction of lists.
* Differences in the positioning of background images.
* Differences between browsers when using scripting.

The above list is brief and incomplete. This article attempts to more thoroughly describe issues encountered by the application of “layout” or the lack of it."

The article is long but well written, and I recommend giving it a read so that next time you encounter "weirdness" you will have a useful starting point for debugging the CSS.
» www.satzansatz.de/cssd/onhavinglayout.html

* the box model of CSS positioning, semantic order

I read another interesting post at Jeff Atwood's CodingHorror.com where he uses a power meter to work out how much power his laptop, desktop, server and various household appliances use. The answer is, quite a lot! His 'the cost of leaving your PC on' page has some practical advice on how to be more energy conscious with your PC.

Michael Bluejay's Saving Electricity site has a useful How much electricity do computers use? page, together with a wider series on energy consumption.

I presently work at an organisation where it is the policy that workstations are left on permanently (apparently owing to shortcomings in their software update distribution service). I disagree with this policy as it is a tremendous waste of energy. There are thousands of computers throughout the organisation, magnifying the problem. I expect to collect more evidence here, as part of building a business case to have the policy changed.

The short answer is yes, they use a lot of power, yes you should switch off the pc (or at least put it in standby) and turn off the monitor rather than use a screensaver. The actions of one person make a difference!

As a web developer I am often consulted regarding search engine optimisation (SEO) and where to advertise online. It is useful to keep an eye on what is happening in the search world. I am sure that most web developers will be able to tell you that Google is the leading search engine these days, and that Yahoo, MSN, Ask and AOL make up the other majority. The small remainder is comprised of the legacy search providers.

The following summary report is provided by netapplications, showing the relative search popularity. There are no surprises in the report.
» marketshare.hitslink.com/report.aspx?qprid=1

Statistics are only relevant when you know the context in which they are collected and what they represent. The homepage offers an introduction to their data collection methods and sample size:
» marketshare.hitslink.com/ (scroll down for 'About Our Market Share Statistics')

The relative market shares are displayed monthly on the search engine share trend page.
» marketshare.hitslink.com/report.aspx?qprid=4

The Search Engine Watch website is a useful starting point in understanding the current state of the search world
» searchenginewatch.com/

Jeff Atwood maintains a coder's blog which covers .net development and human factors (two things I spend a lot of time with). I recently picked up on his summary of 13 attributes of considerate software. These are simple factors that set a software application apart from the crowd by putting the user's needs before its own.

These principles are easily applied. For example, I prefer to be flexible with date input fields. Rather than forcing the user to enter a specific date format (dd/mm/yyyy) and throw back some validation if 'bad' data is supplied, I work with the user, allowing flexible date entry in any format and gracefully parsing the supplied information into a valid format.
» www.codinghorror.com/blog/archives/000550.html

I found out about the Symphony for Dot Matrix Printers ages ago, but the subject recently came up in conversation. I recommend you give this a listen!
» www.theuser.org/dotmatrix/en/intro.html

The Silophone gives industrial scale interactivity from a microphone and speaker placed inside a disused silo. You upload a sound sample, which is then played, recorded and sent back to you. The reverb on this thing is wild!
» www.silophone.net/

I recommend that you check out these amazing works from this talented new artist!
» www.apictureofbritain.com/Antonia-Winsor_ogallery.html

Further to my notes on making an accessible website I thought I should provide some resources for online testing & validation tools for Web Content Accessibility Guidelines (WCAG 1.0) and Section 508. The following resources provide automated accessibility testing to varying degrees of quality.

WebXACT from Watchfire (formerly Bobby) is a free online service that lets you test single pages of web content for quality, accessibility, and privacy issues. Provides a detailed and useful report.
» webxact.watchfire.com/

HERA is a tool to check the accessibility of Web pages accoridng to the specification of WCAG1.0. Very easy to use, providing excellent visual results which highlight areas of your page and/or code that need attention.
» www.sidar.org/hera/

WAVE: "Web Accessibility Versatile Evaluator" web accessibility tool. This tool is very useful as it returns the page marked up with icons or 'tags', showing pros and cons in sematic order. These tags provide a good insight into how the page will be interpreted by a non-visual user-agent so are very good for content order (semantic markup) testing.
» wave.webaim.org/

Cynthia Says: A web content accessibility validation solution, it is designed to identify errors in your content related to Section 508 standards and/or the WCAG guidelines - Single page evaulation only and includes user-agent impersonation to masquerade as common browsers. Results presented in a simple table of checkpoints.
» www.contentquality.com/

The following tools provide more basic reporting functions:
» www.ocawa.com/Test-your-Web-Site_6_en/
» checker.atrc.utoronto.ca/
» www.ubaccess.com/artguide.html

It is good to hear that the Fairtrade movement is gathering momentum. An article published in today's Guardian asks how Fair is Fairtrade?. The answer — very fair! Even the economists love it. Read on...
» www.guardian.co.uk/g2/story/0,,1725816,00.html (pda version)