Tuesday, 22 July 2008

Best Practices Alleged; Your Mileage May Vary

Yahoo! quite often releases interesting/useful/thought-provoking tools for people doing "serious" Web development. I add the modifier to specify that we're usually not talking about the Joe Leet three-page magnum oopus; a lot of what they do and talk about really only pays huge returns when you work with a site as large and complex as, well, Yahoo!.

Recently, they brought out a couple of nifty tools that integrate into the Firefox browser's Firebug Web-developer-Swiss-Army-knife extension. One of these, YSlow ("why [my site] slow?") does some interesting evaluations and calculations against whatever page (with secondary requests) you throw it at. Its "Performance" tab shows how your page matches up against Yahoo!'s new "Best Practices for Speeding Up Your Web Site." At first blush, a lot of these make perfect sense; "Avoid Redirects", "No 404s", and so on. YSlow, on the other hand, evaluates against a slightly different set of guidelines to those on the Best Practices Page:

1. Make fewer HTTP requests
2. Use a CDN
3. Add an Expires header
4. Gzip components
5. Put CSS at the top
6. Put JS at the bottom
7. Avoid CSS expressions
8. Make JS and CSS external
9. Reduce DNS lookups
10. Minify JS
11. Avoid redirects
12. Remove duplicate scripts
13. Configure ETags

"Huh?", our hypothetical Web pseudogod Mr Leet might well ask. "What the heck is an 'ETag'? Or a 'CDN'? Does any of this even apply to me?" Well, Joe, yes and no. For instance, content-delivery networks like Akamai or ATDN, as you might well know by hearing the names, scatter servers at strategic places around the planet with the aim of reducing the time it takes to get data from huge, media-content-heavy sites like CNN.com or the like, down to your browser at the end of a surprisingly long chain. Does everybody who puts a site up need something like this? Does the average small-to-midsize business? Usually not, unless you really are a Web Hype-Dot-Oh site that shoves exabytes out every day to wow the yokels or the investors. For the local pizza joint with a site containing maybe forty files, tops, with a couple of megabytes of images, a CDN is thermonuclear overkill. As many Web-development sites have pointed out for the last decade, there's quite a bit you can do to speed things up and lower bandwidth usage without spending the big bucks on this.

Why do I blather on about this when I started talking about best practices and YSlow? Because for practices to be "best", they first and foremost have to be appropriate for the use at hand. Buying a Lamborghini Countach to go down to the corner store for some sodas will quite likely get you yelled at by the Significant Other (followed by your bank). But if Lewis Hamilton showed up at pole position in a '72 Ford Pinto... you'd hear the laughter from St Paul to São Paolo.

Use the tools and techniques appropriate to the task at hand. There's a lot that small Website developers can learn from Google and the tools they publish. Getting an "A" score has a certain karmic appeal, and most of the optimizations required are straightforward anyway (tweaking how your Web server serves your data, for the most part). But is this worth all the geek love it's been getting?

Until someone with the developer credibility and experience of a Yahoo! stands up and explains a better set of practices for the SMB developer, the answer seems to be "yeah, probably". We who make our living (or our diversion) from the creation, care and feeding of Web sites are, for the most part, artisans posing as engineers, with inconsistent knowledge or practice of our craft; we dream of building the online equivalent of the Empire State Building but wind up with the Cologne Cathedral; a wonder, yes, but surely 600 years was well beyond the original estimated schedule! Agreed-upon standards (so that, say, a page appears identical in different browsers),; a shared, common body of knowledge; even (gasp!) widespread, vendor-neutral certifications of professional competence will eventually become common in software (including Web) development for the same reasons as, say, in architecture. The artifacts involved (skyscrapers, Web sites) have important social and policy implications, and inconsistent competence in practice poses a real and serious danger to the public at large. Sooner or later, it's going to be uneconomic for the present ad hoc system to advance the state of the art, or to meet the needs placed upon its products.

Best practices are good; best practices that actually work for the stated purposes in a broad variety of praxis are much better. But to get there, we're going to need to collaborate and communicate effectively, and to do that, we're going to have to make sure everybody involved is speaking the same language to describe the same things. If we don't, we'll continue to be stuck in pretty much the same place we are now — with a bunch of shade-tree mechanics running around in the pits at the Monaco Grand Prix...only doing a lot more damage.

Comments are welcomed, as always.

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