Speedy Web

With Google incorporating a “website speed” factor into site rankings, it has created renewed interests in rendering performance of web sites/apps. As a techie who has spent most of her career around web app delivery & performance, I’d like to highlight some (known) techniques and offer a few insights.

Browser-Side Optimization

Steve Souder identified 14 rules in his book for optimizing the performance of any given web page:

• Make Fewer HTTP Requests
• Use a Content Delivery Network
• Add an Expires Header
• Gzip Components
• Put Stylesheets at the Top
• Put Scripts at the Bottom
• Avoid CSS Expressions
• Make JavaScript and CSS External
• Reduce DNS Lookups
• Minify JavaScript
• Avoid Redirects
• Remove Duplicates Scripts
• Configure ETags
• Make Ajax Cacheable

These rules are primarily focused on reducing the impact of bandwidth, network latency, and the rendering of html/javascript/css.

Server-Side Optimization

As web applications become more complex and database-driven, a sluggish backend may completely negate any performance gains from client-side optimization. Back in 2003 when I managed the World Health Organization’s website, we employed a CMS tool that published all the content in static html. This allowed us to deliver a large quantity of (frequently updated) content without needing to scale out the CMS to handle millions of requests. (more…)

httpd: accelerate web page performance with mod_expires

More and more goodies are packaged with apache2, allowing one to perform front-end engineering right out of the box. Here are a tip on using mod_expires to maximize the use of browser cache and accelerate performance for repeat visitors. (more…)

Making the case for a virtualized hardware appliance

As Data Center infrastructures become more virtualized, the desire for virtualized network services increases. We see 2 types of offerings:

1. virtual appliances delivered in a VM image, such as the Netscaler VPX from Citrix
2. hardware appliances that can be virtualized, such as Cisco ACE or ASA

(more…)

Sizing Concurrent Users & Connections in a Web Environment

Calculating concurrent connections for new web applications isn’t an exact science. Fortunately Sun published a guide with an overview of the sizing process that can be applied to most web applications. (more…)

Google Tech Talk – A look at Web Security

This is a bit dated (April ‘06) but still very much relevant. This video is a tech talk delivered at Google by security expert Mike Andrews. n this TechTalk, Mike Andrews examines how web applications are attacked, walk through a testing framework for evaluating the security of an application and take some deep-dives into a few interesting and common vulnerabilities and how they can be exploited. A good primer for folks interested in Web App Firewalsl.