Thursday, October 29th, 2009

In December, I'll give a talk at SAPO Codebits 2009 in Lisbon, Portual. SAPO Codebits is a hacking event held in Portugal annually, completely organized and sponsored by SAPO, a portuguese ISP and subsidiary company of the Portugal Telecom Group. I will be speaking about web server architectures, web services in general and discuss the […]

Thursday, October 29th, 2009

Since the Apache load balancer seems to be my topic of the week, let's focus on another related question: What happens if a worker (backend server) doesn't show up for work? Let's say server B needed to go down for maintenance and is no longer available for the cluster: For this example I simply shut […]

Wednesday, October 28th, 2009

HTTP load balancers have one natural enemy: redirections. For example, a "trailing slash" redirect is issued when the server receives a request for a URL http://servername/dir where dir is a directory. In such a case the server redirects the browser to http://servername/dirname/ (including the trailing slash): # lynx -mime_header http://loadbalancer/dir | egrep Location: Location: http://serverA/dir/ […]

Tuesday, October 27th, 2009

Usually a single AMP system is enough to serve - let's say - around 500 concurrent users. Sometimes more, sometimes less, strongly depending on the particular web application, the overall architecture of your system, of course the hardware itself, and how you define "concurrent users". Nevertheless, if your server gets too slow, you'll need to […]

Monday, October 26th, 2009

Sun Microsystem's employee blogging site (affectionately named BSC) uses Apache Roller to manage the site and house all the blogs. Roller is an open source Java blog software that for example also drives the US Government's and the IBM Developer Works blogs. But there is one feature I really missed: An entry counter […]

Thursday, October 22nd, 2009

Yesterday, I started a small tutorial on how to implement typographic headlines with PHP. There were some aspects to be aware of, but in general it was an easy and straight forward process. The final result looked like this: But there was one big issue I had with my script: It was far to slow […]

Wednesday, October 21st, 2009

My recent blog post about scaling images with PHP gave me the idea to write something about creating typographic headlines with PHP. At Apache Friends we're using this technique since many years to get rid of the usual boring and everywhere available "web fonts" like Helvetica, Times and Verdana. For this example I chose the […]

Tuesday, October 20th, 2009

Scaling images in PHP is quite easy, but there are some things to consider. (If you're short of time, right at the end you'll find the final script.) Read the original image with imagecreatefromjpeg() First of all you'll need to read the original image. If it's a JPEG file the imagecreatefromjpeg() function is the right […]

Wednesday, October 14th, 2009

Today I want to show you a quick installation walkthrough of Sun GlassFish Web Stack. I'm using Solaris 10 in this walkthrough, but installation on RHEL is absolutely the same. As a small deployment example for a web application I'll do an installation of WordPress. Web Stack Installation Okay, first step: Get the Sun GlassFish […]

Tuesday, October 13th, 2009

Just learned that the question "what is java" is on place 3 of Google's Zeitgeist ranking 2008 for "what is" questions - right after "what is love" (first place) and "what is life" (second place). Indeed a good question. Let's take a look a Google's top hits to this question: (Hit #9) Java is […]

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