Solving the 8 Queens puzzle with bit operations

The 8 queens puzzle is a classic (and quite fun to solve) toy problem: place eight queens on a chess board in such a way that all queens could fully move without being obstructed by any other queen. While without practical applications, it illustrates a number of aspects of designing algorithms and implementing programmes: - … Continue reading Solving the 8 Queens puzzle with bit operations →

Speeding up initial page view of Ajax applications with static HTML

Many Ajax applications build the UI programmatically, i.e. think of GWT's UI builder or one of the many convenient jquery widgets which incurs a visible delay between the time of the initial page load and the time the page has finished rendering. The delay can be mitigated by a static "please wait while loading" message … Continue reading Speeding up initial page view of Ajax applications with static HTML →

The "exe" process on slow Ubuntu bootchart

Ubuntu 11.10 does already a good job at starting faster, but if you've read one of my previous posts on Ubuntu startup time [1] then you know that there is always something to be tweaked for better or for worse. Part of the process is to defer services that are not needed immediately (i.e. printing) … Continue reading The "exe" process on slow Ubuntu bootchart →

The impact of network packet loss on HTTP latency

Over the course of my involvement [1] in my Indonesian company's website, the question of how to design a website to deal with slow and bad network links presented itself over several occasions as most of our users surf either over a mobile connection or a similarly dimensioned fixed line. While optimizing design and resources … Continue reading The impact of network packet loss on HTTP latency →

HTTP pipelining, Tomcat 7 and Firefox 4

During an optimisation cycle for Bazarooma aimed at further reducing latencies I started experimenting with Firefox' HTTP pipelining [1] feature, which is disabled by default. This can be enabled by typing about:config in the URL bar, locating the network.http.pipelining entry and setting it to true. While Firebug did not report any measurable improvement, it turned … Continue reading HTTP pipelining, Tomcat 7 and Firefox 4 →