So you found an awesome new technology and it changed your life. Two weeks in and it feels like you've been taken from stone age to space age. Good for you, but better still if you can help others see the light. Thousands are still hacking away with substandard programming …
read moreMirroring an Apt Repository
When setting up a Hadoop cluster using Debian packages, it's often useful to work with a local mirror. In this article, I'll walk you through creating an apt mirror for Cloudera's Hadoop distribution.
There's quite a few advantages in having a local mirror, all of which should be familiar to …
read moreBuilding a Web-Based Java API Search
From time to time I play with web technologies to keep up with recent developments. While I know my network protocols pretty well, I'm not a frontend developer so I'm pretty useless when it comes to JavaScript or CSS. I believe in learning by doing, so I decided to build …
read moreSetting Up a Web Proxy with Squid
Setting up a Squid forward proxy can be a pretty daunting task since Squid is an extremely flexible piece of software. In this article, I'm going to provide a minimal non-caching, authenticated configuration. I have tested this with Squid 3.1.12 on Ubuntu 13.04, but with minor adjustments …
read moreInstalling Ubuntu 13.04 on my Dell Precision M65
A few days ago I bought a larger and faster disk for my Dell Precision M65 notebook. If it wasn't for the new disk, I would have never tried the latest Ubuntu (13.04, aka "Raring Ringtail"), because 12.04 worked fine for me. Feature-wise I haven't noticed a lot …
read moreQuick Tip #5: Navigating in Source Trees
I often move around in checked out Subversion or Git source trees on a Bash command line. Directory structures tend to get quite deep (especially in Java projects), so one problem keeps coming up frequently: Changing back to the base directory of the source tree. Typing "cd .." ten times is …
read moreGetting Started With Kerberos
Recently, I have been playing with Kerberos, a popular Single Sign On system (SSO) that is used in many large organizations. My first contact with Kerberos has been at university in a network security course, but that only covered the cryptographic part, not the more practical issues like setting up …
read moreUndoing Things With Git
Bourne Shell Parameter Expansion
Classic Bourne Shell has a handy feature that many people don't seem to know: Parameter Expansion. Stephen Bourne describes it in An Introduction to the UNIX Shell, which is part of the original Unix V7 manuals from 1978. Among other things, parameter expansion provides a notation for making sure that …
read moreMatplotlib: Plotting Bar Diagrams
A while ago we plotted time series data with Matplotlib. This worked nicely, but with the data at hand, a bar diagram would have looked much better. In this article I'll give you a template for using bar diagrams with time series data. This builds on the work we did …
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