My first Cassandra contribution

A bit surprisingly and somehow accidentally, today I became a Cassandra contributor. I had a problem with the project I do for work, which made us unable to make our bulkloading script work together with Cassandra authentication (which I described in one of the previous articles on this blog), so we decided to try solving this issue on our own.

The solution was quite simple, but gave me a bit more of Cassandra knowledge and understanding. If you are interested in contributing to Cassandra I think you can take a look at this problem and the solution or even try to reproduce this problem (on Cassandra 1.1.0-rc1 or earlier) and then try to solve it on your own. As I said it was simple, so you won’t get frustrated with the problems you will face, but I think it’s good start for something more. Here is the link to Cassandra’s bug tracker issue:

https://issues.apache.org/jira/browse/CASSANDRA-4155

Working on interesting things, being nicely paid for this and contributing to remarkable Open Source projects in the same time – could it be any better? ;)

Adding simple authentication to Cassandra

Today I was asked to set up user authentication in Cassandra, so we could stop using the “default” user with unrestricted access only. I have to say that I was really surprised when I noticed that there’s NO out-of-the-box authentication and authorization framework in it. Luckily, it can be easily enabled in a few steps which I’m going to show you.

One important thing – SimpleAuthenticator we’re going to use is in the “examples” directory of Cassandra package. It’s because it is considered to be very simple and not very safe (it was even called a “toy” in one of Cassandra’s Jira tasks), so DO NOT rely on it as on a serious protection tool for your system. However it still fits many requirements (i.e. you don’t want user to make a mess in a Column Family he doesn’t need to work on) so you may find it useful. You have been warned.

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Mounting HDFS cluster as a block device with hadoop-fuse

Using Hadoop may quickly become very annoying if you have to navigate through the HDFS filesystem with a standard hadoop command. As a Linux user I got used to TAB-autocompletion feature, which lets me quickly and easily use my filesystem so I was really disappointed with this difficulty. Luckily – there’s a solution which eased my pain!

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Extending Xubuntu desktop to external display using xrandr

Few weeks ago I’ve bought a new laptop and I’ve installed a new Xubuntu 11.10 on it. Surprisingly (and sadly), when I tried to connect an external display to it, I found out that it’s impossible to do it in “out of the box” version of Xubuntu. I had only a choice to use my external display instead of the internal one or to do a “mirror” configuration, having the same on both displays… Satisfying? No, thanks. I had to find out how to do it in the way I want it to work.

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