This article shows you how to install a gem (a ruby package) that provides access to Amazon APIs for EC2, ELB, and RDS. But along the way it also provides important information on the entire Rubygems environment. This information is critical for anyone who is tasked with maintaining a working Ruby environment.

Yesterday I posted an entry about using Ruby to access the Amazon EC2 API and I mentioned a gem that provided the classes needed to make such access easy. Gem is the package system for ruby, and fills a role similar to one that CPAN provides for perl. The Amazon gem is called amazon-ec2 and it is written and supported by Glenn Rempe.

I've been recently extolling the virtues of Ruby on the Lopsa IRC channel so I thought it would be fun to take a real world problem and write a Ruby-based solution. This particular problem has to do with manipulating snapshots in Amazon's EC2. Those who administer EC2 instances know (or should know) that the storage associated with an instance does not outlast the instance. If you want persistent storage you have to create a volume of elastic block store. Not only will it outlast the instance, it can be moved between them and it can be backed up into something called a snapshot.

On most of our instances we have a cron job that creates a snapshot of

The Call for Participation for LISA '10 has just been published. If you have not attended a LISA conference before, then this would be a great year to start. Even if you don't plan on submitting a paper or a talk proposal, reading the Call for Participation is a great way to understand how the conference works.

There is going to be a new section this year, called "Practice and Experience". It will feature 20 minute talks where people can explain a "substantial system administration project that has been completed." It should be a great way to learn from other people's successes and failures. These talks do not require full papers, but will still be reviewed and chosen by the program committee.

The single most important piece of information processed by top is the measure of a process's percentage cpu utilization, known as percent cpu. Although top is perfectly capable of display and sorting on a variety of information, by default it sorts by percent cpu. The reason for this is that most people use top to find out what the cpu is doing, or more specifically which process is hogging the cpu. Percent cpu readily reveals this information.

When someone at a conference discovered that I was the original author for the utility "top" the reaction is always the same: "hey that's a really cool program", "thanks for writing it", or "top really saved the day". I am glad that in my own little way I was able to contribute to the system administrator's toolbox. But for years I have been unable to do much additional work with top, and it has become rather out of date. I was able to keep up with some of the operating system changes, but I have not really been able to add useful features to it or to track the seemingly endless variations that others have implemented.

Now is the time to start thinking about the annual LISA conference. This year the conference will be held in Washington DC at the Wardman Park Marriott Hotel. The conference runs from December 3 through 8. I am especially proud of this year's conference. I think we have a fine collection of speakers and papers this year, and I look forward to being your host. If you want to read more about the planning and work that is going in to LISA 06, please visit the conference blog here:

http://lisa.usenix.org/blogs/lisa06/