MCslp

Comparing traditional grids with high-performance computing

Traditionally, high performance computing was carried out by specialized hardware and software working together to produce a highly optimized environment. Grids are beginning to change that, by removing the need for the specialized elements while enabling the spreading of the work across a wider range of hardware, software, and networks. A new article takes a closer look at the two solutions, and how they are converging.

From the article introduction:

Parallel computing is a methodology for designing applications designed to work within large parallel computing environments. In a grid system, the execution of an operation or equation is geared toward providing a structure for executing tasks in parallel, where the order in which the work units are executed and received is not sequential and not reliant on previous code iterations. While, overall, the models of these two systems — parallel computing and grids — are converging, the traditional programming models of these two systems remain different. In this article, we will look at parallel computing, grids, and their convergence.

Read Comparing traditional grids with high-performance computing.

System Administrators Toolkit: Monitoring disk space and usage

The next article in the System Administrators Toolkit series, this time on monitoring disk space and disk usage by users, is available at IBM developerWorks.

This one focuses on finding out your disk storage, where it is being used, finding out who is using it, and, when necessary, controlling the usage through the quota system.

From the developerWorks preview:

Look at methods for determining disk usage across multiple UNIX systems and how to create a simple warning system to alert you of potential problems. Keeping an eye on your file systems and ensuring they don’t fill up is a trivial, but vital process in the day-to-day management of your UNIX systems. In this article, you’ll look at methods for keeping an eye on disk space, discovering which files, users, or applications are using up the most space, and how to make use of quotas and other solutions to find the information you need.

Read System Administrators Toolkit: Monitoring disk space and usage.

Perl/Eclipse tutorials picked for top 27

My Building Perl Applications and Debugging Perl Applications with Eclipse tutorials have been picked in a list of the top 27 Eclipse tutorials.

You can see the full list here.

System Administrators Toolkit: Monitoring a slow system

When your Unix/Linux system starts going slowly, you need to find out why, and quickly, what is going on. That’s the focus of my new SAT piece: Monitoring a slow system.

From the intro:

When your UNIX system runs slow, it is vital that you discover what the problem is as quickly as possible so you can get your system back into the normal operating mode. There are many causes for a slow system, but actually identifying the problem can be exceedingly difficult. In this article, study examples of how to identify and diagnose the cause of your slow running UNIX system to get your machine running properly again.

Read the full article.

MediaWiki Review

The latest in my reviews of hosting provider open source software is available at Free Software Magazine.

You can read the full review here.

Wikipedia is a Wiki - basically a information storage engine that works entirely through a web interface. I describe it more succinctly in the article:

A Wiki - of which MediaWiki is one of the most widely used and best known - provides a simple, web-based environment that enables users to collaborate and provide and share information. Wikis are not about discussions, and they are not about regular articles or posts, like a blog.

I have a number of installations, including one that I use to record and document the internal systems here. A companion blog documents changes. There’ll be more about that over on MCslp Coalface soon.

LoCA 2006 Photos

I’ve managed to find some photos of me presenting my keynote at LoCA 2006.

You can view the full set of all photos here. I’m the guy in white.

The somewhat jaded faces are nothing to do with my presentation, but the late night and then early morning start that the group had had the night before!

Writing text parsers with yacc and lex

Lex and yacc are two tools that you may be aware of, but have maybe never used. They are key components to compilers, configuration tools and many different languages, where the ability to parse text and generate some other output (assembly code, or simply to understand the contents). To explain how the system works, I have a new tutorial at IBM developerWorks.

Entitle Writing text parsers with yac and lex, the tutorial primarily focuses on how the two tools work. To demonstrate the significance of precedence (order of execution) and structure, I use calculators as the main example, before moving on to how to parse and understand text.

You can read the article through this link, but you may also want to use the additional examples that I placed onto MCslp Coalface.

There are two follow-up articles:

• Building an RPN to Equation Parser
• Building an Equation to RPN Parser

These demonstrate how you can modify the output generated by, for example, an RPN parser so that it outputs normal equations, and vice versa. There’s an example in the tutorial the covers shows how you can link these two together.

LoCA 2006 Keynote

As previously announced, I presented the keynote at LoCA 2006.

The keynote was on Google Maps and Google Earth, related to the new book which I just announced on the book’s new companion website.

I’d like to think that the presentation went well - we started late (due to Dublin traffic, the attendees had trouble getting in - my taxi, by comparison, got us there an hour early), but we finished even later as the questions and queries came thick and fast. We had a taxi booked at 11:00am to take us to the airport, but by 11:15am my wife had to come and collect me to ensure we made it for the flight.

If any LoCA attendees want to comment, please feel free!

As to the book - and apologies to those from LoCA who I instructed to visit this site for more information - I’m just in the process of organizing the examples and downloadable book content today.