Joseph D Sloan, High Performance Linux Clusters

Getting the best performance today relies on deploying high performance clusters, rather than single unit supercomputers. But building clusters can be expensive, but using Linux can be both a cheaper alternative and make it easy to develop and deploy software across the cluster. I interview Joseph D Sloan, author of High Performance Linux Clusters about what makes a cluster, how Linux cluster competes with Grid and proprietary solutions and how he got into clustering technology in the first place.

Clustering with Linux is a current hot topic – can you tell me a bit about how you got into the technology?In graduate school in the 1980s I did a lot of computer intensive modeling. I can recall one simulation that required 8 days of CPU time on what was then a state-of-the art ($50K) workstation. So I’ve had a longtime interest in computer performance. In the early 1990s I shifted over to networking as my primary interest. Along the way I set up a networking laboratory. One day a student came in and asked about putting together a cluster. At that point I already had everything I needed. So I began building clusters.

Improved application development: Part 1, Collating requirements for an application

My latest Rational piece is up on the IBM site. This is an update of the series I co-wrote last year on using a suite of Rational tools for your development projects. The latest series focuses on the new Rational Application Developer and Rational Software Modelere, which are based on the new Eclipse 3.0 platform.

Developing applications using the IBM Rational Unified Process is a lot easier if you have the tools to help you throughout the process. The Rational family of software offers a range of tools that on their own provide excellent support for each phase of the development process. But you can also use the different tools together to build an entire application. By sharing the information, you can track components in the application from their original requirement specification through testing and release. This first part of a five-part series shows how to use Rational RequisitePro to manage and organize the requirements specification for a new project. Then, after you’ve developed your unified list of requirements, the tutorial shows how to use Rational Software Modeler to model your application based on those requirements.

You can read the full article. If you’ve finished it and want more, check out Improved application development: Part 2, Developing solutions with Rational Application Developer.

Using HTTP Compression

I have a new article up at ServerWatch which looks at the benefits and configuration of HTTP compression within Apache and IIS. Here’s an excerpt from the intro:

There’s a finite amount of bandwidth on most Internet connections, and anything administrators can do to speed up the process is worthwhile. One way to do this is via HTTP compression, a capability built into both browsers and servers that can dramatically improve site performance by reducing the amount of time required to transfer data between the server and the client. The principles are nothing new — the data is simply compressed. What is unique is that compression is done on the fly, straight from the server to the client, and often without users knowing.HTTP compression is easy to enable and requires no client-side configuration to obtain benefits, making it a very easy way to get extra performance. This article discusses how it works, its advantages, and how to configure Apache and IIS to compress data on the fly.

Read on for the full article.

Interview with Tom Jackiewicz, author of Deploying OpenLDAP

My first article for LinuxPlanet is an interview with the author of Deploying OpenLDAP, Tom Jackiewicz. The book is an excellent guide to using and abusing the OpenLDAP platform. As well as the contents of the book, I talked with Tom about the uses and best environments for LDAP solutions, as well as technical requirements for OpenLDAP. We also have a little discussion about the complexities of the LDAP system. You can read the full interview.

Tom Jackiewicz, Deploying OpenLDAP

OpenLDAP is the directory server of choice if you want a completely free and open source solution to the directory server problem. Tom Jackiewicz is the author of Deploying OpenLDAP, a title that aims to dissolve many of the myths and cover the mechnanics of using OpenLDAP in your organization. I talked to him about his book, his job (managing OpenLDAP servers) and what he does when he isn’t working on an LDAP problem.

Could you summarize the main benefits of LDAP as a directory solution?There are many solutions to every problem. Some solutions are obviously better than others and they are widely used for that reason. LDAP was just one solution for a directory implementation. Some people insist that Sony’s BetaMax was a better solution than VHS–unfortunately for them, it just didn’t catch on. The main benefit of using LDAP as a directory solution is the same reason people use VHS now. There might be something better out there but people haven’t heard of it, therefore it gets no support and defeats the idea of having a centralized directory solution in place. Bigger and better things out there might exist but if they stand alone and don’t play well with others, they just don’t fit into the overall goals of your environment.If you deploy any of the LDAP implementations that exist today, you instantly have applications that can tie into your directory with ease. Because of this reason, what used to be a large scale integration project becomes something that can actually be accomplished. I’m way into standards. I guess LDAP was simple enough for everyone to implement and just caught on. If LDAP existed in the same form it does today but another directory solution was more accepted, maybe I’d be making arguments against using LDAP.Please read the rest of the interview at LinuxPlanet.

Finding alternatives in developing software

My latest article over at Free Software Magazine is available. This time, I’m looking at the role of free software in development, both of free and proprietary applications. I discuss the benefits of free software and the pitfalls of proprietary solutions. Here’s an extract of the intro:

Developing software within the free software model can be achieved with all sorts of different tools, but choosing the right tools can make a big difference to the success of your project. Even if you are developing a proprietary solution, there are benefits to using free software tools to achieve it. But what free software tools are available? In this article I’m going to look at the development tools available, from languages and libraries to development environments, as well as examining the issues surrounding the use of free software tools by comparison to their proprietary equivalents.

You can read the full article.

Patrick Koetter, Ralf Hildebrandt, The Book of Postfix

Postfix is fast becoming a popular alternative to sendmail. Although it can be complex to configure, it’s easier to use Postfix with additional filtering applications, for example Spam and virus filters, than with some other mail transfer agents. I spoke to Patrick Koetter and Ralk Hildebrandt about The Book of Postfix, the complexities of configuring Postfix, Spam, and email security.

How does Postfix compare to sendmail and qmail?Ralf Hildebrandt (RH): As opposed to sendmail, Postfix was built with security in mind.As opposed to qmail, Postfix was built for real-life systems in mind that have to adapt to the hardships of the Internet today. qmail is effectively unmaintained.Patrick Koetter (PK): That’s a tough question because I am not one of those postmasters who spent half their life working with Eric Allman’s Sendmail nor did I spent too much time enlarging my knowledge on qmail, so I can’t give you an in detail answer that will really tackle specific features or functionalities.Let me give it a different spin and try if that answers it:

Cristian Darie, Mihai Bucica; Beginning PHP 5 and Mysql E-Commerce

PHP and MySQL are common solutions in many web development situations. However, when using them for e-commerce sites some different techniques should be employed to get the best out of the platforms. I talked to Cristian Darie and Mihai Bucica about their new book which uses an interesting approach to demonstrating the required techniques; the book builds an entire T-Shirt ordering shop.

Could you give me, in a nut shell, the main focus of the book?When writing “Beginning PHP 5 and MySQL E-Commerce”, we had two big goals of equal importance in mind. The first goal was to teach the reader how to approach the development of a data-driven web application with PHP and MySQL. We met this goal by taking a case-study approach, and we did our best to mix new theory and practice of incremental complexity in each chapter.

Garrett Rooney, Practical Subversion

Subversion is having what can only be described as a subversive effect on the versioning software environment. CVS has long been the standard amongst programmers, but it has it’s faults and Subversion (read Sub-version) addresses those known and perceived about CVS. I talked to Garrett Rooney about his book Practical Subversion, his contributions to the Subversion code and where Subversion fits into the scheme of your administration and development environments.

I see from the book you are a strong believer in version control – can you summarize the main benefits of version control?I like to think of version control as a way of communicating information between developers.When you commit a change to a source tree you can think of it as an automated way of telling every other developer how they can fix the same problem in their source tree. The benefits go further though, since in addition to keeping everyone on the team up to date with the latest fixes, you’re also recording all of the history. This means that later on, when you want to figure out how a piece of code got the way it is you can look at the series of changes (and hopefully the justification for the changes, if you’ve been good about writing log messages) that let to the current situation. Looking at that history is often the best way to understand why the code got the way it is, which means you’re less likely to make the same mistake twice when making new changes.

Computerworld Blogs

Computerworld have set up a dedicated blogging area on their site at Computerworld blogsThere are a few of us there; all dedicated to blogging on different news stories in a range of different areas and topics. You can read my blog at the dedicated Martin MC Brown Computerworld blog. Alternatively, you can subscribe to my dedicated RSS feed. You can see that we’ve been populated it over the last week or so; there are already blog posts from me, and others, about a variety of topics. Please feel free to read and either comment there, or here and let me know how I’m getting on.