The Web Services Reliable Messaging (WSRM) standard is an extension of the web service model to allow secure communication of information between web services clients and servers. By secure, I don’t mean in terms of security or encryption, but instead in terms of the reliability of sending and receiving the messages. sing a combination of sequencing, retransmission and two-way acknowledgement, WSRM is a much needed alternative in a grid environment for exchanging vital information.

Here’s the intro extract from a new tutorial on understanding the basics of WSRM and its implementation at IBM developerWorks:

Discover how the Web Services Reliable Messaging (WSRM) standard defines an environment, sequence, and structure for sending and receiving reliable messages. The goal is for a WSRM-enabled system to transmit messages, even in the event of a network, platform, or simple application failure. In this tutorial, you’ll look at the WSRM specification, the basic mechanics of getting the system running, and an example of how the system works.

You’ll be looking at the WSRM standard, why you need it, how you can use it, and how the WSRM standard provides reliable message exchange. In particular, you’ll look at the following topics:

• Reliable Messaging need
• Reliable Messaging Model
• Sequence example
• Reliable Messaging protocol
• Reporting faults
• Using WSRM for grid communication

You can read the full tutorial.

I interview Arnold Robbins, maintainer of Gawk and author of Linux Programming by Example: The Fundamentals about his book, Gawk and how maintainers like me are kept in check.

Here’s an extract:

LP: Do you think there’s a need for such low-level programming guides?

Robbins: Yes, I do. It’s wonderful to program at a higher level of abstraction, such as what Java and Python give you, or in a different way, what the shell gives you.

But there are times when you’ve got to get as close to the metal as you can, and that calls for C or C++ and direct system calls. Besides, I think it’s kind of neat to see the clear relationship between the way the Unix system calls work and the semantics made available at the shell level (I/O redirection, piping), and that in fact it’s not really such difficult dark magic after all.

Read the full article

The Web Services Distributed Management (WSDM) standard offers a way for you to publicize and manage machines and web services using web services and associated technologies. If you’re confused by that statement then you probably need to read my new tutorial, Understand Web Services Distributed Management (WSDM).

Here’s the abstract:

Management through Web services simplifies the numerous interfaces and solutions that provide management tools for network-attached systems and devices. These range from simple printers to more complex operating system management issues. The Web Services Distributed Management (WSDM) standard defines two different environments, Management Using Web Services (MUWS) and Management of Web Services (MOWS), that define the structure and environment required to support these systems. This tutorial looks in detail at the definition and implementation issues of WSDM and how you can use WSDM within grid environments for the management of grids and grid services.

Read on for the full Understand Web Services Distributed Management (WSDM) tutorial.

The fifth and final piece to the Improved Application Development series is now available. This one looks at testing your application before the next phase of development or release. Here’s the abstract:

Testing is a vital part of any development process, and to perform adequate testing you need not only to identify faults but also to trace and track these faults, fixes, and the components they affect during each iteration of the development process. In this tutorial, you’ll learn about the integration between the IBM Rational software testing products and other tools used in the development process, such as IBM Rational RequisitePro, IBM Rational Application Developer for WebSphere Software, and IBM Rational ClearQuest.

The full article is on the IBM DeveloperWorks site.

Again, for a recap, you’ll want to read the rest of the series in sequence before you get to this one:

1. Improved application development: Part 1, Collating requirements for an application
2. Improved application development: Part 2, Developing solutions with Rational Application Developer
3. Improved application development, Part 3: Incorporating changes in requirement
4. Improved application developerment: Part 4, Part 4: Building a Web client

Part 4 of the Improved Application Development series, which covers a development from end-to-end using Rational tools is now available.

Written by Nate Schutta, it concentrates on extending the application to work on the web, using the powerful features of the Rational environment to make the developed as quick and easy as possible.

Here’s the intro blurb:

In this tutorial, you’ll return to the Auction application that you developed in Part 2. You’ll add functionality to what you developed previously and connect to your entity beans via a Web-based front end. You’ll take advantage of leading-edge technologies like JavaServer Faces (JSF) and Extensible Hypertext Markup Language (XHTML) to create a dynamic Web project — and, thanks to IBM Rational Application Developer’s powerful Web design features, you’ll hardly have to touch the keyboard.

Click on for the full tutorial.

The story so far:

1. Improved application development: Part 1, Collating requirements for an application
2. Improved application development: Part 2, Developing solutions with Rational Application Developer
3. Improved application development, Part 3: Incorporating changes in requirement

The next article in the Improve application development series is now up at the IBM site.

This follows on from Part 2, written by Nate Schutta, and moves on to managing the project now that the application is being developed and the you start getting faults and change requests into the system that need to be tracked and monitored. The main focus here then is the Rational ClearQuest system and it integrates with the other tools you’ll use in the process, including the original RequisitePro and the new Rational Application Developer and Rational Software Modeler tools.

Remember, these later tools are based on the Eclipse platform and that means that the interfacing code is written as a plug-in to the Eclipse environment.

Here’s the intro description:

The focus of this third tutorial in the “Improved application development” series is on change management. This tutorial shows how individual change requests are linked and traced back to the original requirements specification, how you manage that information from within your development environment, and how you generate a new specification.

You can read the full tutorial.

As a recap, this tutorial follows on from:

Improved application development: Part 1, Collating requirements for an application
and
Improved application development: Part 2, Developing solutions with Rational Application Developer

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.

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.

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.