To the casual observer, you’d think that the Service Oriented Architecture (SOA) and Grids are going in completely different directions. In fact, the two are more similar than people realize. But to make effective use of the technologies that both SOA and Grid developers and users are employing we need to change the way we think about this components, not as two disparate components, but as a single methodology that can be adapted for both sides and allow cross pollination where necessary. The intro summary reads like this:
Grids and the Service-Oriented Architecture (SOA) are two systems that appear to be on a collision course. The SOA is a standard for building discrete services, potentially across multiple machines, which can be combined to build an application that reduces integration costs. Most modern grids employ Web services like the SOA, but there is more to merging the two systems than simply employing Web services. You must also adjust the architecture of your grid solution. This article explains the concepts behind SOA and what you should consider when moving your grid applications toward an SOA model.
In Build grid applications based on SOA I take a look at the methodologies and principles that need to be adapted if we are going to use both technology groups to write and develop future, distributed, applications. Here’s some comment and analysis on the article and the convergence of SOA/Grid technology by Greg Nawrocki.
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