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 These days, I mostly post my tech musings on Linkedin.  https://www.linkedin.com/in/seanmcgrath/

Wednesday, September 15, 2004

Firefox and Thunderbird - get them. No questions. Just do it.

The Firefox/Thunderbird Browser/E-mail client combination is wonderful, keenly priced [:-)] and getting better with every release.
Just get them. Okay?

Monday, September 13, 2004

Python/XML talent required

Propylon are looking for Python/XML programmers. Opportunities in both Dublin and Sligo offices. Contact me if interested.

Friday, September 10, 2004

Pushing and pulling in XML message exchange

Whenever two systems need to "talk", the nature of the speech acts to be used raises its head.

Do I talk while you listen?
Do I ask you a question and you answer me?
Do I state a fact and broadcast it to anybody who happens to be listening?
Do I sit back and say "go on, ask me a question"?

Some of these choices can be safely relegated to implementation detail. i.e. technically speaking, numerous options can be made to work.

However, some are directly impacted by the boundaries - both physical and organisational - between the communicating parties.

In the Public Services Broker - an SOA based integration infrastructure under construction in Ireland, many of the services connected to the PSB will be hosted by agencies separated from the PSB both physically and organisationally.

As a consequence, it is necessary to analyse the various possible meessage exchange choreographies and take these "business" issues into account. The document Push and Pull Message Delivery in the PSB Architecture is a position paper on the topic.

Although the document is specific to the PSB, the questions discused have a wider applicability in any SOA based on an asynchronous messaging substrate.

Comments welcome.

Tuesday, September 07, 2004

I guess. Its a problem.


    All guesses have bigger guesses, on their backs to bite them.
    And smaller guesses within those guesses, and so on, ad infinitum.


With apologies to Augustus de Morgan and all the world's fleas.

Guesswork features in a lot of software. We like it. We want it. It makes software smart. Or does it? Deleterious guesswork in application integration is an ITWorld article that ponders the pros and cons of the guessing game we call data processing.

Saturday, September 04, 2004

What is a 'brittle' interface?

Brittle interfaces are bad right? But do you and I mean the same thing by the word 'brittle'?. Read what is a brittle interface? to find out.

Monday, August 30, 2004

A mountable filesystem from your GMail account

Create a 1 GIG mountable filesystem from your GMail account. Sometimes you just gotta smile.

Sunday, August 29, 2004

WS-Ectomy

Gregor talks a whole bunch of sense about WS-Yikes. The last para resonates strongly with my own approach:

    """Therefore, I propose to many of my clients to use the WS-* standards as a checklist for their designs. I generally do not recommend they use WS-Addressing or WS-ReliableMessaging (or at least not right out of the gate). I do, however, challenge them by asking, "What is your strategy to track messages in case of error?" or "How do you intend to support asynchronous messaging?" The answer has sometimes little to do with Web Services. For example, the answer to reliable asynchronous messaging might be to use JMS or MQ or another middleware that ensures guaranteed delivery of asynchronous messages. And that's OK. ..."""

It is truly amazing how much you can do just with URIs (applied RESTfully) and an underlying off-the-shelf, boring-as-the-day-is-long reliable asynchronous messaging substrate.

If you have better things to be doing than tracking WS-Palimpsest and struggling to debug WS-InterferencePatterns, I suggest you get an asynch messaging substrate in place, off the shelf *now* and work forward from there.