Blogarithms
Doug Kaye's thoughts on web services, web hosting and managed services.
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Weekend Reading. Writing a new chapter, Transactions, Business Processes and Workflow, I caught up on related documents in the pile on my desk:
- Business Processes: Understanding BPEL4WS by Sanjiva Weerawarana and Francisco (Paco) Curbera, both of IBM, is a good introduction.
- Automating Business Processes and Transactions in Web Services by James Snell, also of IBM, covers the broader spectrum of transactions in general, along with WS-Coordination and WS-Transaction in addition to BPEL4WS.
- In A Novel Approach for Modeling Business Process Definitions (a 16-page .doc file) Jean-Jacques Dubray of Eigner presents the BPMI perspective on extracting process-oriented logic from applications. (You can't automate a multi-party workflow if the business logic is trapped inside the apps.) He breaks down four levels of business processes including enterprise processes, executable processes, business-process collaborations and individual tasks.
Posted Monday, September 02, 2002 2:56:57 PM 
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More on BPM and Workflow. Last week I posted a graphic portraying the latest protocol-stack developments in web-services transactions, workflow and business-process modelling and automation. As expected, I received some excellent comments from readers.
Jean-Jacques Dubray (chief architect at Eigner, author of Professional ebXML Foundations, and a co-creator of ebPML.org) writes:
I often get asked the questions: where is this whole Business Process Modeling (BPM) thing going? what is it good for? why people think it should be based on open technologies? Here is my one page answer. In one sentence I would say that the goal is that infrastructure providers such as Microsoft and IBM are working towards delivering an application model which will enable a complete separation of the process-oriented business logic from the model and presentation oriented business logic.
Dave Wright (Microsoft .NET Architecture Evangelist, who knows a lot more than that title might suggest) points out:
- BTP and WSCI both compare against WS-Transaction and WS-Coordination; that is together they compare, but separately the don’t map as cleanly.
- WS-Transaction defines 2 "transaction types", one for synchronous ACID transactions, one for "business activities." BTP compares (mostly) to the former, and WSCI (mostly) to the latter.
- In understanding the difference between a "business activity" as defined by WS-Transaction and a business process as specified in BPEL4WS, understand that BPEL4WS (and BPML) are design to specify the "internals" of a workflow, and WS-Transaction and WSCI are designed to specify the "public behavior" of workflow endpoints as they cohere in larger, cross-organizational business processes. So WS-Transaction and WSCI are all about defining the distributed eventing and notification model that is responsible for flow control as it passes across boundaries that are separately controlled by processing monitors that would be executing BPEL4WS or BPML schedules.
- WS-Coordination defines a lifecycle model for instantiating and executing distributed transactions at runtime: creating a shared transaction context, registering participants within the context and helping participants map themselves to various WS-Transaction protocols at various stages.
Posted Monday, September 02, 2002 2:04:06 PM
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Phil Windley on Warflying I didn't know that Phil was a fellow pilot and aircraft owner. I haven't posted much recently about flying or my airplane (a turbo-normalized 1976 A36 Bonanza), but you might enjoy reading about our trip last year to Mexico's Copper Canyon. Hints: stolen airplanes, banditos and boulders the size of Volkswagens.
Posted Monday, September 02, 2002 12:48:35 PM
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RDS Moves to Rackshack Like so many of my web-hosting consulting clients, my concerns over the financial and technical stability of my former web-hosting service led me to find a new vendor to host www.rds.com and a few other domains and projects. Based on Mike Prettejohn's comments about Rackshack's low-cost dedicated servers, I thought I'd give them a try. I went for their lowest-cost offer of a dedicated box with an Intel Celeron 1.3GHz CPU, 512MB RAM, 60GB hard drive, 400GB monthly transfer, RedHat Linux and Ensim Webppliance. $99/month and a $99 setup-fee. This is an entirely do-it-yourself deal. You get a ready-to-roll server, but from then on it's all yours. Rackshack will reboot the box if you kill it, but that's about it. I signed up on-line, and had access to the fully provisioned box within minutes. Not a single glitch.
It's already been an interesting experience for me. Although I've been in IT for 28 years, virtually all of that time has been spent as an executive. (The last time I had a title below VP was in 1978.) I did some major systems-level coding in the early days (writing compilers, operating systems and protocol implementations), but very little for the past ten years or so. And I've never been a sysadmin. I always had the luxury of someone else to turn to to "fix the box." Now it's all up to me.
After asking around for the best books on RedHat Linux and Apache and a quick trip to the bookstore, I went to work setting things up the way I wanted them: Perl scripts for forms, Big Brother for site monitoring, plus hardening the box and applying the latest security patches. I ran into the usual Unix/Linux problems such as getting the permissions and ownerships right and having to tweak the Apache directives--a little trickier in the virtual-host config, particularly given the Ensim Webppliance manager that thinks it's in control of everything.
I probably would have begged for help were it not for one thing: the Rackshack chat forum. Free to members, this IRC gathering is available 24x7. Even at 3am on a Sunday morning, there was someone there to answer my questions. Although the official Rackshack proposition implies very little support, I've actually found the support I've received in the chat room from Rackshack staff over the past week, superior to that for which many of my clients pay big bucks.
True, I've still got to do all the hands-on work myself--it's not a managed server--but given that I'm willing to do that (and sort of enjoying it :-)), this has turned out to be an excellent choice so far.
Posted Monday, September 02, 2002 11:05:16 AM
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