Hi Cameron,

Looking good! Comments inline below:

On Apr 26, 2011, at 8:56 PM, Cameron Goodale wrote:

> Ok OODT List I am I think I am finally getting a formal OODT-WORKFLOW
> Education here.  But I still have some questions related to Workflow in
> general. I hope to get some understanding and to also NAIL DOWN the
> vocabulary surrounding Workflow.  I read the excellent Developer Guide here:
> http://oodt.apache.org/components/maven/workflow/development/developer.html
> but I still have some question I hope I can get clarified.

Thanks for actually checking it out rather than first declaring that you don't 
know what's going on! :) There are a lot of documentation like that on the 
website and glad you found it useful.

> 
> Vocabulary (and a sort of TRUE/FALSE, so please correct the list I am
> making)
> 
> 
> Workflow Heirarchy:
> 
>   - Event
>      - Workflow
>         - Task = java class
> 
> 
> Event
> 
>   - This is where [ALL] workflows must begin.
>   - An Event initializes 1 or more workflows
>   - IF an Event initializes more than 1 workflow the workflows will run in
>   parallel

Yep.

>   - You cannot use standard configuration to Serialize Workflows spawned
>   from a single Event

Not sure what this means? What do you mean by "Serialize"?


>   - Events DO NOT generate an INSTANCE_ID

Events don't -- Workflows that are turned into Workflow Instances do. The 
Workflow Engine is responsible for setting and returning this ID as part of 
creating a Workflow Instance from a Workflow (model).

> 
> 
> Workflow
> 
>   - Workflows DO generate an INSTANCE_ID

(Workflow Instances do -- Workflows are just models).

>   - Workflows must be used to initialize tasks
>   - Workflows are a way to logically GROUP Tasks together
>   - Workflows spawn 1 or more tasks

Yep.

> 
> Task
> 
>   - Lowest atomic level
>   - Tasks map to a single Java Class
>   - [Can tasks launch non-Java Code?]

Yep via system calls, via CAS-PGE, via the Script task, etc.

>   - [Can tasks be parallelized/serialized using config?]

Sure -- by creating a workflow with a single task. I'm not sure what serialized 
means? Are you talking about the functionality of the Workflow Instance 
repository, which (de-)serializes the Workflow Metadata, Task configuration and 
current status?


>   - [Do tasks generate an INSTANCE_ID?]

Nope, but they generate a TaskId, which is unique.

>   - [Can tasks pass input/output to each other?]

Sure, via the common Metadata context.

> 
> 
> I think that is enough questions/statements for now.  I am eager to read
> your replies.

Let me know what you think.

Cheers,
Chris

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Chris Mattmann, Ph.D.
Senior Computer Scientist
NASA Jet Propulsion Laboratory Pasadena, CA 91109 USA
Office: 171-266B, Mailstop: 171-246
Email: [email protected]
WWW:   http://sunset.usc.edu/~mattmann/
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Adjunct Assistant Professor, Computer Science Department
University of Southern California, Los Angeles, CA 90089 USA
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

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