Hey Sheryl,

On Sep 9, 2011, at 6:10 PM, Sheryl John wrote:

> Hi,
> 
> I have questions regarding the Workflow Manager, particularly the Met File 
> writers and querying data from the File Manager.
> 
> 1) For files that are required for a PGE task workflow, do I specify the 
> metadata key-value pairs of the file ( e.g Key="TableName" Val="Chartevents" 
> ) in the metout-config.xml ?

Basically metout-config.xml is for the specific MetadataListPcsMetFileWriter 
[1] instance configured in your CAS-PGE pge-config.xml file. 
This file defines metadata to pull out of the workflow context metadata, and to 
write (and merge) with the rest of the file metadata for the product 
you are about to ingest. So, putting a key in metout-config.xml is like saying 
"I'd like to copy this workflow context metadata to the file product 
metadata".

> And, how does the Workflow mgr use the values for the next step/task in the 
> pipeline? 

See above.

> 
> 
> 2) To query the File Manager, should I use the Query building option 
> available in the PGETask Workflow Pre-Condition?
>   I have previously used the SQL-like query in a Pge Config file to pull 
> ingested files, but after reading the Workflow 2 Guide, I was wondering if 
> the File Mgr querying should be done in the pre-conditon of a task. So, this 
> would be a pre-condition for checking if input files are available before a 
> task begins. Is this right?

To use the condition based querying from PGETaskWorkflowCondition, you'd need 
to use wengine-branch. 

Rather than do so, I'd recommend just wiring the SQL(... query into your CAS 
PGE config and doing the querying there. It'll be 
simpler, and I have plans to merge in PGETask Workflow Pre-Condition later into 
the trunk for 0.4. If that's something you'd like 
to help with, I'd love to see a JIRA issue and a patch and I'll happily 
shepherd it in.

Thanks Sheryl!

Cheers,
Chris

[1] http://s.apache.org/bW4

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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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