Hey ThomasB (we have 2 “TomB”s now, so I’ll fully use your
name ;) )

Great questions. My thoughts below:



-----Original Message-----
From: Thomas Bennett <[email protected]>
Reply-To: "[email protected]" <[email protected]>
Date: Wednesday, April 22, 2015 at 6:09 AM
To: OODT <[email protected]>
Subject: Datastore references for a duplicate products

>Hi,
>
>Okay - so a 'flat' product has a single datastore reference.
>
>So, how do you handle redundant copies of products? At the moment I have
>an
>independent catalogue at each site.
>
>I was thinking of a site metadata key, so multiple products can be
>filtered, but I thought I would see what other people are doing and if
>there is any interest in perhaps getting a product (flat or heirachical)
>with multiple references, i.e. beyond originalReference and
>datastoreReference.

My personal opinion is that tagging each Product with a “Site” metadata
field would be a great idea and a great way to filter this later.

>
>Or does that totally break the OODT model? It probably does...

Nope doesn’t break the model at all - the Product with structure
ProductStructure.HIERARCHICAL works fine with this - data transfers
work fine - metadata retrieval works fine (try ingesting a directory),
and other things work fine too.

However, I would seriously advise *against* using this model ^_^
Mostly b/c no one really does it that way - and the code isn’t actively
being developed and maintained. At one point I thought it would be a
great thing to support and the last I heard of someone using this structure
natively was OCO from 2007/2008 (a NASA mission).

>
>Also - does anyone store data on tape library and index it with OODT. I'm
>talking basic tar on a tape. This obviously breaks the file retrieval, if
>used, but I'm thinking of how this could be included in the OODT framework
>and maybe develop some methods.

Well yep we do this - one way to do would be to add a
TapeBasedDataTransferer,
and/or utilities to handle waiting for data e.g., from Tape. You could also
use the InPlaceDataTransferer, and then come up with a Versioner that
easily
supports having Tape-based URIs.

Does that make sense?

Cheers,
Chris

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Chris Mattmann, Ph.D.
Chief Architect
Instrument Software and Science Data Systems Section (398)
NASA Jet Propulsion Laboratory Pasadena, CA 91109 USA
Office: 168-519, Mailstop: 168-527
Email: [email protected]
WWW:  http://sunset.usc.edu/~mattmann/
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Adjunct Associate Professor, Computer Science Department
University of Southern California, Los Angeles, CA 90089 USA
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++


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