Re: [thredds] nco as a web service

But for a useful service, the form and syntax of the URL should be independent 
of the mechanism that does the server side calculations  (which rules out 
SWAMP).  So for example, both Grads an F-TDS use the same format in the URL to 
say that "this is an expression", but the expressions themselves are platform 
specific.  That is not the way to get overarching services.

Instead, we need agreement on how in the URL request we signal a server-side 
function, the syntax of that function (independent of the engine underneath) 
and a few simple functions to start  (say simple data transformations, 
differencing and averaging on a dimension(s)).  Then the server back-end can 
parse the request and use Ferret or Grads or NCO or Python or whatever is 
desired, and like with any good service, the back end could change  without 
having any affect on the URL or the user.

I know Matthew Arrott at least used to like the approach in Chapter 12 of 
"Python Scripting for Computation Science".  But a lot of that is the engine 
underneath.  I am more interested in the form of the URL.  Get some agreement 
on that, and some real implementation could proceed.

-Roy





On Jun 18, 2012, at 2:37 PM, Russ Rew wrote:

> Jeff,
> 
>> However, we have to keep in mind performance ramifications. It still takes
>> a long time to move gigabytes of data across a network. This brings up the
>> importance of moving the computation to the data, instead of moving the
>> data to the computation. For some data sets and many use cases remote
>> access to data works very well so things like brokering are tractable.
>> However, for *big* data sets (e.g., climate model output) we need to come
>> up with richer mechanisms (like the NCO on local data) to bring computation
>> to the data.
> 
> See Daniel Wang's SWAMP (the Script Workflow Analysis for
> MultiProcessing), built on top of NCO:
> 
>  https://code.google.com/p/swamp/
> 
> --Russ
> 
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NOAA/NMFS
Environmental Research Division
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