Hi Jeff,
I agree that, in many cases, the processing needs to be near the data, but
that does not rule out using a brokering layer. The broker, in fact can
be set up to run on the same network or even the same machine as the data
server. The idea is just that it communicates via web services which
means that it is easier to have some of the development take place with
different languages, compilers, even different development teams. It just
doesn't all have to be part of the same server program. That's the beauty
of using a third tier between client and server.
-- Ben
On Mon, Jun 18, 2012 at 3:06 PM, Jeff McWhirter <jeff.mcwhirter@xxxxxxxxx>wrote:
> Hi Ben,
>
>> This is a terrific idea. One suggestion I have is to build it so the
>> processing services can be set up in a brokering layer -- that is, so the
>> input datasets can be accessed via web services and the output can be
>> served via web services. I don't mean that this should be the only way to
>> implement the nco processing, rather just keep it in mind so it's
>> relatively easy to set up such a three tier architecture for the nco
>> processing.
>>
>
> I just heard from Charlie Zender and have confirmed that the NCO routines
> can operate on opendap URLs. This opens up numerous possibilities. In the
> context of ramadda one can have explicit opendap links, e.g.:
> http://ramadda.org/repository/alias/brokerexample
>
> All of the ramadda data services (cataloging, metadata ingest, subset, nco
> (soon), grid visualizations, etc) are available for that opendap link.
>
>
> 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.
>
> -Jeff
>
>
