[OSGeo-Discuss] RE: OGC WPS and Amazon SQS

[Andreas Wytzisk (52north)]

Hi Randy,
52°North (http://www.52north.org) is working on an WPS Framework Implementation. Please find details at http://52north.org/joomla//index.php?option=com_projects&task=showProject&id=21&Itemid=127

Best regards,
Andreas


> -----Original Message-----
> From: discuss-bounces at lists.osgeo.org
> [mailto:discuss-bounces at lists.osgeo.org] On Behalf Of Randy George
> Sent: Wednesday, February 27, 2008 5:12 PM
> To: Discuss at lists.osgeo.org
> Subject: [OSGeo-Discuss] RE: OGC WPS and Amazon SQS
>
> I noticed OGC finalized the WPS spec:
> http://www.opengeospatial.org/pressroom/pressreleases/843
>
>
>
> Does anyone know of projects working on WPS implementations?
>
>
>
> The goal of WPS is apparently to provide a consistent
> framework for interchangeable service process algorithms that
> can potentially be chained together into answers to higher
> level questions than the typical 'what', 'when', and 'where.'
> Dealing with 'why', 'how much', and 'what if' modeling
> usually requires a process pipeline for convolutions, boolean
> band operations, and summary pixel calculations, all of which
> are cpu cycle intense, especially for large imagery sets. In
> fact cpu usage issues would make the usual service approach
> prohibitive.  Even the little I have worked on JAI pipelines
> shows me the futility of a one cpu to many service requests
> approach for WPS.
>
>
>
> However, looking at the AWS Simple Queue Service, SQS
> http://www.amazon.com/Simple-Queue-Service-home-page/b/ref=sc_
> fe_l_2?ie=UTF8&node=13584001&no=3435361&me=A36L942TSJ2AJA,
> some interesting possibilities come to mind.
>
> Locking message queues with AMI instance pools is essentially
> a poor man's supercomputer. It would be interesting to look
> at harnessing the utility computing concept with instance
> pools available for each stage in a process pipeline
> connected using the asynchronous SQS service. This is a more
> or less controlled 'distributed computing model' applied to WPS.
>
> Ref here for some examples of existing distributed computing
> projects: http://distributedcomputing.info/projects.html
>
>
>
> Here are a couple possible approaches to a WPS service model
> that might overcome the cpu bottle neck:
>
> 1)      Sequential SQS pipeline with dedicated instance for
> each process node - this would work best for operations
> amenable to a streaming pipeline - Boolean band operations or
> pixel summary operations for instance
>
>
>
> 2)      Distributed computing model with a chunk server
> feeding a pipeline and an array pool of instances processing
> the chunks coming down the SQS queue - this would be better
> suited to tiled operations
>
>
>
> WPS is great when someone else provides the service. I
> imagine it would be very interesting to the academic
> scientific world and government groups tasked with providing
> access to all the myriad imagery coming off space sensor platforms.
>
>
>
> Just thinking out loud.   More thoughts here:
> http://www.cadmaps.com/gisblog/?p=28
>
>
>
> randy
>
>
>
>