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

[Raj Singh]

I just attended an Open Grid Forum event (http://www.ogf.org/OGF22/)  
where lat-lon and 52north showed off some very nice WPS work. OGC  
plans to work more closely with the Grid community to further improve  
our service offerings for distributed computing, but it won't be a  
quick and easy process. There's a lot of work to be done in this area.

---
Raj


On Feb 27, 2008, at 9:04 PM, Dr. Markus Lupp wrote:

> Hi Randy,
>
> deegree has a WPS implementation (although by now it supports only  
> WPS v. 0.4.0). We plan to publish an easy-to-install WPS Demo  
> Release for deegree 2.2, coming in June (1st Release Candidate in  
> April).
>
>
> Regards,
>
> Markus
>
>
>
> Randy George schrieb:
>>
>> 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 
>>  <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
>>
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>
>
> -- 
> Dr. Markus Lupp
> l a t / l o n  GmbH
> Kupang-NTT
> Indonesia
> phone +62 (0)81 339 431666
> http://www.lat-lon.de
> http://www.deegree.org
> --
>
>
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