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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