Last week in Santa Barbara, during the ESIP Federation summer meeting, the NASA SPG hosted a Web Services technical session. I somehow got the job of lining up speakers and moderating the session, always a bit of a nail-biter. The session went well and we had some great speakers.
The presentations can be found on the SPG web site.
First up, I tried to set the stage a little bit, based on where I thought the audience was in terms of knowing about web services and REST. My biases probably showed through, but I really do think that anyone building web services that are meant to be generally accessible should not be using straight “SOA” (i.e. SOAP, WS-*, etc.) with no regard to REST. Furthermore, I think that REST wrappers around RPC-style interfaces is stopping short of where things could be.
Next, Josh Lieberman gave a presentation about OGC’s current mindset vis a vis REST. It looks to me like there is some critical thinking going on inside OGC on this topic. It remains to be seen whether there is also going to be any real motion towards specs that use REST the way it could be used. Look at some of Sean Gillies postings about APP for how OGC could benefit from REST. (Sean was, unfortunately just arriving in France and unavailable to come to UCSB).
Michael Burnett talked about ECHO. ECHO is a full-bore SOA implementation of a metadata clearinghouse for granule level NASA data. ECHO is actually testing out the REST waters a bit with some early experiments. Given when ECHO was initially designed, and the need to continue long-term, stable operation, I don’t think I can fault them for where they are today. There’s a lot to be said for keeping a stable API that can itself be wrapped in newer skins.
Switching gears a little, Jason Symonds from NOAA showed us how he’s been building a drought portal. His portal acts as a web services client to pull information from many other web sites into a single set of web pages. Along the way he’s had to develop a few web services of his own which he’s also making available via the portal.
Tyler Stevens demoed a new service offered by GCMD (his presentation is here, the portal itself is here), namely a web services discovery portal. GCMD has been a mainstay for dataset discovery for a number of years. More recently, they have been accepting submissions of web service descriptions that now can be found in the portal. What I really liked here is the way the services themselves can provide information about how to use them. For instance if you click on the WMS service link for this DataFed service entry, it brings you to a forms builder that helps you build WMS URLs.
Karl Benedict’s talk about the New Mexico Geographic Information System showed how they are developing a RESTful set of services to allow data upload and subsequent automatic generation of WxS services on that data. As the system has become easier to use, the amount of data being made available has been increasing by leaps and bounds.
The last talk came from the astronomy community, who seem to be a bit out in front of the earth observation community when it comes to a concerted effort to move to REST principles. Matthew Graham gave a great overview of what is going on in Virtual Observatories. I’m always a little surprised when I see how other communities really are not all that different from the ones I’ve been working in for years. When you get right down to it, I guess everyone has data ingestion, integration, storage, and service delivery problems, so I should not be surprised. The VO community seems to be tackling the problem with gusto and has been making good progress, from the look of it.
At the end, we had a discussion about the questions raised in the initial session description and also touched briefly on how NASA could work to maximize its benefit from being an OGC member (broadly speaking, not restricted to web services). Two whiteboard pictures (one, two) emerged, and there will be summary information posted soon, I think.
[Update: Summary meeting notes were just posted on the site. — July 16]