[webservices] New ws-station revision released

Philip Crotwell crotwell at seis.sc.edu
Thu Jun 23 10:37:33 PDT 2011


I have 2 requests.

1) If the schema for a web service is going to change, please let us
know before you make the change instead of afterward. If the schema
changes, then there is a reasonable likelihood that clients will have
to be changed as well and it is much nicer if there is a little
warning given.

2) Please find a way to version the schemas you use and include that
in the XML returned from your web services. At least then a client can
tell if the schema it was coded against is different from the schema
of the returned xml. I think many places do this by putting a version
number in the URL of the schema location, so something like this could
be done for ws-station:

<StaMessage xsi:schemaLocation="http://www.data.scec.org/xml/station/1.2.3

I think it is nice to keep old version of the schema around as well.
It is not unreasonable for someone to store metadata as a stationXML
document, and without versioning of the schema, a xml file that is
"valid" one day might become invalid the next just due to schema
upgrades. It might also be a good idea to put the version of the
server somewhere, prehaps into the <Module> or <Source> elements.

As a client writer, I am very concerned about backwards incompatible
changes that will negatively effect applications that I have released.
I am happy to see ws-station and stationXML being improved, but
stability of the schema and managing the upgrade path are important as


On Tue, Jun 21, 2011 at 7:29 PM, Yazan Suleiman
<yazan at iris.washington.edu> wrote:
> Hello webservice users,
> The DMC has updated it's ws-station service: http://www.iris.edu/ws/station/
> For users parsing the StationXML returned by ws-station be aware that <NumberChannels> has been changed to <TotalNumberChannels>.  New elements have been introduced:
> TotalNumberStations
> SelectedNumberStations
> TotalNumberChannels
> SelectedNumberChannels
> We have also fixed bugs related to virtual network result sets and timewindow for channel epochs.
> For users of the DMC's Fetch scripts no change is required.
> regards,
> Web services team
> _______________________________________________
> webservices mailing list
> webservices at iris.washington.edu
> http://www.iris.washington.edu/mailman/listinfo/webservices

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