[webservices] Beta release of ws-station, including a new StationXML schema

[Chad Trabant]

Hi,

Explaining our strategy and the situation a bit further.  We have worked for a while to get to the point where we do not expect StationXML to change in a non-backwards compatible way, with this next change we intend to stick with the current version of the schema for a long while.

It is our intent to maintain a stable service interface.  Highest on the list is to avoid changing things that break current client usage, we have client software too so we suffer along with the community on that one.  Also, not all clients are broken by this update (changes to the XML are relatively small).  Another factor is the merit of the update, the previous results did not include critical information such as the type of the Poles and Zeros in the response cascade (how was anyone using those without knowing if they were expressed in radians/sec versus Hertz??).  Less directly import for the users, there is the consideration of how much infrastructure the data center should run to support older versions for indefinite periods, we run a growing suite of services, each one has redundant instances on redundant hosts on redundant hardware.  Putting all these factors in a reasonable balance we decided not to split off a new service interface, even though this will break some client usage.

On the horizon, the FDSN versions of these services are being planned.  These are already being designed to include a specification number in the URL, the intention is to be able to make future updates and maintain older versions in parallel.

Chad

On Mar 9, 2012, at 6:08 AM, Philip Crotwell wrote:

> Hi
> 
> Echoing John and going one step further, I wish you would consider
> adopting a less disruptive server upgrade policy that brings new
> versions of the web services online in parallel with the existing ones
> when there are "breaking changes". It is really unfair, IMHO, to
> expect users to all be using version X clients on April 1 and to all
> switch to version Y on April 2. This is a problem for your users,
> especially as these web services become more popular.
> Users just do not upgrade software that rapidly and I think the DMC,
> once it "releases" a service from beta mode to production, has an
> obligation to support the client software that is coded to that
> version for some reasonable period of time. Otherwise you are saying
> that there MUST be a new release of Emerald, SOD, and every other ws
> client program on April 2nd. New versions won't work on April 1st and
> the old version won't work on April 2nd.
> 
> This could be easily accomplished if the version of the web service
> was part of the URL.
> 
> I too do not wish to stand in the way of progress, but it is hard for
> me to justify putting time and effort into building a web services
> client if I can't count on my software working tomorrow.
> 
> Philip
> 
> On Thu, Mar 8, 2012 at 9:05 PM, John D. West <john.d.west at asu.edu> wrote:
>> Hi.
>> 
>> I don't like to be the one to slow down progress, but I have oral exams on
>> April 2 and have no time before them to test the beta or update EMERALD to
>> handle the new schema. Is there any chance we can put this one off for a
>> week or two?
>> 
>> Many thanks,
>> 
>>      -- John
>> 
>> 
>> On Wed, Mar 7, 2012 at 6:04 PM, Yazan Suleiman <yazan at iris.washington.edu>
>> wrote:
>>> 
>>> Hello webservice users,
>>> 
>>> The DMC has released a beta version of our ws-station service and would
>>> appreciate any level of feedback.  The changes in this release include an
>>> update to the StationXML schema making the results NOT backwards compatible
>>> with the current service (more details below).  Also introduced are new time
>>> range selection parameters.
>>> 
>>> http://www.iris.edu/wsbeta/station/
>>> 
>>> We anticipate this version replacing the current service on April 2nd.
>>>  After which any clients depending on the (few) changes in the schema will
>>> not work correctly.  In particular, the beta Java IRIS-WS Library (and the
>>> related MATLAB support) will stop working properly.  We plan on releasing
>>> new versions of the IRIS-WS Library at the same time to match this update in
>>> the ws-station service.
>>> 
>>> regards,
>>> Web services team
>>> 
>>> 
>>> Details of the changes include:
>>> 
>>> 1) New starttime and endtime parameters, the timewindow parameter is now
>>> deprecated as these two parameters provide the same and much more
>>> functionality.  In addition to allowing start and end times to be specified
>>> independently these new parameters allow time to be specified (as opposed to
>>> only a date).  See the service help for details.
>>> 
>>> 2) The service has been updated to the latest StationXML schema:
>>> http://www.data.scec.org/xml/station/20120307/station.xsd
>>> 
>>> The relavent changes for ws-station users are as follows:
>>> 
>>> A) The SEED "site name" is now placed in the <Name> element inside the
>>> <Site> tag.
>>> before:
>>> <Site>
>>>  <Country>Ankober, Ethiopia (near Debra Birhan)</Country>
>>> </Site>
>>> 
>>> after:
>>> <Site>
>>>  <Name>Ankober, Ethiopia (near Debra Birhan)</Name>
>>> </Site>
>>> 
>>> This rearrangement also removes the <Name> element previously found inside
>>> of a the Channel <Epoch> tag.
>>> 
>>> B) Removed the swap_order attributes from the Station <Epoch> tag
>>> <StationEpoch> instead of <StationEpoch swap_order_16="BIG_ENDIAN"
>>> swap_order_32="BIG_ENDIAN">
>>> 
>>> C) Removed stage 0 response structure, this is replaced by the 'Channel'
>>> 'InstrumentSensitivity structure'.
>>> 
>>> D) Added new elements describing <PolesZeros> and <Coefficients>:
>>> <PzTransferFunctionType> and <CfTransferFunctionType>
>>> 
>>> E) Replaced <GainUnits> with <SensitivityUnits> inside of
>>> <StageSensitivity> tag of a response cascade.
>>> 
>>> _______________________________________________
>>> webservices mailing list
>>> webservices at iris.washington.edu
>>> http://www.iris.washington.edu/mailman/listinfo/webservices
>>> 
>> 
>> 
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>> 
> 
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