WMSWFS and the ITD XML Gateway

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WMS/WFS and the ITD XML Gateway Saul
Farber MassGIS, EEA
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Overview

• This presentation is about a state agency making
  a system for serving maps and data to everyone
  else in the state/world.
• The main focus is on the technical integration
  with the ITD XML Gateway
• Also includes some background and motivation, as
  well as some 'success stories' of people who've
  used/will-use the finished solution

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What is MassGIS?

• Funded by the Legislature to assimilate, store
  and disseminate geographic data
• We set standards (e.g. Parcel Standard) so that
  certain kinds of data are collected correctly and
  compatibly
• We host and maintain over 300 layers of GIS data
• We act as a 'Technical GIS Advisor' to many other
  state agencies

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Background Story

• Massachusetts State GIS agency builds a statewide
  geo-data web-services framework based on
  industry-standard (but not SOAP/WSDL compliant)
  XML APIs.
• Implementation uses open-source back end
  connected to proprietary Oracle/ESRI database.

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Web-Services Technical Overview

• Our web-services stack is connected directly to
  the internet.
• Communication is via WMS, WFS and ESRI-ArcIMS
  protocols. We'll see examples later. (all are
  XML-based protocols)?

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Visual Technical Overview
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Technical Overview of our 'Standard' Client

• The other half of the GIS Shared Services
  solution was an on line map viewer OLIVER
• OLIVER is a 'reference implementation' of WMS/WFS
  client that other agencies/users could look at
  and learn from
• It also solved some data-distribution problems
  and was a very public and demonstrable success
  from the invested in this work
• Try showing the state CIO a WFS cap doc
• But it validates against the W3C XML Schema!
  You don't understand how cool that is!

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OLIVER

• Pretty much everyone loves OLIVER
• It's the public face of the project

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Unexpected Successes

• Our GIS shared services were only ever intended
  to be used by state agencies, so we only planned
  capacity to support the limited state agency
  usage
• We have so much capacity with 3 GeoServer
  machines that the shared services are now 100
  publicly available
• The great documentation and toolkits growing up
  around GeoServer and GeoTools provide us and our
  state-agency clients with a great development
  support network

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1 Best Part of GeoServerThe Community

• Every day, someone I don't know fixes a bug in
  GeoServer for MassGIS, for free
• Bug reports are publicly available, prioritized
  and are often quickly fixed
• Developers answer emails! Working with large
  corporate support staff can be frustrating
• Being a part of the conversation as well as a
  part of the team around GeoServer

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Reflections on the Experience

• Open standards from the start gave us significant
  advantages down the road
• We're on a track with lots of others
• We were able to change our problem-spots
  (server-side for us) without much change to our
  performing spots
• All our investment in WMS/WFS based viewers
  wasn't wasted when we changed our server platform
• There's not (really) an open-source ArcIMS!

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Service Statistics

• We serve many many maps.

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OGC Standards (WMS/WFS)?

• WMS stands for 'Web Map Service'
• WFS stands for 'Web Feature Service'
• Both are specification sdeveloped by the Open
  Geospatial Consortium, in a time before the real
  rise of SOAP/WSDL.
• Slightly freakish standards, try reading one some
  day.
• Try to solve some unique problems (restricting
  domain of parameters, implementability with a
  perl script, etc)?

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Sample Requests

• We keep a list on our wikihttp//lyceum.massgis.
  state.ma.us/wiki/
• WMS XML requests
• http//lyceum.massgis.state.ma.us/wiki/doku.php?id
  wmssldhome
• WFS XML requests
• http//lyceum.massgis.state.ma.us/wiki/doku.php?id
  filter_functions

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ArcIMS The ESRI Internet Map Server

• Uses a documented, but not 'standardized' command
  language ArcXML (or AXL)?
• ArcIMS does the same things as WMS and WFS, plus
  it does address to point translation or
  geocoding
• ArcIMS is expensive for us (not open source!) and
  requires licenses per processor.

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AXL Examples

• Also on our wiki
• Some AXL geocoding examples
• http//lyceum.massgis.state.ma.us/wiki/doku.php?id
  geocodinghome

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Accessing our WMS/WFS/ArcIMS from the DEP E-DMZ

• DEP (and many others!) wanted to access our
  services from their E-DMZ (or DMZ) located
  application servers.
• This requires passing through the ITD XML
  Gateway.
• We had to write schemas for AXL, but there are
  OGC-standard schemas for WMS and WFS

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DEP Application Accesses WMS/ WFS/ArcIMS through
XML-GW
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Future Possibilities

• DFW 'Baseline Survey' application
• DEP 'WIRE Project' application
• EEA 'Openspace Wiki' application
• DEP 'Watershed' application
• EOHHS 'Services Locator' application
• Many more to come!