The Alexandria Digital Library (ADL) Gazetteer Protocol Reference Server is a web service that implements the ADL Gazetteer Protocol. It accepts a properly formatted XML document containing a query and responds with an XML report about the gazetteer entries that match the query.

The server (see Figure 1) is a layer between a gazetteer client and the database. The server has two interfaces: a Common Gateway Interface (CGI) and a Simple Object Access Protocol (SOAP) interface. Both interfaces return either an ADL standard or an extended report. The standard report is specified by the Protocol; the extended report is optional and customized for a particular gazetteer.

The CGI interface is accessible via a URL which has one parameter: the XML query. The CGI interface is accessible through all web-browsers, but the intention is to have a client built on the CGI interface which would access the server. The new ADL Gazetteer client is an example of such an interface.

The gazetteer server also accepts XML queries through a SOAP interface. The downloadable reference server code includes a SOAP wrapper for the Gazetteer Protocol, as well as an adaptation of the National Map Gazetteer Query Web Service (a SOAP interface) which was designed to access the USGS GNIS gazetteer specifically. We have adapted this interface to work with the Gazetteer Protocol and thus access various gazetteers; this adaptation is included in the code set.

You can test Gazetteer Protocol Reference Server implementations through the test forms accessible through the Gazetteer Protocol page. There are two types of test forms: the "Hands-on Introduction" provides templates for supported query types: name, name and location, type and location, etc. The "Test Forms" are designed for implementers and test the basic protocol capabilities. These forms can be pointed to a selection of servers. For local testing, these pages can be modified to point to the local test server.

The server is designed to run on different database schemas. In Figure 1, you can see that both the query translator and report builder interact with the database, so these must be reconfigured to run on a different database schema. To reconfigure the report builder, a new class that extends the Report class needs to be created.

As of August 2004, the gazetteer server code is configured to run on two different databases schemas and these can serve as models for building other report classes for different database schemas. After creating a new class, the configuration file needs to be changed to make use of the class. The query translator is configured with a python script which is in the config folder. The server is built with the ability to have two separate databases with different schemas. One for searching and one for building reports. We use this configuration in order to index the databases differently to achieve faster processing and response time.

A capabilities report is created for each gazetteer protocol implementation that specifies the functionality supported and, optionally, includes a link to a full description of the gazetteer service, the content of the gazetteer, and contact information for the responsible parties. Existing capability reports can be found by using the test forms.

The ADL Gazetteer Protocol Reference Server code can be downloaded from http://www.alexandria.ucsb.edu/downloads/gazprotocol/server/. The ADL Gazetteer client code, based on the Protocol, can be downloaded from http://www.alexandria.ucsb.edu/downloads/gazprotocol/client/.

Database schemas (both logical and physical, and including source ER/Studio files, UML diagrams, SQL create statements, and column definitions) can be viewed here, or can be downloaded as a package from schemas.tar.gz.

Please contact David Valentine, Map & Imagery Lab, Davidson Library, UC Santa Barbara, for further information.