DEF System Architecture XML Web Services Fedora and the Zebra Search Engine in an OAI Eprints...
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Transcript of DEF System Architecture XML Web Services Fedora and the Zebra Search Engine in an OAI Eprints...
DEF System ArchitectureXML Web Services
Fedora and the Zebra Search Engine in an OAI Eprints Application
by Gert Schmeltz Pedersen, [email protected] - +45 4525 7244
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Contents
1. XML Web Services and the 3-tier Architecture2. The DEF Eprints Service3. DEF-XWS Eprints4. Generic Search Service5. Repository Federation
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DEF-XWS project suite
"XML Web Services and the 3-tier architecture"
a project suite within the programme area System Architecture at Denmark's Electronic Research Library (DEFF) (http://defxws.cvt.dk)
a collaboration with The Royal Library, The State and University Library, Aarhus Business School Library a.o.
Get web services hands-on and experience.
Get Fedora hands-on and experience.
Use Fedora to implement a web service version of
DEF Eprints - International eprints metadata harvested from Open Archives, a DEF project carried out at DTV.
Add full text indexing and retrieval.
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Data base
Data base
Data base
Data base
Data base
Data base
Data base
Data base
Data base
Data base
Data base
Data base
Data base
Data base
Data base
Data base
Common service
Local Portal
Common service
Common service
Local service Local service Common service
Central Portal
Webbrowser
DEff 3-tier Service Oriented Architecture
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The DEF Eprints ServiceArchitecture of the DEF Eprints Service Provider
OAIManager
Full set
Sub set
Librarian
DEF Portal User
OAIHarvester
Open Archives Initiative Data Providers
MYSQL
Z39.50
OAI-PMH
Eprint Service Provider
Zebraserve
r
Web UIw/
Z39.50
InfoNetUserZebra
server
Web UIw/
Z39.50
EXPORT
Protocol for Metadata Harvesting
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DEF-XWS Eprints
OAIManager
Full set
Sub set
Librarian
DEF Portal User
OAIHarvester
Open Archives Initiative Data Providers
MYSQL
Z39.50
OAI-PMH
Eprint Service Provider
Zebraserve
r
Web UIw/
Z39.50
InfoNetUserZebra
server
Web UIw/
Z39.50
EXPORT
Fedora server
Zebra server
Full text retrieval
Batch ingest
EXPORT
AppXYZ User
DEF-XWS Eprints User
DEF-XWS Eprints User
SOAP/REST
Web UIw/SOAP
javaWeb UIw/REST
php
AppXYZw/SOAP
perl
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DEF-XWS EprintsZebraForFedora, a module for Fedora (http://www.indexdata.dk/zebra)
Purpose: to obtain powerful text index and search functionality and performance.
The original text index and search functionality in Fedora is simple SQL on a table, where DC element texts are stored in fields.
ZebraForFedora is a set of Java classes that deploys over existing Fedora and Zebra installations by the running of an Ant target.
In the Fedora configuration file:
<module role="fedora.server.search.FieldSearch" class="dk.defxws.eprints.fedora.server.search.FieldSearchZebraModule"><comment>Instead of fedora.server.search.FieldSearchSQLModule</comment> <datastore id="zebra"> <comment>Zebra server</comment> <param name="host" value="defxws.cvt.dk"/> <param name="port" value="9395"/> </datastore>
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DEF-XWS Eprints
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Purpose achieved Fedora hands-on and experience web services hands-on and experience DEF-XWS Eprints available from web services
http://defxws.cvt.dk:8082/fedora/access/soap?wsdl http://defxws.cvt.dk:8082/fedora/accessDEF-XWS/soap?
wsdl ready for 3-layered system architecture
applications combining many web services
Lesson Do not override field search, provide generic search service instead ...
DEF-XWS Eprints
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Generic Search Service
• Core Fedora Repository Service• new services are deployed as web applications (.war files), with a
configuration file.• The Generic Search Service shall be a webapp, configurable to use
an existing Fedora repository and an existing installation of an indexing and searching engine, like Zebra, Lucene, and others.
• Functionality to be decided by a working group of Fedora users and developers.
Generic
Lucene
Zebra ...
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Generic Search Service
•preliminary analysis of what has been done by others already, approaches and issues people have taken in the following areas
a. what kinds of search engines?b. how is indexing done and how is it kept up to date?c. configuration options? How can you specify what datastreams/disseminations
to index?d. what interfaces for doing searches?e. how do you deal with security in terms of the service interacting with Fedora?f. what are problems with current approaches?g. what would be desirable in a generic search service that would be delivered
with Fedora?
•gathering of requirements and issues for moving towards a reference implementation
- ZebraForFedora may serve as a reference implementation
•from a broader perspective, how to deal with search for federations of repositories
- P2P search in EU project Alvis may be relevant
•things that the Fedora Dev Team might need to do for new services in the Framework:
- a notification/messaging module in the core Fedora repository service so that other services can find out when objects are added or changed.
- how the services run securely with Fedora, a Basic Auth approach is used now
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Repository Federation
Idea under elaboration:
Fedora as Superpeer in an ALVIS peer-to-peer system
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DEF-XWS
Thank you!
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future
DEF-XWS Pilot Web Service-Oriented Architecture
Graphics from Web Services: A Manager's Guide, by Anne Thomas Manes, Addison-Wesley, 2003
DEF-XWS PilotDEF-XWS Pilot
Java Eprint WSphp Test UI
Java Test UISimple Object Access Protocol
or RESTRepresentational State Transfer
Web Services Description Language
http://host/fedora/ws/soap?wsdl
DEF-XWS Eprints