Fedora OAI Provider Service

1. About This Service

The Fedora OAI Provider Service is part of the Fedora Service Framework and offers a vast improvement over the previous, simple OAI provider that Fedora used in previous versions. The new provider is based on Proai, an open source caching, polling OAI provider. It has the following features:

• Supports any metadata format available through your Fedora repository via a datastream or dissemination.
• Supports sets that are expressed as RDF relationships in your digital objects' RELS-EXT datastreams as exposed via the Resource Index.
• Runs as a webapp in any servlet container, acting as a web service client to Fedora.
• Caches the content of the Fedora disseminations and datastreams intended to be exposed as OAI records. This allows for fast response times and ensures that the OAI provider can continue to run even when Fedora is temporarily stopped.

NEW FEATURES: This release of the OAI Provider incorportates the following new features:

• Automatic schema validation.
  Incoming record XML can now be automatically validated and rejected if it doesn't conform to the XML schema it declares.
• Support for MPTStore
  As of release 2.2, Fedora now supports an alternate triplestore, MPTStore, for the Resource Index. The OAI Provider service has been modified to support this configuration option. It can now be used whether the RI is backed by Kowari or MPTStore.

2. Installation

To install the service:

1. Make sure you have a suitable database installed (MySQL, PostgreSQL, Oracle, or McKoi) and a database user account that can create tables in the database.
2. Make sure your Fedora repository is running with the Resource Index turned ON. This is necessary because the oai provider periodically queries the resource index to discover which records of interest have changed.
3. Deploy the oaiprovider.war file into your servlet container.
4. Configure the OAI provider as described in the Configuration section below.
5. Re-start the webapp (this is often done by restarting the servlet container itself).

3. Demonstration / Test Setup

The source distribution of the OAI Provider Service includes several test Fedora objects. You can use these objects and the default proai.properties configuration file to quickly get an idea for how the service works.

1. Complete installation steps 1-4 above, using most of the default values in the proai.properties configuration file, but making sure that the following properties are set according to your own Fedora installation:
   • driver.fedora.baseURL
   • driver.fedora.user
   • driver.fedora.pass
2. Make sure your Fedora installation is configured to retain (rather than re-generate) PIDs of objects in the "demo" PID namespace on ingest. You can check this in your fedora.fcfg file: If one of the values of "retainPIDs" is "demo" or "*" (asterisk), Fedora is configured correctly. Otherwise, you should add this value and re-start Fedora.
3. Use the fedora-admin GUI or fedora-ingest command-line utility to ingest all foxml objects in the src/test/foxml directory of the Fedora OAI Provider source distribution.
4. Start the webapp.

Upon starting, the service will poll Fedora for objects that provide oai record content and have changed since its last update. It will find the objects you just ingested, request appropriate disseminations of each, and save them in its cache. Once it has successfully completed a cache update cycle, you should be able to hit the front-end (where you installed the service) with OAI-PMH verbs. Here are a couple examples:

http://localhost/oaiprovider/?verb=Identify
http://localhost/oaiprovider/?verb=ListRecords&metadataPrefix=oai_dc

Now try using fedora-admin to edit one of the datastreams of one of the demo objects you just ingested. The next time the oaiprovider service polls Fedora for modified records, it should pick up this change and make it available via the front-end.

Note that the poll frequency is ten minutes by default -- this can be configured to be more or less frequent by changing the proai.driverPollSeconds in the proai.properties file.

4. Configuration

Please consult the OAI Provider Configuration Reference for a complete list of proai.properties configuration options and what they do.

You should also take a look at the log4j.xml that resides alongside the proai.properties file in the webapp's WEB-INF/classes directory. This file controls where log messages will be sent and how much detail they will contain. When first setting up the OAI provider, it is recommended that you keep the log level high (DEBUG for most categories).