Fedora Repository 3.2.1 Documentation : Upgrading from 2.x

This document explains how to migrate your Fedora repository from version 2.x to 3.x. Although it is written assuming 3.2.1, the same instructions apply if you are upgrading to an older 3.x release. Before continuing, you should familiarize yourself with the new Content Model Architecture. A basic understanding of how the CMA works will be helpful in understanding the migration process.

Throughout this guide, OLD_FEDORA_HOME refers to the home directory of your Fedora 2.x installation, and NEW_FEDORA_HOME refers to the home directory of your new Fedora 3.x installation.

NOTE: To reduce confusion during this process, if you have previously ingested the Fedora demo objects, you should purge them from your 2.x repository before starting with the migration process. The demo objects have changed significantly since 2.x, and if you'd like the new versions, we recommend that you ingest them after performing a successful migration of your old repository.

1. Install, Start, and Stop Fedora 3.x

Follow the instructions in the Fedora Installation and Configuration Guide. When finished, start the server and verify your installation was successful by visiting the describeRepository page (e.g. http://localhost:8080/fedora/describe). Finally, shut down Fedora. It should not be restarted again until later in the migration process.

2. Point Fedora 3.x to Existing Objects

A. Object XML (FOXML)

Determine where your old object XML is stored. If you're unsure, consult OLD_FEDORA_HOME/server/config/fedora.fcfg and find the value of object_store_base.

Edit NEW_FEDORA_HOME/server/fedora.fcfg and change the value of object_store_base the full path of your old object's directory.

NOTE: The upgrade process will transform the objects in object_store_base of NEW_FEDORA_HOME/server/fedora.fcfg in place. Thus, by following the above instructions, the new upgraded files will exist in their old location. If that is not what is desired, then you could copy the old files (both objects and content) to their final location, point the NEW_FEDORA_HOME/server/fedora.fcfg to that new location, and then continue the update process.

B. Managed Datastreams

Determine where your old Fedora Repository's managed Datastreams are stored. Again, you can check your old fedora.fcfg file. Look for the value of datastream_store_base.

Edit NEW_FEDORA_HOME/server/fedora.fcfg and change the value of datastream_store_base the full path of your old Datastreams directory.

2. Install the Migration Utilities

The migration utilities come as a separate download from the Fedora installation. They are all included, with source, in a single download fedora-migration-3.2.zip at sourceforge.net. Once unzipped, you will find the executable jars in the top directory.

3. Run the Analyzer

The analyzer examines all of your existing digital objects and looks for similarities. It outputs the following information in a directory you specify.

A. Configuring the Analyzer

Create a file (e.g. migration.properties) with the following content, filling in values appropriate to your environment:

# This is the directory where the analyzer's output files should be sent.
# If it doesn't already exist, it will be automatically created.
# If it already exists, it must be empty (to avoid accidental overwrites)
# To disable the above restriction, uncomment clearOutputDir=true below.
outputDir=c:\\fedora-migration
#clearOutputDir=true

# The Fedora 3.x home directory.
fedoraHome=c:\\fedora-3.2.1

# The full path to the JDBC driver Fedora is configured to use.
# NOTE: The analyzer only uses the database to aid in looking up
# the location of FOXML. It will populate the initial paths in
# the database the first time it runs, if the necessary.
jdbcJar=c:\\fedora-3.2.1\\tomcat\\webapps\\fedora\\WEB-INF\\lib\\postgresql-8.3-603.jdbc3.jar
# Aspects of the original objects to ignore for the purpose of
# classification. This is optional. If unspecified, the generated
# content models will be the MOST SPECIFIC POSSIBLE. If
# specified, this property must consist of a space-delimited
# list of any of the following:
# OrigContentModel
# If specified, objects that have differing values in the original
# contentModel property may be assigned to the same content
# model if they are otherwise similar.
# DatastreamIDs
# If specified, only datastreams bound to disseminators will
# be considered important for classification. Objects that have
# differing sets of UNUSED datastream IDs may be assigned to
# the same content model if they are otherwise similar.
# MIMETypes
# If specified, the MIMETYPE of each candidate datastream
# will be ignored for the purpose of classification. Objects that
# have differing MIME types for the same datastream may be
# assigned to the same content model if they are otherwise
# similar.
# FormatURIs
# This works exactly the same as MIMETypes, but applies to
# the FORMAT_URI of candidate datastreams.
#ignoreAspects=OrigContentModel DatastreamIDs MIMETypes FormatURIs

# Specific datastream IDs to ignore for the purpose of classification.
# This is optional. If specified, this property must consist of a
# space-delimited list of datastream IDs to ignore. Note: This configuration
# has no effect if DatastreamIDs is already specified as an ignoreAspect
# above.
ignoreDatastreamIDs=DC RELS-EXT RELS-INT POLICY

# Explicitly declare objects to be in the FedoraObject-3.0 content model.
# The default is 'false', or implicit. If left implicit, the objects
# will not have an explicit basic model, and it will be up to the
# system to use a default value at runtime. This option may have
# an impact on future upgrades. Future versions of Fedora may adopt a new
# basic model that has additional system methods, or require certain
# datastreams or formats. Objects that explicitly declare a 3.0
# model should behave exactly the same if Fedora is upgraded to a
# post 3.0 version. If left implicit, the objects may be interpreted
# in light of the new model, and may inherit new methods, or may
# fail validation and require updating if the new model introduces
# requirements they do not fulfill.

# Uncomment to force explicit basic model declarations in the
# upgraded objects.
# explicitBasicModel = true

B. Analyzer Usage

The analyzer utility is an executable jar and takes the configuration file as a parameter. For example, if your configuration is in the current directory and is named migration.properties, enter the following:

java -jar analyzer.jar migration.properties

Analysis of small repositories will finish very quickly. For repositories with millions of objects, analysis will take several hours. With modern hardware, expect a rate of about 10,000 objects per minute.

C. Reviewing Analyzer Output

Generated content models will be in FOXML 1.1 format and will be named cmodel-n.xml (where n is a number used for association). For each of these, there will be an associated cmodel-n.members.txt file containing a list of PIDs that conform to the content model.

D. Customizing Content Model PIDs

By default, the PIDs assigned to the generated content models are of the form, changeme:CModelN. You should change these to use your own repository's namespace. You may also want to change the identifier part of the PID (e.g. myns:Journal).

To do this, open each cmodel-n.xml file in an editor and change the following as desired:

E. Customizing Service Deployment PIDs

If any cmodel-n-deployments.txt files were created by the analyzer, you should also change any NEW_DEPLOYMENT pid values specified within each before continuing. These PIDs will default to values like changeme:CModel1-BMech1, but again, you should specify your own (e.g. myns:Journal-DefaultImpl).

F. Upgrading Objects Without Content Models

By default, the analyzer ensures that every data object is assigned to a content model. If you'd rather avoid assigning an explicit content model to an object, you may do so by a) removing its PID from the cmodel-n-members.txt file in which it resides and b) adding it to the nocmodel.txt file. This may be done for any number of objects.

5. Run the Generator

The generator reads the output of the analyzer (along with any customizations you have made) and adds the following to the same directory:

A. Configuring the Generator

Like the analyzer, the generator accepts a Java properties file for configuration.

The configuration file should have the following content, with values filled in appropriate to your environment.

# This is the directory containing the analyzer's output, and where the generator's
# results should be written.
sourceDir=c:\\fedora-migration

# The Fedora 3.x home directory
fedoraHome=c:\\fedora-3.2.1

# The full path to the JDBC driver Fedora is configured to use
jdbcJar=c:\\fedora-3.2.1\\tomcat\\webapps\\fedora\\WEB-INF\\lib\\postgresql-8.3-603.jdbc3.jar

B. Generator Usage

The generator utility also accepts the configuration file as a parameter. For example:

java -jar generator.jar migration.properties

The generator should finish very quickly, regardless of the size of the repository.

C. Reviewing Generator Output

The generator will produce several files in the output directory. These files, along with those already produced by the analyzer, will be used in the next steps of the migration process.

One stylesheet will be written for each PID list: sdeps.xslt, sdefs.xslt, nocmodel.xslt, and each cmodel-n.members.xslt file. Each of these stylesheets will include transformation rules for upgrading the objects to FOXML1.1 and adding the necessary fedora-model:hasModel relationship via RELS-EXT, if necessary.

The output will also include a new, generated Service Deployment object (cmodel-n.deploymentN.xml) for each one listed in the input's cmodel-n.deployments.txt files. This SDep will match the content of the source SDep in the repository, but it will have a different PID, will be in FOXML 1.1 format, and will use input part names consistent with the Datastream IDs specified in the associated content model's DS-COMPOSITE-MODEL Datastream.

6. Run the Transformer

The transformer applies stylesheets to FOXML stored in a Fedora repository. Although it directly accepts the output of the analyzer and generator, it can also be used outside of the migration process for making low-level changes to batches of objects. When running the transformer in this way, the repository should be shut down, and the rebuilder should be run immediately afterward (see section below).

Here's how the transformer works: It scans a directory for PID list files, ending with .txt. For each, if a .xslt file exists with the same name, that stylesheet is applied to the repository's FOXML for each object in the PID list.

A. Configuring the Transformer

Like the analyzer and generator, the transformer accepts a Java properties file for configuration. The transformer is configured with the same properties that the generator is configured with (see above), and also takes the following:

# Whether to run the transformer in "dry run" mode or not.
# In dry run mode, transformation will be tested but no changes will be written
dryRun=true

Although not required, it is strongly recommended that you run the transformer with dryRun=true the first time, to ensure all transformations will fully succeed.

B. Transformer Usage

The transformer utility also takes the configuration file as a parameter. For example:

java -jar transformer.jar migration.properties

Transformation will take roughly double the time that analysis took, since it must read and write each file in the repository.

7. Run the Rebuilder

Now that all of your existing objects have been upgraded, you need to run the rebuilder so Fedora's database is up-to-date with the files on disk. See the Rebuilder documentation for further details.

Rebuilding the SQL database will take around double the time that the transformer took. Rebuilding the Resource Index may take significantly longer.

8. Ingest Generated Objects

After the rebuilder has run successfully, you should restart your Fedora 3.x instance and visit the describe page (e.g. http://localhost:8080/fedora/describe) again to make sure it started successfully.

Now you'll need to ingest all the new Content Model and Service Deployment objects created during the analyzer and generator steps. To do this:

10. Verify Success and Clean Up

You should now verify that the upgraded objects are behaving as expected. Pick a few from each cmodel-n.members.txt file and do the following for each:

If you had Disseminators in your original repository, you are now making use of a NEW set of Service Deployment objects. You may now want to purge the original BMechs, since they are no longer in use. The simplest way to do this is with the fedora-admin GUI. The PIDs of the old former BMechs are enumerated in the file sdeps.txt.

Overview