NOW AVAILABLE: Fedora 4.7.3 Release

From David Wilcox, Fedora Product Manager, on behalf of the Fedora team

The Fedora Team is proud to announce the release of Fedora 4.7.3 on June 7, 2017. Full release notes are available on the wiki. The Fedora 4.7.3 release is a backwards compatible refinement of the previous release, which fixes a namespace-corrupting bug that has the effect of Fedora being unable to successfully start after having been shut down

• This release requires Java 8
• Downloads
• Javadocs

Team 

Release Manager

• Nick Ruest – York University
• Andrew Woods – DuraSpace 

Developers

• Andrew Woods – DuraSpace
• Aaron Birkland – Johns Hopkins University 

Issue Reporters

• Steven Anderson
• Daniel Sanford Resources

Detailed Bug Remediation Notes 

Who is affected

This occurs when all the following conditions are true:

1. An earlier version of Fedora had been used to create objects, before upgrading to 4.7.1 and 4.7.2
2. One of the objects created in the repository prior to upgrade to 4.7.1 or 4.7.2 contains a triple using one or more of the following namespaces, and the prefix does NOT match the one shown:
   1. skos: http://www.w3.org/2004/02/skos/core#
   2. acl: http://www.w3.org/ns/auth/acl#
   3. iana: http://www.iana.org/assignments/relation/
   4. event: http://fedora.info/definitions/v4/event#
   5. owl: http://www.w3.org/2002/07/owl#
   6. prov: http://www.w3.org/ns/prov#
   7. config: info:fedoraconfig/

For example, if an object prior to upgrade to Fedora 4.7.1 or 4.7.2 looked like the following, it would be OK since the prefix matches the above table:

On the other hand, if an object prior to the upgrade to 4.7.1 or 4.7.2 looked like this, it will cause the namespace corrupting bug:

Viewing the objects in a running 4.7.1 or 4.7.2 instance is insufficient for determining if this bug affects you, as the prefixes that you are shown will not necessarily match the prefixes originally present in the object. If you have any objects containing triples whose predicate or object contains one of the above namespaces, you are at risk.

What is the problem

Fedora 4.7.1 and 4.7.2 added some global, hard-coded namespaces and prefixes to the fedora-node-types.cnd file.  Any existing namespaces that conflict with these new hard-coded namespaces are deleted/overwritten when Fedora exits.  This results in an inconsistent Modeshape database.  The repository will function in this inconsistent state until a re-started is attempted, which will fail.

How to fix the issue

At a high-level you need to: 

1. Take a backup
2. Fix the backup manually
3. Restore the backup into a new repository

Since it is somewhat difficult to determine if your repository is truly affected, a reasonable upgrade plan from 4.7.1 or 4.7.2 to 4.7.3 is:

1. Take a backup
2. Try simply upgrading 4.7.3 over the existing repository.  If it starts up successfully, you are not affected by the issue, and are done!
3. If Fedora 4.7.3 fails to start, then you need to fix the backup manually, and restore into an empty repository How to fix the issue

Detatiled instructions