[JCR-912] OverlappingFileLockException with JRE 1.6

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.3
• Fix Version/s: 1.3.1
• Component/s: jackrabbit-core
• Environment: Linux + Java6; however, per http://blogs.sun.com/DaveB/date/200612, this may be a problem on all Java6 platforms
• Assignee: Stefan Guggisberg
• Reporter: Patrick Haggood
• Created: 11/May/07 13:13
• Updated: 10/Sep/07 16:26
• Resolved: 18/May/07 15:04

Description

Per email discussion:
On Mon, 2007-02-26 at 10:26 +0100, Marcel Reutegger wrote:
> > just my 2c, I didn't really investigated this issue in more detail...
> >
> > according to the javadoc of FileChannel.tryLock() the
> > OverlappingFileLockException is thrown if the JVM already holds a lock on the
> > channel.
> >
> > in contrast, the current check in the repository startup method primarily
> > focuses on the situation where two JVMs start a repository on the same home
> > directory.
> >
> > I'd say the OverlappingFileLockException is thrown because two repository
> > instances are startup within the same JVM using the same repository home
> > directory.
> >
> > I suggest we add a catch clause, which also covers OverlappingFileLockException
> > in addition to IOException.
> >
> > regards
> > marcel
> >
> > Stefan Guggisberg wrote:
> > > btw, afaik OverlappingFileLockException is only thrown on linux,
> > > FileChannel#getLock on windows e.g. returns null in the same situation.
> > >
> > > you might want to test on a different platform to further isolate the
> > > issue.
> > > you could also place a breakpoint at the top of the
> > > RepositoryImpl#acquireRepositoryLock
> > > method, step through the code, verify the contents of your fs etc.
> >
>

=== Original email

On 2/19/07, Patrick Haggood <codezilla@> wrote:
I'm using Linux, Sun Java 6 and Jackrabbit 1.3 with Derby persistance.
I have a putNode(object) function that's giving the above error in unit
tests. It always fails after the second update, even when I swap tests
(i.e. save user doc then save user). Prior to each test, I delete the
repository directory.

Do I need to set explicit locks before/after each session.save()?

• • • • • • • • • • • Unit Test
                      DBConn dbc;

public SessionUtilTest(String testName)

{ super(testName); dbc = new DBConn(); }

// Note - putUser and putDocument both use putNode after determining
which rootnode will be used

/**

• Test of putUnityUser method, of class unityjsr170.jr.SessionUtil.
  */
  public void testPutUnityUser() { System.out.println("putUnityUser"); UnityUser usr = usr1; SessionUtil instance = dbc.getSutil(); String result = instance.putUnityUser(usr1); assertNotNull(result); usr = (UnityUser) instance.getUnityUserByID(result); assertEquals(usr1.getName(),usr.getName()); }

/**

• Test of putUnityDocument method, of class
  unityjsr170.jr.SessionUtil.
  */
  public void testPutUnityDocument() { System.out.println("putUnityDocument"); UnityDocument udoc = adr1; SessionUtil instance = dbc.getSutil(); String result = instance.putUnityDocument(udoc); <---- File Lock Error assertNotNull(result); udoc = (UnityDocument) instance.getUnityDocumentByID(result); assertEquals(adr1.getName(),udoc.getName()); }

• • • • • • • • • Here's where I setup my repository connection

public DBConn(){
sutil = null;
try

{ rp = new TransientRepository(); sutil= new SessionUtil(rp); }

catch (IOException ex)

{ ex.printStackTrace(); }
}

public void shutdown(){ sutil.closeAll(); }

public SessionUtil getSutil(){ return sutil; }

**************** SessionUtil

public SessionUtil(Repository rp){
try { session = rp.login(new SimpleCredentials("username","password".toCharArray())); } catch (LoginException ex) { ex.printStackTrace(); }

catch (RepositoryException ex)

{ ex.printStackTrace(); }

}

public void closeAll(){
try

{ session.logout(); }

catch (Exception ex)

{ ex.printStackTrace(); System.out.println("Error closing repository"); }

}

// Put a node on the tree under the root node, return the uuid of the
new or updated node
private String putNode(String nodetype, UnityBaseObject ubo){
String resultuuid =null;
String uname = ubo.getName();
String utype = ubo.getType();
String objectuid = ubo.getId();
Node pnode; // node to add or update
Session ses = null;
try {
ses = getSession();
// Does updateable node already have node Id?
if (objectuid==null)

{ Node rn = ses.getRootNode(); pnode = rn.addNode(utype); pnode.addMixin("mix:referenceable"); }

else

{ // grab existing node by uuid pnode = ses.getNodeByUUID(objectuid); }

// Did we get an updateable node?
if (pnode!=null)

{ ubo.setId(pnode.getUUID()); String unityXML = utrans.getXMLStringFromUnityBaseObject(ubo); // update all the properties pnode.setProperty("name",ubo.getName()); pnode.setProperty("type",ubo.getType()); pnode.setProperty("xmldata",unityXML); ses.save(); resultuuid = ubo.getId(); }

} catch(Exception e)

{ e.printStackTrace(); }

return resultuuid;
}

private Session getSession()

{ return session; }

• • • • • • • • • • • • repository.xml

<Workspace name="${wsp.name}">
<FileSystem
class="org.apache.jackrabbit.core.fs.local.LocalFileSystem">
<param name="path" value="${wsp.home}"/>
</FileSystem>
<PersistenceManager
class="org.apache.jackrabbit.core.state.db.DerbyPersistenceManager">
<param name="url" value="jdbc:derby:
${wsp.home}/db;create=true"/>
<param name="schemaObjectPrefix" value="${wsp.name}_"/>
</PersistenceManager>
<SearchIndex
class="org.apache.jackrabbit.core.query.lucene.SearchIndex">
<param name="path" value="${wsp.home}/index"/>
<param name="useCompoundFile" value="true"/>
<param name="minMergeDocs" value="100"/>
<param name="volatileIdleTime" value="3"/>
<param name="maxMergeDocs" value="100000"/>
<param name="mergeFactor" value="10"/>
<param name="bufferSize" value="10"/>
<param name="cacheSize" value="1000"/>
<param name="forceConsistencyCheck" value="false"/>
<param name="autoRepair" value="true"/>
<param name="analyzer"
value="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
</SearchIndex>
</Workspace>

Issue Links

• is duplicated by: JCR-919 java.nio.channels.OverlappingFileLockException