[JCR-1359] Adding nodes from concurrently running sessions cause exceptions

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.3.3, 1.4, core 1.4.1
• Fix Version/s: core 1.4.2
• Component/s: jackrabbit-core
• Assignee: Stefan Guggisberg
• Reporter: Alexander Nesterov
• Created: 01/Feb/08 16:18
• Updated: 28/Mar/08 09:15
• Resolved: 07/Mar/08 14:35

Description

Exceptions are thrown when trying to add child nodes to one parent node from different sessions running concurrently. One of the following exceptions is always thrown:

• Exception in thread "Thread-8" java.lang.RuntimeException: javax.jcr.nodetype.ConstraintViolationException: /A/7 needs to be saved as well.
• Exception in thread "Thread-8" java.lang.RuntimeException: javax.jcr.RepositoryException: /A: unable to update item.: Unable to
  resolve path for item: 016b885a-64aa-45b9-a990-05cbabb4586f/ {http://www.jcp.org/jcr/1.0}

  primaryType: Unable to resolve path for item: 016b885a-64aa-45b9-a990-05cbabb4586f/

  {http://www.jcp.org/jcr/1.0}

  primaryType

According to JCR-584 "Improve handling of concurrent node modifications" the following scenario "session 1 adds or removes child node 'x', session 2 adds or removes child node 'y'" should run gracefully, but the following test constantly fails:

public void testSync() throws Exception
{
Node rootNode = getSession ().getRootNode ();
rootNode.addNode ("A");
rootNode.save();

final Session session1 = getRepository().login (new SimpleCredentials ("userName", "password".toCharArray()));
final Session session2 = getRepository().login (new SimpleCredentials ("userName", "password".toCharArray()));

Thread thread1 = new Thread (new Runnable()
{
public void run()
{
try

{ addNodes ("A", session1, 0); }

catch (RepositoryException ex)

{ throw new RuntimeException (ex); }
}
});

Thread thread2 = new Thread (new Runnable()
{
public void run()
{
try
{ addNodes ("A", session2, 1001); }
catch (RepositoryException ex)
{ throw new RuntimeException (ex); }

}
});

thread1.start();
thread2.start();

thread1.join();
thread2.join();
}

private void addNodes (String parentName, Session session, int startIndex)
throws RepositoryException
{
Node parentNode = session.getRootNode().getNode (parentName);
for (int i = startIndex; i < startIndex + 100; i++)

{ String name = Integer.toString (i); parentNode.addNode (name); parentNode.save(); }

}

BTW: exceptions were also thrown when I tried to add nodes from one thread and remove some of them from another one. Each thread used it's own session, each node had unique name.