[JCR-2494] Problem with ItemManager shareable node caches, eviction not propagated from one session to another

• Type: Bug
• Status: Patch Available
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.0
• Component/s: jackrabbit-core
• Labels: "shareable cache
• Assignee: Unassigned
• Reporter: Thomas Draier
• Created: 15/Feb/10 19:52
• Updated: 15/Feb/10 20:16

Description

Hi,

When deleting one share of a shareable node from a list with one session, the shareableNodesCache of the other session is not updated on save and the entry is not removed. There's no problem when the item is completely deleted - in that case, the ItemStateListener propagates the event to other sessions to evict the entries from the cach.

This leads to some issues if the item is later retrieved with ItemManager.retrieveItem(id) - this one returns the first entry of the shareableNodesCache, which may be the one that has been deleted. The NodeData here has a primaryParentId - but the node behind this id does not have the shareable node as a child anymore. Subsequent calls to getName() or getPath() on this node throws exception ( failed to build path of xx: yy has no child entry for xx , from NodeImpl:3092)

It's quite difficult to reproduce, and does not crashes everytime (as we're getting one item from the shareableNodesCache map), but we have some scenarios where this happens quite frequently - here's some code to reproduce the problem :

// Create structure
Node n1 = node.addNode("n1", "nt:unstructured");
Node n2 = node.addNode("n2", "nt:unstructured");
Node n3 = node.addNode("n3", "nt:unstructured");
Node n4 = node.addNode("n4", "nt:unstructured");
Node s1 = n1.addNode("s1", "nt:unstructured");

s1.addMixin("mix:shareable");
String id = s1.getIdentifier();
session.save();
session.getWorkspace().clone("default", s1.getPath(), n2.getPath() + "/s2", false);
session.getWorkspace().clone("default", s1.getPath(), n3.getPath() + "/s3", false);
session.getWorkspace().clone("default", s1.getPath(), n4.getPath() + "/s4", false);

// Load caches
session.getNode(node.getPath()+"/n1/s1").getPath();
session.getNode(node.getPath()+"/n2/s2").getPath();
session.getNode(node.getPath()+"/n3/s3").getPath();
session.getNode(node.getPath()+"/n4/s4").getPath();

// Remove shares from other session
session2.getNode(node.getPath()+"/n1/s1").remove();
session2.getNode(node.getPath()+"/n2/s2").remove();
session2.getNode(node.getPath()+"/n4/s4").remove();
session2.save();

assertNotNull(session2.getNodeByIdentifier(id).getPath());
assertNotNull(session.getNodeByIdentifier(id).getPath());

I fixed the issue by adding a call to evictItems() in stateModified (actually, almost uncommenting the code that was already there). You'll find the patch attached.

Regards