Hello everybody, I got a question about Clustering Jackrabbit (v 1.6.2). I'm trying to figure out how the clustering schematics works. I got a custom in-memory database that I integrated with Jackrabbit: I already got custom PersistenceManager and FileSystem implementations plus some other required classes. They are working fine since I got my test repositories running with all functionality.
The new feature that I want to support is Clustering. I started implementing my custom Journal class, extending from AbstractJournal, but there are some points that I really don't get. I start 2 repositories/cluster nodes in the same machine but with different configurations. Each repo has it's own unique ID and I think they are compliant to the configuration rules stated here ( http://wiki.apache.org/jackrabbit/Clustering) since both repos start without any problems. I try to add content to one of the repos like this: ========================== JAVA CODE ===================================== Workspace ws = session.getWorkspace(); List<String> prefixes = Arrays.asList(ws.getNamespaceRegistry().getPrefixes()); if( prefixes == null || !prefixes.contains("wiki")){ ws.getNamespaceRegistry().registerNamespace("wiki"," http://www.barik.net/wiki/1.0";); } Node rootNode = keepAliveSession.getRootNode(); Node encyclopedia = null; if(!rootNode.hasNode("wiki:encyclopedia")){ encyclopedia = rootNode.addNode("wiki:encyclopedia"); } else{ encyclopedia = rootNode.getNode("wiki:encyclopedia"); } ========================== END OF JAVA CODE =============================== At this point, even before saving the session, a new Record is created and stored in the shared Journal thus creating a new Revision. On the synchronization thread of the other repo, I can see it retrieves this new Revision record(NamespaceRecord) from the Journal and it's NamespaceRegistryImpl updates two files: ns_reg.properties and ns_idx.properties. Both repos are now synced to the Journal (revision 1, at this point). In the same session I continue to add some more dummy content: ========================== JAVA CODE ===================================== for (int i = 0; i < iterations; i++) { Node p = encyclopedia.addNode("wiki:entry"); p.setProperty("wiki:title", new StringValue("Rose " + i)); p.setProperty("wiki:content", new StringValue("A rose is a flowering shrub. " + i)); p.setProperty(JcrConstants.JCR_LASTMODIFIED, System.currentTimeMillis()); } session.save(); ========================== END OF JAVA CODE =============================== No this is where things starts to get fuzzy. First of all, the new nodes are only "flushed" when the session is saved, what is not the case with the Namespace. Okay, after the session is saved, the synchronization thread of the other repo get's a ChangeLogRecord from the Journal with a bunch of changes. The SharedItemStateManager comes into play and persists the new changes ... or at least it was suppose to. I cannot track/find where it actually does it! I really don't get anything more by this point. The LockManagerImpl, SearchManager also consume the events but I don't know what it does exactly. Anyway ... I can't understand how this mechanism works. I need to find the method that invokes the PersistenceManager for persisting the new items found in the Journal's records. Can anybody give me a light on this issue? I just found this that might help me: http://jackrabbit.apache.org/jackrabbit-architecture.html Thanks a lot. Cheers -- Met vriendelijke groet, Tricode Professional Services BV William R. J. Ribeiro Developer T: +31 (0)318 55 92 10 F: +31 (0)318 65 09 09 E: [email protected] W: www.tricode.nl De Schutterij 12, 3905 PL Veenendaal, The Netherlands | KVK 30183142
