Thanks a lot, it is working much better now.
-----Original Message-----
From: Marcel Reutegger [mailto:[email protected]]
Sent: mardi 7 octobre 2014 10:59
To: [email protected]
Subject: Re: OakMerge0001: Failed to merge changes to the underlying store
Hi,
you forgot to shut down the DocumentNodeStore. You need to add this do your
finally clause:
if (nodeStore != null) {
nodeStore.dispose();
}
It isn't intuitive why this leads to this exception, but let me try to explain.
The DocumentNodeStore allows deployments with multiple instances working in a
cluster. Each instance has a unique clusterId, which is maintained in MongoDB
with a lease time. Now, if you just exit without shutting down the store, the
lease is not removed and a subsequent start will use a different clusterId.
This means, the store will look at the data in MongoDB from a different cluster
node point of view.
Changes from other cluster nodes are not visible immediately. Each cluster node
periodically makes its changes visible to others by updating the _lastRev on
the root document in MongoDB. Similarly they pick up other changes
periodically. Per default this happens every second. If you don't shut down the
store you will leave some changes in a state not visible to other cluster nodes
(or as in your case a subsequent startup with a different clusterId). It will
then try to create the initial content again and fail with a conflict because
it is already there, but just not yet visible.
There is a recovery mechanism built into the DocumentNodeStore to make these
kind of changes visible if an instance crashes or is not shut down properly.
However, this process is only triggered when you deploy Oak in an OSGi
container.
See DocumentNodeStoreService.registerLastRevRecoveryJob()
Regards
Marcel
On 06/10/14 18:17, "TALHAOUI Mohamed" <[email protected]> wrote:
>HI,
>
>Sorry if this is not the right place to post but I have an issue with a
>simple POC using Oak 1.1.0 and MongoDB as a node store.
>I would appreciate any help / hints on resolving this issue.
>
>Thanks
>
>I am getting the following exception:
>java.lang.RuntimeException:
>org.apache.jackrabbit.oak.api.CommitFailedException: OakMerge0001:
>OakMerge0001: Failed to merge changes to the underlying store (retries
>5,
>4848 ms)
> at
>org.apache.jackrabbit.oak.spi.lifecycle.OakInitializer.initialize(OakIn
>iti
>alizer.java:64)
> at
>org.apache.jackrabbit.oak.Oak.createContentRepository(Oak.java:551)
> at org.apache.jackrabbit.oak.jcr.Jcr.createRepository(Jcr.java:196)
> at com.rsd.glass.oak.Poc.main(Poc.java:44)
>Caused by: org.apache.jackrabbit.oak.api.CommitFailedException:
>OakMerge0001: OakMerge0001: Failed to merge changes to the underlying
>store (retries 5, 4848 ms)
> at
>org.apache.jackrabbit.oak.spi.state.AbstractNodeStoreBranch.merge(Abstr
>act
>NodeStoreBranch.java:341)
> at
>org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.merg
>e(D
>ocumentNodeStoreBranch.java:161)
> at
>org.apache.jackrabbit.oak.plugins.document.DocumentRootBuilder.merge(Do
>cum
>entRootBuilder.java:159)
> at
>org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore.merge(Docu
>men
>tNodeStore.java:1290)
> at
>org.apache.jackrabbit.oak.spi.lifecycle.OakInitializer.initialize(OakIn
>iti
>alizer.java:62)
>
>Here is my code:
>
>public class Poc {
>
> public static void main(String args[]) {
>
> Session session = null;
> try {
> MongoConnection connection = new
>MongoConnection("127.0.0.1", 27017, "oak");
> DB db = connection.getDB();
>
> DocumentMK.Builder builder = new DocumentMK.Builder();
> builder.setMongoDB(db);
>
> NodeStore nodeStore = new DocumentNodeStore(builder);
> Repository repository = new
>Jcr(nodeStore).createRepository();
> session = repository.login(new
>SimpleCredentials("admin", "admin".toCharArray()));
>
> Poc poc = new Poc();
>
> NodeTypeManager ntm =
>session.getWorkspace().getNodeTypeManager();
> CndImporter.registerNodeTypes(new
>FileReader("src/main/resources/myMetadata.cnd"), session, true);
>
> poc.buildContent(session, poc, ntm);
>
> session.save();
>
> // Retrieve content
> Node rootNode = session.getRootNode();
> Node node = rootNode.getNode("Policies/HR/Contracts");
> System.out.println(node.getPath());
>
> System.exit(0);
> } catch (Exception e) {
> // TODO Auto-generated catch block
> e.printStackTrace();
> System.exit(-1);
> } finally {
> if (session != null) {
> session.logout();
> }
> }
>
> }
>
> private void buildContent(Session session, Poc poc,
>NodeTypeManager ntm) throws Exception {
>
> if (session.itemExists("/Policies")) {
> session.removeItem("/Policies");
> }
>
> // Create Policies tree
> Node rootNode = session.getRootNode();
> Node policiesNode = rootNode.addNode("Policies",
>"my:policy");
> Node hrNode = policiesNode.addNode("HR", "my:policy");
> hrNode.setProperty("my:metadata", "hr");
> Node contractsNode = hrNode.addNode("Contracts",
>"my:policy");
> contractsNode.setProperty("my:metadata", "contract");
>
> }
>
>}
>
