Details
Major Description
I'm not sure of exact set of event that led to an incident on one of our test clusters. The cluster is running 3 AEM instances based on oak build at 1.3.10.r1713699 backed by a single mongo 3 instance.
Unfortunately, we found the issue too late and logs had rolled over. Here's the exception that showed over and over as workflow jobs were (trying to) being processed:
....
at java.lang.Thread.run(Thread.java:745)
Caused by: javax.jcr.InvalidItemStateException: OakMerge0004: OakMerge0004: The node 8:/oak:index/event.job.topic/:index/com%2Fadobe%2Fgranite%2Fworkflow%2Ftransient%2Fjob%2Fetc%2Fworkflow%2Fmodels%2Fdam-xmp-writeback%2Fjcr_content%2Fmodel/var/eventing/jobs/assigned was already added in revision
r151233e54e1-0-4, before
r15166378b6a-0-2 (retries 5, 6830 ms)
at org.apache.jackrabbit.oak.api.CommitFailedException.asRepositoryException(CommitFailedException.java:239)
at org.apache.jackrabbit.oak.api.CommitFailedException.asRepositoryException(CommitFailedException.java:212)
at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.newRepositoryException(SessionDelegate.java:669)
at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.save(SessionDelegate.java:495)
at org.apache.jackrabbit.oak.jcr.session.SessionImpl$8.performVoid(SessionImpl.java:419)
at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.performVoid(SessionDelegate.java:273)
at org.apache.jackrabbit.oak.jcr.session.SessionImpl.save(SessionImpl.java:416)
at org.apache.sling.jcr.resource.internal.helper.jcr.JcrResourceProvider.commit(JcrResourceProvider.java:634)
... 16 common frames omitted
Caused by: org.apache.jackrabbit.oak.api.CommitFailedException: OakMerge0004: OakMerge0004: The node 8:/oak:index/event.job.topic/:index/com%2Fadobe%2Fgranite%2Fworkflow%2Ftransient%2Fjob%2Fetc%2Fworkflow%2Fmodels%2Fdam-xmp-writeback%2Fjcr_content%2Fmodel/var/eventing/jobs/assigned was already added in revision
r151233e54e1-0-4, before
r15166378b6a-0-2 (retries 5, 6830 ms)
at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.merge0(DocumentNodeStoreBranch.java:200)
at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.merge(DocumentNodeStoreBranch.java:123)
at org.apache.jackrabbit.oak.plugins.document.DocumentRootBuilder.merge(DocumentRootBuilder.java:158)
at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStore.merge(DocumentNodeStore.java:1497)
at org.apache.jackrabbit.oak.core.MutableRoot.commit(MutableRoot.java:247)
at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.commit(SessionDelegate.java:346)
at org.apache.jackrabbit.oak.jcr.delegate.SessionDelegate.save(SessionDelegate.java:493)
... 20 common frames omitted
Caused by: org.apache.jackrabbit.oak.plugins.document.ConflictException: The node 8:/oak:index/event.job.topic/:index/com%2Fadobe%2Fgranite%2Fworkflow%2Ftransient%2Fjob%2Fetc%2Fworkflow%2Fmodels%2Fdam-xmp-writeback%2Fjcr_content%2Fmodel/var/eventing/jobs/assigned was already added in revision
r151233e54e1-0-4, before
r15166378b6a-0-2
at org.apache.jackrabbit.oak.plugins.document.Commit.checkConflicts(Commit.java:582)
at org.apache.jackrabbit.oak.plugins.document.Commit.createOrUpdateNode(Commit.java:487)
at org.apache.jackrabbit.oak.plugins.document.Commit.applyToDocumentStore(Commit.java:371)
at org.apache.jackrabbit.oak.plugins.document.Commit.applyToDocumentStore(Commit.java:265)
at org.apache.jackrabbit.oak.plugins.document.Commit.applyInternal(Commit.java:234)
at org.apache.jackrabbit.oak.plugins.document.Commit.apply(Commit.java:219)
at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.persist(DocumentNodeStoreBranch.java:290)
at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.persist(DocumentNodeStoreBranch.java:260)
at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.access$300(DocumentNodeStoreBranch.java:54)
at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch$InMemory.merge(DocumentNodeStoreBranch.java:498)
at org.apache.jackrabbit.oak.plugins.document.DocumentNodeStoreBranch.merge0(DocumentNodeStoreBranch.java:180)
... 26 common frames omitted
....
Doing following removed repo corruption and restored w/f processing:
oak.removeDescendantsAndSelf("/oak:index/event.job.topic/:index/com%2Fadobe%2Fgranite%2Fworkflow%2Ftransient%2Fjob%2Fetc%2Fworkflow%2Fmodels%2Fdam-xmp-writeback%2Fjcr_content%2Fmodel/var/eventing/jobs/assigned")
Attaching mongoexport output
for /oak:index/event.job.topic/:index/com%2Fadobe%2Fgranite%2Fworkflow%2Ftransient%2Fjob%2Fetc%2Fworkflow%2Fmodels%2Fdam-xmp-writeback%2Fjcr_content%2Fmodel/var/eventing/jobs/assigned/6a389a6a-a8bf-4038-b57b-cb441c6ac557/com.adobe.granite.workflow.transient.job.etc.workflow.models.dam-xmp-writeback.jcr_content.model/2015/11/19/23/54/6a389a6a-a8bf-4038-b57b-cb441c6ac557_10 (the hierarchy created at r151233e54e1-0-4). I've renamed a few path elements to make it more reable though (e.g. :index/com%2Fadobe%2Fgranite%2Fworkflow%2Ftransient%2Fjob%2Fetc%2Fworkflow%2Fmodels%2Fdam-xmp-writeback%2Fjcr_content%2Fmodel -> enc_value).
mreutegg, I'm assigning it to myself for now, but I think this would require your expertise all the way 
.
