Index: oak-jcr/src/test/java/org/apache/jackrabbit/oak/jcr/ConcurrentAddRemove2IT.java
===================================================================
--- oak-jcr/src/test/java/org/apache/jackrabbit/oak/jcr/ConcurrentAddRemove2IT.java	(revision 0)
+++ oak-jcr/src/test/java/org/apache/jackrabbit/oak/jcr/ConcurrentAddRemove2IT.java	(working copy)
@@ -0,0 +1,111 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.jackrabbit.oak.jcr;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+import javax.jcr.Node;
+import javax.jcr.RepositoryException;
+import javax.jcr.Session;
+
+import org.junit.Test;
+
+import static org.junit.Assert.fail;
+
+/**
+ * <code>ConcurrentAddRemove2IT</code>...
+ */
+public class ConcurrentAddRemove2IT extends AbstractRepositoryTest {
+
+    private static final int NUM_WORKERS = 2;
+
+    private static final long RUN_TIME = TimeUnit.SECONDS.toMillis(100);
+
+    public ConcurrentAddRemove2IT(NodeStoreFixture fixture) {
+        super(fixture);
+    }
+
+    @Test
+    public void concurrentIndexUpdate() throws Exception {
+        List<Exception> exceptions = Collections.synchronizedList(new ArrayList<Exception>());
+        // prepare parent structure
+        Node test = getAdminSession().getRootNode().addNode("test", "oak:Unstructured");
+        for (int i = 0; i < 5; i++) {
+            test = test.addNode("level-" + i);
+        }
+        getAdminSession().save();
+        List<Thread> worker = new ArrayList<Thread>();
+        for (int i = 0; i < NUM_WORKERS; i++) {
+            worker.add(new Thread(new Worker(
+                    createAdminSession(), test.getPath(), "child-" + i, exceptions)));
+        }
+        for (Thread t : worker) {
+            t.start();
+        }
+        for (Thread t : worker) {
+            t.join();
+        }
+        for (Exception e : exceptions) {
+            e.printStackTrace();
+            fail(e.toString());
+        }
+    }
+
+    private static final class Worker implements Runnable {
+
+        private final Session s;
+        private final String path;
+        private final String name;
+        private final List<Exception> exceptions;
+
+        Worker(Session s, String path, String name, List<Exception> exceptions) {
+            this.s = s;
+            this.path = path;
+            this.name = name;
+            this.exceptions = exceptions;
+        }
+
+        @Override
+        public void run() {
+            try {
+                long end = System.currentTimeMillis() + RUN_TIME;
+                while (end > System.currentTimeMillis()/* && exceptions.isEmpty()*/) {
+                    s.refresh(false);
+                    Node n = s.getNode(path);
+                    if (n.hasNode(name)) {
+                        n.getNode(name).remove();
+                    } else {
+                        n.addNode(name, "nt:unstructured");
+                    }
+                    try {
+                        s.save();
+                    } catch (RepositoryException e) {
+                        System.out.println(Thread.currentThread().getName() + ": " + e.getCause().getCause().toString());
+                        exceptions.add(e);
+                    }
+                }
+            } catch (RepositoryException e) {
+                exceptions.add(e);
+            } finally {
+                s.logout();
+            }
+        }
+    }
+}

Property changes on: oak-jcr/src/test/java/org/apache/jackrabbit/oak/jcr/ConcurrentAddRemove2IT.java
___________________________________________________________________
Added: svn:eol-style
## -0,0 +1 ##
+native
\ No newline at end of property
Index: oak-jcr/src/test/java/org/apache/jackrabbit/oak/jcr/NodeStoreFixture.java
===================================================================
--- oak-jcr/src/test/java/org/apache/jackrabbit/oak/jcr/NodeStoreFixture.java	(revision 1687113)
+++ oak-jcr/src/test/java/org/apache/jackrabbit/oak/jcr/NodeStoreFixture.java	(working copy)
@@ -166,7 +166,7 @@
         }
 
         public DocumentFixture(String uri) {
-            this(uri, true, null);
+            this(uri, false, null);
         }
 
         public DocumentFixture() {
Index: oak-jcr/src/test/resources/logback-test.xml
===================================================================
--- oak-jcr/src/test/resources/logback-test.xml	(revision 1687113)
+++ oak-jcr/src/test/resources/logback-test.xml	(working copy)
@@ -33,6 +33,7 @@
     <logger name="com.mongodb.tcp" level="ERROR"/>
     <logger name="org.apache.jackrabbit.oak.jcr.operations" level="INFO"/>
     <logger name="org.apache.jackrabbit.oak.security.authentication" level="WARN"/>
+    <logger name="org.apache.jackrabbit.oak.spi.state.AbstractNodeStoreBranch" level="DEBUG"/>
 
     <root level="INFO">
         <!--