Realtime Get: Under high concurrent indexing and immediate get, a get might be missed while flushing, closes #1344.

modules/elasticsearch/src/main/java/org/elasticsearch/index/engine/robin/RobinEngine.java

@@ -783,7 +783,7 @@ public class RobinEngine extends AbstractIndexShardComponent implements Engine {
         }
 
         try {
-
+            boolean makeTransientCurrent = false;
             if (flush.full()) {
                 rwl.writeLock().lock();
                 try {
@@ -845,10 +845,10 @@ public class RobinEngine extends AbstractIndexShardComponent implements Engine {
                                     // we did not commit anything, revert to the old translog
                                     translog.revertTransient();
                                 } else {
-                                    translog.makeTransientCurrent();
+                                    makeTransientCurrent = true;
                                 }
                             } else {
-                                translog.makeTransientCurrent();
+                                makeTransientCurrent = true;
                             }
                         } catch (Exception e) {
                             translog.revertTransient();
@@ -864,13 +864,21 @@ public class RobinEngine extends AbstractIndexShardComponent implements Engine {
                 }
             }
             refreshVersioningTable(threadPool.estimatedTimeInMillis());
+            // we need to move transient to current only after we refresh
+            // so items added to current will still be around for realtime get
+            // when tans overrides it
+            if (makeTransientCurrent) {
+                translog.makeTransientCurrent();
+            }
             try {
                 SegmentInfos infos = new SegmentInfos();
                 infos.read(store.directory());
                 lastCommittedSegmentInfos = infos;
             } catch (Exception e) {
+                if (!closed) {
                     logger.warn("failed to read latest segment infos on flush", e);
                 }
+            }
         } finally {
             flushing.set(false);
         }

modules/test/integration/src/test/java/org/elasticsearch/test/stress/get/GetStressTest.java

@@ -0,0 +1,96 @@
+/*
+ * Licensed to Elastic Search and Shay Banon under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Elastic Search 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.elasticsearch.test.stress.get;
+
+import org.elasticsearch.action.get.GetResponse;
+import org.elasticsearch.common.settings.ImmutableSettings;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.unit.TimeValue;
+import org.elasticsearch.common.util.concurrent.jsr166y.ThreadLocalRandom;
+import org.elasticsearch.node.Node;
+import org.elasticsearch.node.NodeBuilder;
+
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicLong;
+
+public class GetStressTest {
+
+    public static void main(String[] args) throws Exception {
+        Settings settings = ImmutableSettings.settingsBuilder()
+                .put("index.number_of_shards", 2)
+                .put("index.number_of_replicas", 1)
+                .build();
+
+        final int NUMBER_OF_NODES = 2;
+        final int NUMBER_OF_THREADS = 50;
+        final TimeValue TEST_TIME = TimeValue.parseTimeValue("10m", null);
+
+        Node[] nodes = new Node[NUMBER_OF_NODES];
+        for (int i = 0; i < nodes.length; i++) {
+            nodes[i] = NodeBuilder.nodeBuilder().settings(settings).node();
+        }
+
+        final Node client = NodeBuilder.nodeBuilder()
+                .settings(settings)
+                .client(true)
+                .node();
+
+        client.client().admin().indices().prepareCreate("test").execute().actionGet();
+
+        final AtomicBoolean done = new AtomicBoolean();
+        final AtomicLong idGenerator = new AtomicLong();
+        final AtomicLong counter = new AtomicLong();
+
+        Thread[] threads = new Thread[NUMBER_OF_THREADS];
+        for (int i = 0; i < threads.length; i++) {
+            threads[i] = new Thread(new Runnable() {
+                @Override public void run() {
+                    ThreadLocalRandom random = ThreadLocalRandom.current();
+                    while (!done.get()) {
+                        String id = String.valueOf(idGenerator.incrementAndGet());
+                        client.client().prepareIndex("test", "type1", id)
+                                .setSource("field", random.nextInt(100))
+                                .execute().actionGet();
+
+                        GetResponse getResponse = client.client().prepareGet("test", "type1", id)
+                                //.setFields(Strings.EMPTY_ARRAY)
+                                .execute().actionGet();
+                        if (!getResponse.exists()) {
+                            System.err.println("Failed to find " + id);
+                        }
+
+                        long count = counter.incrementAndGet();
+                        if ((count % 10000) == 0) {
+                            System.out.println("Executed " + count);
+                        }
+                    }
+                }
+            });
+        }
+        for (Thread thread : threads) {
+            thread.start();
+        }
+
+        Thread.sleep(TEST_TIME.millis());
+
+        System.out.println("test done.");
+        done.set(true);
+    }
+}

modules/test/integration/src/test/java/org/elasticsearch/test/stress/get/MGetStress1.java

@@ -17,7 +17,7 @@
  * under the License.
  */
 
-package org.elasticsearch.test.stress.mget;
+package org.elasticsearch.test.stress.get;
 
 import org.elasticsearch.action.get.MultiGetItemResponse;
 import org.elasticsearch.action.get.MultiGetResponse;