SOLR-5245: Add a test to ensure that election contexts are keyed off both collection name and coreNodeName so that killing a shard in one collection does not result in leader election in a different collection.

(cherry picked from commit 62bc90d)

solr/CHANGES.txt

@@ -311,6 +311,10 @@ Other Changes
 * SOLR-4531: Add tests to ensure that recovery does not fail on corrupted tlogs.
   (Simon Scofield, Cao Manh Dat via shalin)
 
+* SOLR-5245: Add a test to ensure that election contexts are keyed off both collection name and coreNodeName
+  so that killing a shard in one collection does not result in leader election in a different collection.
+  See SOLR-5243 for the related bug. (Cao Manh Dat via shalin)
+
 ==================  6.2.1 ==================
 
 Bug Fixes

solr/core/src/test/org/apache/solr/cloud/LeaderElectionContextKeyTest.java

@@ -0,0 +1,114 @@
+/*
+ * 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.solr.cloud;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+
+import org.apache.solr.client.solrj.SolrClient;
+import org.apache.solr.client.solrj.SolrServerException;
+import org.apache.solr.client.solrj.impl.HttpSolrClient;
+import org.apache.solr.client.solrj.request.CollectionAdminRequest;
+import org.apache.solr.client.solrj.request.CoreAdminRequest;
+import org.apache.solr.common.cloud.Replica;
+import org.apache.solr.common.cloud.SolrZkClient;
+import org.apache.solr.common.cloud.ZkStateReader;
+import org.apache.zookeeper.KeeperException;
+import org.hamcrest.CoreMatchers;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class LeaderElectionContextKeyTest extends SolrCloudTestCase {
+
+  private static final String TEST_COLLECTION_1 = "testCollection1";
+  private static final String TEST_COLLECTION_2 = "testCollection2";
+
+  @BeforeClass
+  public static void setupCluster() throws Exception {
+    configureCluster(1)
+        .addConfig("config", TEST_PATH().resolve("configsets").resolve("cloud-minimal").resolve("conf"))
+        .configure();
+
+    CollectionAdminRequest
+        .createCollection("testCollection1", "config", 2, 1)
+        .setMaxShardsPerNode(1000)
+        .process(cluster.getSolrClient());
+    CollectionAdminRequest
+        .createCollection("testCollection2", "config", 2, 1)
+        .setMaxShardsPerNode(1000)
+        .process(cluster.getSolrClient());
+    AbstractDistribZkTestBase.waitForRecoveriesToFinish("testCollection1", cluster.getSolrClient().getZkStateReader(),
+        false, true, 30);
+    AbstractDistribZkTestBase.waitForRecoveriesToFinish("testCollection2", cluster.getSolrClient().getZkStateReader(),
+        false, true, 30);
+  }
+
+  @Test
+  public void test() throws KeeperException, InterruptedException, IOException, SolrServerException {
+    ZkStateReader stateReader = cluster.getSolrClient().getZkStateReader();
+    stateReader.forceUpdateCollection(TEST_COLLECTION_1);
+    List<Replica> replicasOfCollection1 = stateReader.getClusterState().getCollection(TEST_COLLECTION_1).getReplicas();
+    List<Replica> replicasOfCollection2 = stateReader.getClusterState().getCollection(TEST_COLLECTION_2).getReplicas();
+    Replica replica = findLeaderReplicaWithDuplicatedName(replicasOfCollection1, replicasOfCollection2);
+    assertNotNull(replica);
+
+    SolrClient shardLeaderClient = new HttpSolrClient.Builder(replica.get("base_url").toString()).build();
+    try {
+      assertEquals(1L, getElectionNodes(TEST_COLLECTION_1, "shard1", stateReader.getZkClient()).size());
+      List<String> collection2Shard1Nodes = getElectionNodes(TEST_COLLECTION_2, "shard1", stateReader.getZkClient());
+      List<String> collection2Shard2Nodes = getElectionNodes(TEST_COLLECTION_2, "shard2", stateReader.getZkClient());
+      CoreAdminRequest.unloadCore(replica.getCoreName(), shardLeaderClient);
+      // Waiting for leader election being kicked off
+      long timeout = System.nanoTime() + TimeUnit.NANOSECONDS.convert(60, TimeUnit.SECONDS);
+      boolean found = false;
+      while (System.nanoTime() < timeout) {
+        try {
+          found = getElectionNodes(TEST_COLLECTION_1, "shard1", stateReader.getZkClient()).size() == 0;
+          break;
+        } catch (KeeperException.NoNodeException nne) {
+          // ignore
+        }
+      }
+      assertTrue(found);
+      // There are no leader election was kicked off on testCollection2
+      assertThat(collection2Shard1Nodes, CoreMatchers.is(getElectionNodes(TEST_COLLECTION_2, "shard1", stateReader.getZkClient())));
+      assertThat(collection2Shard2Nodes, CoreMatchers.is(getElectionNodes(TEST_COLLECTION_2, "shard2", stateReader.getZkClient())));
+    } finally {
+      shardLeaderClient.close();
+    }
+  }
+
+  private Replica findLeaderReplicaWithDuplicatedName(List<Replica> replicas1, List<Replica> replicas2) {
+    for (Replica replica1 : replicas1) {
+      if (!replica1.containsKey("leader")) continue;
+      for (Replica replica2 : replicas2) {
+        if (replica1.getName().equals(replica2.getName())
+            && replica1.get("base_url").equals(replica2.get("base_url"))
+            && replica2.containsKey("leader")) {
+          return replica1;
+        }
+      }
+    }
+    return null;
+  }
+
+  private List<String> getElectionNodes(String collection, String shard, SolrZkClient client) throws KeeperException, InterruptedException {
+    return client.getChildren("/collections/"+collection+"/leader_elect/"+shard+LeaderElector.ELECTION_NODE, null, true);
+  }
+}