001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.master;
019
020import static org.junit.jupiter.api.Assertions.assertFalse;
021import static org.junit.jupiter.api.Assertions.assertTrue;
022
023import java.io.IOException;
024import java.util.List;
025import org.apache.hadoop.hbase.ClusterMetrics;
026import org.apache.hadoop.hbase.HBaseTestingUtil;
027import org.apache.hadoop.hbase.MasterNotRunningException;
028import org.apache.hadoop.hbase.SingleProcessHBaseCluster;
029import org.apache.hadoop.hbase.StartTestingClusterOption;
030import org.apache.hadoop.hbase.testclassification.LargeTests;
031import org.apache.hadoop.hbase.testclassification.MasterTests;
032import org.apache.hadoop.hbase.util.JVMClusterUtil;
033import org.junit.jupiter.api.Tag;
034import org.junit.jupiter.api.Test;
035
036@Tag(MasterTests.TAG)
037@Tag(LargeTests.TAG)
038public class TestMasterFailoverBalancerPersistence {
039
040  /**
041   * Test that if the master fails, the load balancer maintains its state (running or not) when the
042   * next master takes over
043   */
044  @Test
045  public void testMasterFailoverBalancerPersistence() throws Exception {
046    // Start the cluster
047    HBaseTestingUtil TEST_UTIL = new HBaseTestingUtil();
048
049    StartTestingClusterOption option = StartTestingClusterOption.builder().numMasters(3).build();
050    TEST_UTIL.startMiniCluster(option);
051    SingleProcessHBaseCluster cluster = TEST_UTIL.getHBaseCluster();
052
053    assertTrue(cluster.waitForActiveAndReadyMaster());
054    HMaster active = cluster.getMaster();
055    // check that the balancer is on by default for the active master
056    ClusterMetrics clusterStatus = active.getClusterMetrics();
057    assertTrue(clusterStatus.getBalancerOn());
058
059    active = killActiveAndWaitForNewActive(cluster);
060
061    // ensure the load balancer is still running on new master
062    clusterStatus = active.getClusterMetrics();
063    assertTrue(clusterStatus.getBalancerOn());
064
065    // turn off the load balancer
066    active.balanceSwitch(false);
067
068    // once more, kill active master and wait for new active master to show up
069    active = killActiveAndWaitForNewActive(cluster);
070
071    // ensure the load balancer is not running on the new master
072    clusterStatus = active.getClusterMetrics();
073    assertFalse(clusterStatus.getBalancerOn());
074
075    // Stop the cluster
076    TEST_UTIL.shutdownMiniCluster();
077  }
078
079  /**
080   * Kill the master and wait for a new active master to show up
081   * @return the new active master
082   */
083  private HMaster killActiveAndWaitForNewActive(SingleProcessHBaseCluster cluster)
084    throws InterruptedException, IOException {
085    int activeIndex = getActiveMasterIndex(cluster);
086    HMaster active = cluster.getMaster();
087    cluster.stopMaster(activeIndex);
088    cluster.waitOnMaster(activeIndex);
089    assertTrue(cluster.waitForActiveAndReadyMaster());
090    // double check this is actually a new master
091    HMaster newActive = cluster.getMaster();
092    assertFalse(active == newActive);
093    return newActive;
094  }
095
096  /**
097   * return the index of the active master in the cluster
098   * @throws org.apache.hadoop.hbase.MasterNotRunningException if no active master found
099   */
100  private int getActiveMasterIndex(SingleProcessHBaseCluster cluster)
101    throws MasterNotRunningException {
102    // get all the master threads
103    List<JVMClusterUtil.MasterThread> masterThreads = cluster.getMasterThreads();
104
105    for (int i = 0; i < masterThreads.size(); i++) {
106      if (masterThreads.get(i).getMaster().isActiveMaster()) {
107        return i;
108      }
109    }
110    throw new MasterNotRunningException();
111  }
112
113}