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.balancer;
019
020import static org.junit.Assert.assertEquals;
021import static org.junit.Assert.assertFalse;
022import static org.junit.Assert.assertTrue;
023
024import java.util.ArrayList;
025import java.util.Collections;
026import java.util.HashMap;
027import java.util.HashSet;
028import java.util.Iterator;
029import java.util.List;
030import java.util.Map;
031import java.util.Set;
032import org.apache.commons.lang3.StringUtils;
033import org.apache.hadoop.hbase.HBaseClassTestRule;
034import org.apache.hadoop.hbase.HConstants;
035import org.apache.hadoop.hbase.ServerName;
036import org.apache.hadoop.hbase.TableName;
037import org.apache.hadoop.hbase.client.RegionInfo;
038import org.apache.hadoop.hbase.master.LoadBalancer;
039import org.apache.hadoop.hbase.master.RegionPlan;
040import org.apache.hadoop.hbase.net.Address;
041import org.apache.hadoop.hbase.rsgroup.RSGroupBasedLoadBalancer;
042import org.apache.hadoop.hbase.rsgroup.RSGroupInfo;
043import org.apache.hadoop.hbase.testclassification.LargeTests;
044import org.apache.hadoop.net.DNSToSwitchMapping;
045import org.junit.BeforeClass;
046import org.junit.ClassRule;
047import org.junit.Test;
048import org.junit.experimental.categories.Category;
049import org.slf4j.Logger;
050import org.slf4j.LoggerFactory;
051
052import org.apache.hbase.thirdparty.com.google.common.collect.ArrayListMultimap;
053
054/**
055 * Test RSGroupBasedLoadBalancer with SimpleLoadBalancer as internal balancer
056 */
057@Category(LargeTests.class)
058public class TestRSGroupBasedLoadBalancer extends RSGroupableBalancerTestBase {
059  @ClassRule
060  public static final HBaseClassTestRule CLASS_RULE =
061    HBaseClassTestRule.forClass(TestRSGroupBasedLoadBalancer.class);
062  private static final Logger LOG = LoggerFactory.getLogger(TestRSGroupBasedLoadBalancer.class);
063  private static RSGroupBasedLoadBalancer loadBalancer;
064
065  @BeforeClass
066  public static void beforeAllTests() throws Exception {
067    servers = generateServers(7);
068    groupMap = constructGroupInfo(servers, groups);
069    tableDescs = constructTableDesc(true);
070    conf.set("hbase.regions.slop", "0");
071    conf.set("hbase.rsgroup.grouploadbalancer.class", SimpleLoadBalancer.class.getCanonicalName());
072    conf.setClass("hbase.util.ip.to.rack.determiner", MockMapping.class, DNSToSwitchMapping.class);
073    loadBalancer = new RSGroupBasedLoadBalancer();
074    loadBalancer.setMasterServices(getMockedMaster());
075    loadBalancer.initialize();
076  }
077
078  /**
079   * Test the load balancing algorithm. Invariant is that all servers of the group should be hosting
080   * either floor(average) or ceiling(average)
081   */
082  @Test
083  public void testBalanceCluster() throws Exception {
084    // Test with/without per table balancer.
085    boolean[] perTableBalancerConfigs = { true, false };
086    for (boolean isByTable : perTableBalancerConfigs) {
087      conf.setBoolean(HConstants.HBASE_MASTER_LOADBALANCE_BYTABLE, isByTable);
088      loadBalancer.onConfigurationChange(conf);
089      Map<ServerName, List<RegionInfo>> servers = mockClusterServers();
090      ArrayListMultimap<String, ServerAndLoad> list = convertToGroupBasedMap(servers);
091      LOG.info("Mock Cluster :  " + printStats(list));
092      Map<TableName, Map<ServerName, List<RegionInfo>>> LoadOfAllTable =
093        (Map) mockClusterServersWithTables(servers);
094      List<RegionPlan> plans = loadBalancer.balanceCluster(LoadOfAllTable);
095      ArrayListMultimap<String, ServerAndLoad> balancedCluster = reconcile(list, plans);
096      LOG.info("Mock Balance : " + printStats(balancedCluster));
097      assertClusterAsBalanced(balancedCluster);
098    }
099  }
100
101  /**
102   * Tests the bulk assignment used during cluster startup.
103   * <p/>
104   * Round-robin. Should yield a balanced cluster so same invariant as the load balancer holds, all
105   * servers holding either floor(avg) or ceiling(avg).
106   */
107  @Test
108  public void testBulkAssignment() throws Exception {
109    List<RegionInfo> regions = randomRegions(25);
110    Map<ServerName, List<RegionInfo>> assignments =
111      loadBalancer.roundRobinAssignment(regions, servers);
112    // test empty region/servers scenario
113    // this should not throw an NPE
114    loadBalancer.roundRobinAssignment(regions, Collections.emptyList());
115    // test regular scenario
116    assertTrue(assignments.keySet().size() == servers.size());
117    for (ServerName sn : assignments.keySet()) {
118      List<RegionInfo> regionAssigned = assignments.get(sn);
119      for (RegionInfo region : regionAssigned) {
120        TableName tableName = region.getTable();
121        String groupName =
122          tableDescs.get(tableName).getRegionServerGroup().orElse(RSGroupInfo.DEFAULT_GROUP);
123        assertTrue(StringUtils.isNotEmpty(groupName));
124        RSGroupInfo gInfo = getMockedGroupInfoManager().getRSGroup(groupName);
125        assertTrue("Region is not correctly assigned to group servers.",
126          gInfo.containsServer(sn.getAddress()));
127      }
128    }
129    ArrayListMultimap<String, ServerAndLoad> loadMap = convertToGroupBasedMap(assignments);
130    assertClusterAsBalanced(loadMap);
131  }
132
133  /**
134   * Test the cluster startup bulk assignment which attempts to retain assignment info.
135   */
136  @Test
137  public void testRetainAssignment() throws Exception {
138    // Test simple case where all same servers are there
139    Map<ServerName, List<RegionInfo>> currentAssignments = mockClusterServers();
140    Map<RegionInfo, ServerName> inputForTest = new HashMap<>();
141    for (ServerName sn : currentAssignments.keySet()) {
142      for (RegionInfo region : currentAssignments.get(sn)) {
143        inputForTest.put(region, sn);
144      }
145    }
146    // verify region->null server assignment is handled
147    inputForTest.put(randomRegions(1).get(0), null);
148    Map<ServerName, List<RegionInfo>> newAssignment =
149      loadBalancer.retainAssignment(inputForTest, servers);
150    assertRetainedAssignment(inputForTest, servers, newAssignment);
151  }
152
153  /**
154   * Test BOGUS_SERVER_NAME among groups do not overwrite each other.
155   */
156  @Test
157  public void testRoundRobinAssignment() throws Exception {
158    List<ServerName> onlineServers = new ArrayList<ServerName>(servers.size());
159    onlineServers.addAll(servers);
160    List<RegionInfo> regions = randomRegions(25);
161    int bogusRegion = 0;
162    for (RegionInfo region : regions) {
163      String group =
164        tableDescs.get(region.getTable()).getRegionServerGroup().orElse(RSGroupInfo.DEFAULT_GROUP);
165      if ("dg3".equals(group) || "dg4".equals(group)) {
166        bogusRegion++;
167      }
168    }
169    Set<Address> offlineServers = new HashSet<Address>();
170    offlineServers.addAll(groupMap.get("dg3").getServers());
171    offlineServers.addAll(groupMap.get("dg4").getServers());
172    for (Iterator<ServerName> it = onlineServers.iterator(); it.hasNext();) {
173      ServerName server = it.next();
174      Address address = server.getAddress();
175      if (offlineServers.contains(address)) {
176        it.remove();
177      }
178    }
179    Map<ServerName, List<RegionInfo>> assignments =
180      loadBalancer.roundRobinAssignment(regions, onlineServers);
181    assertEquals(bogusRegion, assignments.get(LoadBalancer.BOGUS_SERVER_NAME).size());
182  }
183
184  @Test
185  public void testOnConfigurationChange() {
186    // fallbackEnabled default is false
187    assertFalse(loadBalancer.isFallbackEnabled());
188
189    // change FALLBACK_GROUP_ENABLE_KEY from false to true
190    conf.setBoolean(RSGroupBasedLoadBalancer.FALLBACK_GROUP_ENABLE_KEY, true);
191    loadBalancer.onConfigurationChange(conf);
192    assertTrue(loadBalancer.isFallbackEnabled());
193
194    // restore
195    conf.setBoolean(RSGroupBasedLoadBalancer.FALLBACK_GROUP_ENABLE_KEY, false);
196    loadBalancer.onConfigurationChange(conf);
197    assertFalse(loadBalancer.isFallbackEnabled());
198  }
199}