hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestMasterRegistry.java

/*
 * 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.hadoop.hbase.client;

import static org.apache.hadoop.hbase.HConstants.META_REPLICAS_NUM;
import static org.junit.Assert.assertEquals;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.HBaseClassTestRule;
import org.apache.hadoop.hbase.HBaseTestingUtility;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HRegionLocation;
import org.apache.hadoop.hbase.ServerName;
import org.apache.hadoop.hbase.StartMiniClusterOption;
import org.apache.hadoop.hbase.master.HMaster;
import org.apache.hadoop.hbase.testclassification.ClientTests;
import org.apache.hadoop.hbase.testclassification.MediumTests;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.ClassRule;
import org.junit.Test;
import org.junit.experimental.categories.Category;

@Category({ MediumTests.class, ClientTests.class })
public class TestMasterRegistry {

  @ClassRule
  public static final HBaseClassTestRule CLASS_RULE =
      HBaseClassTestRule.forClass(TestMasterRegistry.class);
  private static final HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();

  @BeforeClass
  public static void setUp() throws Exception {
    TEST_UTIL.getConfiguration().setInt(META_REPLICAS_NUM, 3);
    StartMiniClusterOption.Builder builder = StartMiniClusterOption.builder();
    builder.numMasters(3).numRegionServers(3);
    TEST_UTIL.startMiniCluster(builder.build());
  }

  @AfterClass
  public static void tearDown() throws Exception {
    TEST_UTIL.shutdownMiniCluster();
  }

  /**
   * Generates a string of dummy master addresses in host:port format. Every other hostname won't
   * have a port number.
   */
  private static String generateDummyMastersList(int size) {
    List<String> masters = new ArrayList<>();
    for (int i = 0; i < size; i++) {
      masters.add(" localhost" + (i % 2 == 0 ? ":" + (1000 + i) : ""));
    }
    return String.join(",", masters);
  }

  /**
   * Makes sure the master registry parses the master end points in the configuration correctly.
   */
  @Test
  public void testMasterAddressParsing() throws IOException {
    Configuration conf = new Configuration(TEST_UTIL.getConfiguration());
    int numMasters = 10;
    conf.set(HConstants.MASTER_ADDRS_KEY, generateDummyMastersList(numMasters));
    try (MasterRegistry registry = new MasterRegistry(conf)) {
      List<ServerName> parsedMasters = new ArrayList<>(registry.getParsedMasterServers());
      // Half of them would be without a port, duplicates are removed.
      assertEquals(numMasters / 2 + 1, parsedMasters.size());
      // Sort in the increasing order of port numbers.
      Collections.sort(parsedMasters, Comparator.comparingInt(ServerName::getPort));
      for (int i = 0; i < parsedMasters.size(); i++) {
        ServerName sn = parsedMasters.get(i);
        assertEquals("localhost", sn.getHostname());
        if (i == parsedMasters.size() - 1) {
          // Last entry should be the one with default port.
          assertEquals(HConstants.DEFAULT_MASTER_PORT, sn.getPort());
        } else {
          assertEquals(1000 + (2 * i), sn.getPort());
        }
      }
    }
  }

  @Test
  public void testRegistryRPCs() throws Exception {
    Configuration conf = new Configuration(TEST_UTIL.getConfiguration());
    HMaster activeMaster = TEST_UTIL.getHBaseCluster().getMaster();
    final int size =
      activeMaster.getMetaRegionLocationCache().getMetaRegionLocations().get().size();
    for (int numHedgedReqs = 1; numHedgedReqs <= size; numHedgedReqs++) {
      conf.setInt(MasterRegistry.MASTER_REGISTRY_HEDGED_REQS_FANOUT_KEY, numHedgedReqs);
      try (MasterRegistry registry = new MasterRegistry(conf)) {
        // Add wait on all replicas being assigned before proceeding w/ test. Failed on occasion
        // because not all replicas had made it up before test started.
        RegionReplicaTestHelper.waitUntilAllMetaReplicasAreReady(TEST_UTIL, registry);
        assertEquals(registry.getClusterId().get(), activeMaster.getClusterId());
        assertEquals(registry.getActiveMaster().get(), activeMaster.getServerName());
        List<HRegionLocation> metaLocations =
          Arrays.asList(registry.getMetaRegionLocations().get().getRegionLocations());
        List<HRegionLocation> actualMetaLocations =
          activeMaster.getMetaRegionLocationCache().getMetaRegionLocations().get();
        Collections.sort(metaLocations);
        Collections.sort(actualMetaLocations);
        assertEquals(actualMetaLocations, metaLocations);
      }
    }
  }
}