/*
    *
    * 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.master;
  
  import static org.apache.hadoop.hbase.HConstants.DEFAULT_HBASE_RPC_TIMEOUT;
  import static org.apache.hadoop.hbase.HConstants.HBASE_RPC_TIMEOUT_KEY;
  import static org.junit.Assert.assertEquals;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.concurrent.TimeUnit;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.HRegionLocation;
  import org.apache.hadoop.hbase.ServerName;
  import org.apache.hadoop.hbase.ipc.HBaseRpcController;
  import org.apache.hadoop.hbase.ipc.RpcClient;
  import org.apache.hadoop.hbase.ipc.RpcClientFactory;
  import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
  import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos;
  import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
  import org.apache.hadoop.hbase.security.User;
  import org.apache.hadoop.hbase.testclassification.MasterTests;
  import org.apache.hadoop.hbase.testclassification.MediumTests;
  import org.apache.hadoop.hbase.util.JVMClusterUtil;
  import org.junit.AfterClass;
  import org.junit.BeforeClass;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.ClientMetaService;
  import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.GetClusterIdRequest;
  import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.GetClusterIdResponse;
  import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.GetMetaRegionLocationsRequest;
  import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.GetMetaRegionLocationsResponse;
  
  @Category({MediumTests.class, MasterTests.class})
  public class TestClientMetaServiceRPCs {
  
    // Total number of masters (active + stand by) for the purpose of this test.
    private static final int MASTER_COUNT = 3;
    private static final int RS_COUNT = 3;
    private static final HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
    private static Configuration conf;
    private static int rpcTimeout;
    private static RpcClient rpcClient;
  
    @BeforeClass
    public static void setUp() throws Exception {
      // Start the mini cluster with stand-by masters.
      TEST_UTIL.startMiniCluster(MASTER_COUNT, RS_COUNT);
      conf = TEST_UTIL.getConfiguration();
      rpcTimeout = (int) Math.min(Integer.MAX_VALUE, TimeUnit.MILLISECONDS.toNanos(
          conf.getLong(HBASE_RPC_TIMEOUT_KEY, DEFAULT_HBASE_RPC_TIMEOUT)));
      rpcClient = RpcClientFactory.createClient(conf,
          TEST_UTIL.getMiniHBaseCluster().getMaster().getClusterId());
    }
  
    @AfterClass
    public static void tearDown() throws Exception {
      if (rpcClient != null) {
        rpcClient.close();
      }
      TEST_UTIL.shutdownMiniCluster();
    }
  
    private static ClientMetaService.BlockingInterface getMasterStub(ServerName server)
        throws IOException {
      return ClientMetaService.newBlockingStub(
          rpcClient.createBlockingRpcChannel(server, User.getCurrent(), rpcTimeout));
    }
  
    private static HBaseRpcController getRpcController() {
      return RpcControllerFactory.instantiate(conf).newController();
    }
  
    /**
     * Verifies the cluster ID from all running masters.
     */
    @Test public void TestClusterID() throws Exception {
      HBaseRpcController rpcController = getRpcController();
      String clusterID = TEST_UTIL.getMiniHBaseCluster().getMaster().getClusterId();
      int rpcCount = 0;
     for (JVMClusterUtil.MasterThread masterThread:
         TEST_UTIL.getMiniHBaseCluster().getMasterThreads()) {
       ClientMetaService.BlockingInterface stub =
           getMasterStub(masterThread.getMaster().getServerName());
       GetClusterIdResponse resp =
           stub.getClusterId(rpcController, GetClusterIdRequest.getDefaultInstance());
       assertEquals(clusterID, resp.getClusterId());
       rpcCount++;
     }
     assertEquals(MASTER_COUNT, rpcCount);
   }
 
   /**
    * Verifies that the meta region locations RPC returns consistent results across all masters.
    */
   @Test public void TestMetaLocations() throws Exception {
     HBaseRpcController rpcController = getRpcController();
     List<HRegionLocation> metaLocations = TEST_UTIL.getMiniHBaseCluster().getMaster()
         .getMetaRegionLocationCache().getMetaRegionLocations();
     Collections.sort(metaLocations);
     int rpcCount = 0;
     for (JVMClusterUtil.MasterThread masterThread:
       TEST_UTIL.getMiniHBaseCluster().getMasterThreads()) {
       ClientMetaService.BlockingInterface stub =
           getMasterStub(masterThread.getMaster().getServerName());
       GetMetaRegionLocationsResponse resp = stub.getMetaRegionLocations(
           rpcController, GetMetaRegionLocationsRequest.getDefaultInstance());
       List<HRegionLocation> result = new ArrayList<>();
       for (HBaseProtos.RegionLocation location: resp.getMetaLocationsList()) {
         result.add(ProtobufUtil.toRegionLocation(location));
       }
       Collections.sort(result);
       assertEquals(metaLocations, result);
       rpcCount++;
     }
     assertEquals(MASTER_COUNT, rpcCount);
   }
 }