Check if AssignmentManager does not use drained region servers.

TestDrainedServer.java

  @Test
  public void testAssignmentManagementDoesNotUseDrainedServers() 
      throws KeeperException, Exception {

    HMaster master = TEST_UTIL.getHBaseCluster().getMaster();
    
    waitForAllRegionsOnline();
    
    ServerManager serverManager = master.getServerManager();
    AssignmentManager assignmentManager = master.getAssignmentManager();
    
    HRegionServer drainedRS0 = TEST_UTIL.getHBaseCluster().getRegionServer(0);
    HRegionServer drainedRS3 = TEST_UTIL.getHBaseCluster().getRegionServer(3);
        
    setDrainingServer(drainedRS0);
    setDrainingServer(drainedRS3);
        
    waitSyncMasterAndAssignmentManagementServerList();
    

    List<HRegionInfo> regionRS0List = ProtobufUtil.getOnlineRegions(drainedRS0);
    List<HRegionInfo> regionRS3List = ProtobufUtil.getOnlineRegions(drainedRS3);
    
    assignmentManager.assign(regionRS0List);
    assignmentManager.assign(regionRS3List);
    
    assertFalse(serverManager.createDestinationServersList().contains(drainedRS0));
    assertFalse(serverManager.createDestinationServersList().contains(drainedRS0));
    
    Map<HRegionInfo, ServerName> regionAssignmentList = 
        assignmentManager.getRegionStates().getRegionAssignments();
    
    assertFalse(regionAssignmentList.containsValue(drainedRS0.getServerName()));
    assertFalse(regionAssignmentList.containsValue(drainedRS3.getServerName()));
    
  }
  

  /**
   * Synchronize server list on Master and Assignment 
   * Management, verifying if server manager and 
   * assignment region list contains drained server, 
   * if both not contains drained servers, is synchronized.
   * @throws InterruptedException
   */
  private static void waitSyncMasterAndAssignmentManagementServerList() throws InterruptedException {
    HMaster master = TEST_UTIL.getHBaseCluster().getMaster();
    ServerManager serverManager = master.getServerManager();
    AssignmentManager assignmentManager = master.getAssignmentManager();
    List<ServerName> drainedServerList = serverManager.getDrainingServersList();
    Map<HRegionInfo, ServerName> assignmentRegionList = 
        assignmentManager.getRegionStates().getRegionAssignments();
    
    if (!drainedServerList.isEmpty()) {
      for (ServerName drainedServer : drainedServerList) {
        while (serverManager.createDestinationServersList().contains(drainedServer) ||
            assignmentRegionList.containsValue(drainedServer)) {
          Thread.sleep(1);
        }
      }
    }
    
  }