@BeforeClass
  public static void setUp() throws Exception {
    UTIL.getConfiguration().setInt(ServerManager.WAIT_ON_REGIONSERVERS_MINTOSTART, 1);
    UTIL.startMiniCluster(3);
    UTIL.createTable(TABLE_NAME, CF);
    UTIL.getAdmin().balancerSwitch(false, true);
    HRegionServer srcRs = UTIL.getRSForFirstRegionInTable(TABLE_NAME);
    if (!srcRs.getRegions(TableName.META_TABLE_NAME).isEmpty()) {
      RegionInfo metaRegion = srcRs.getRegions(TableName.META_TABLE_NAME).get(0).getRegionInfo();
      HRegionServer dstRs = UTIL.getOtherRegionServer(srcRs);
      UTIL.getAdmin().move(metaRegion.getEncodedNameAsBytes(), dstRs.getServerName());
      UTIL.waitFor(30000, () -> !dstRs.getRegions(TableName.META_TABLE_NAME).isEmpty());
    }
  }
Confirm that we will do backoff when retrying on closing a region, to avoid consuming all the
CPUs.
hbase-server/src/test/java/org/apache/hadoop/hbase/master/assignment/TestCloseRegionWhileRSCrash.java