public String waitOnRegionServer(JVMClusterUtil.RegionServerThread rst) {
    boolean interrupted = false;
    while (rst.isAlive()) {
      try {
        LOG.info("Waiting on " + rst.getRegionServer().toString());
        rst.join();
      } catch (InterruptedException e) {
        LOG.error("Interrupted while waiting for {} to finish. Retrying join", rst.getName(), e);
        interrupted = true;
      }
    }
    regionThreads.remove(rst);
    if (interrupted) {
      Thread.currentThread().interrupt();
    }
    return rst.getName();
  }
Wait for the specified region server to stop. Removes this thread from list of running threads.
@return Name of region server that just went down.
hbase-server/src/main/java/org/apache/hadoop/hbase/LocalHBaseCluster.java