public JVMClusterUtil.RegionServerThread suspendRegionServer(int serverNumber) {
    JVMClusterUtil.RegionServerThread server = hbaseCluster.getRegionServers().get(serverNumber);
    LOG.info("Suspending {}", server.toString());
    server.suspend();
    return server;
  }
Suspend the specified region server
@param serverNumber Used as index into a list.
hbase-server/src/test/java/org/apache/hadoop/hbase/SingleProcessHBaseCluster.java