public String abortRegionServer(int serverNumber) {
    HRegionServer server = getRegionServer(serverNumber);
    LOG.info("Aborting " + server.toString());
    server.abort("Aborting for tests", new Exception("Trace info"));
    return server.toString();
  }
Cause a region server to exit doing basic clean up only on its way out.
@param serverNumber Used as index into a list.
hbase-server/src/test/java/org/apache/hadoop/hbase/SingleProcessHBaseCluster.java