private Map<String, Integer> getFragmentationInfo(HMaster master, Configuration conf)
    throws IOException {
    boolean showFragmentation = conf.getBoolean("hbase.master.ui.fragmentation.enabled", false);
    if (showFragmentation) {
      return FSUtils.getTableFragmentation(master);
    } else {
      return null;
    }
  }
The servlet responsible for rendering the index page of the master.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/http/MasterStatusServlet.java