private ColumnFamilyDescriptor randomPickOneColumnFamily(ColumnFamilyDescriptor[] cfs) {
      int size = cfs.length;
      return cfs[ThreadLocalRandom.current().nextInt(size)];

    }
Run a single Region Task and then exit. For each column family of the Region, get one row and
output latency or failure.
hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java