@Override
    public void doAnAction() throws Exception {
      // Pick a random row to write into
      byte[] targetRow = targetRows[ThreadLocalRandom.current().nextInt(targetRows.length)];
      Put p = new Put(targetRow);
      Bytes.random(data);
      for (byte[] family : targetFamilies) {
        for (int i = 0; i < NUM_COLS_TO_CHECK; i++) {
          byte qualifier[] = Bytes.toBytes("col" + i);
          p.addColumn(family, qualifier, data);
        }
      }
      table.put(p);
      numWritten.getAndIncrement();
    }
Thread that does random full-row writes into a table.
hbase-server/src/test/java/org/apache/hadoop/hbase/AcidGuaranteesTestTool.java