@Test
  public void testVerifyRepJob() throws Exception {
    // Populate the tables, at the same time it guarantees that the tables are
    // identical since it does the check
    runSmallBatchTest();

    String[] args = new String[] { PEER_ID, tableName.getNameAsString() };
    runVerifyReplication(args, NB_ROWS_IN_BATCH, 0);

    Scan scan = new Scan();
    ResultScanner rs = htable2.getScanner(scan);
    Put put = null;
    for (Result result : rs) {
      put = new Put(result.getRow());
      Cell firstVal = result.rawCells()[0];
      put.addColumn(CellUtil.cloneFamily(firstVal), CellUtil.cloneQualifier(firstVal),
        Bytes.toBytes("diff data"));
      htable2.put(put);
    }
    Delete delete = new Delete(put.getRow());
    htable2.delete(delete);
    runVerifyReplication(args, 0, NB_ROWS_IN_BATCH);
  }
Do a small loading into a table, make sure the data is really the same, then run the
VerifyReplication job to check the results. Do a second comparison where all the cells are
different.
hbase-mapreduce/src/test/java/org/apache/hadoop/hbase/replication/VerifyReplicationTestBase.java