@Test
  public void testSeqIdsFromReplay() throws IOException {
    // test the case where seqId's coming from replayed WALEdits are made persisted with their
    // original seqIds and they are made visible through mvcc read point upon replay
    String method = name.getMethodName();
    byte[] tableName = Bytes.toBytes(method);
    byte[] family = Bytes.toBytes("family");

    HRegion region = initHRegion(tableName, family);
    try {
      // replay an entry that is bigger than current read point
      long readPoint = region.getMVCC().getReadPoint();
      long origSeqId = readPoint + 100;

      Put put = new Put(row).addColumn(family, row, row);
      put.setDurability(Durability.SKIP_WAL); // we replay with skip wal
      replay(region, put, origSeqId);

      // read point should have advanced to this seqId
      assertGet(region, family, row);

      // region seqId should have advanced at least to this seqId
      assertEquals(origSeqId, region.getReadPoint(null));

      // replay an entry that is smaller than current read point
      // caution: adding an entry below current read point might cause partial dirty reads. Normal
      // replay does not allow reads while replay is going on.
      put = new Put(row2).addColumn(family, row2, row2);
      put.setDurability(Durability.SKIP_WAL);
      replay(region, put, origSeqId - 50);

      assertGet(region, family, row2);
    } finally {
      region.close();
    }
  }
Tests whether edits coming in for replay are skipped which have smaller seq id than the seqId
of the last replayed region open event.
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestHRegionReplayEvents.java