private static long getSeqNumDuringOpen(final Result r, final int replicaId) {
    Cell cell = r.getColumnLatestCell(HConstants.CATALOG_FAMILY, getSeqNumColumn(replicaId));
    if (cell == null || cell.getValueLength() == 0) {
      return HConstants.NO_SEQNUM;
    }
    return Bytes.toLong(cell.getValueArray(), cell.getValueOffset(), cell.getValueLength());
  }
The latest seqnum that the server writing to meta observed when opening the region. E.g. the
seqNum when the result of {@link getServerName} was written.
@param r Result to pull the seqNum from
@return SeqNum, or HConstants.NO_SEQNUM if there's no value written.
hbase-client/src/main/java/org/apache/hadoop/hbase/CatalogFamilyFormat.java