@Override
  public List<ReplicationQueueId> listAllQueueIds(String peerId) throws ReplicationException {
    Scan scan = new Scan().setStartStopRowForPrefixScan(ReplicationQueueId.getScanPrefix(peerId))
      .addFamily(QUEUE_FAMILY).setFilter(new KeyOnlyFilter());
    List<ReplicationQueueId> queueIds = new ArrayList<>();
    try (Table table = conn.getTable(tableName)) {
      listAllQueueIds(table, scan, queueIds);
    } catch (IOException e) {
      throw new ReplicationException("failed to listAllQueueIds, peerId=" + peerId, e);
    }
    return queueIds;
  }
HBase table based replication queue storage.
hbase-replication/src/main/java/org/apache/hadoop/hbase/replication/TableReplicationQueueStorage.java