public void buildSyncLogChannel(Peer targetPeer, long initialSyncIndex, boolean startNow) {
    KillPoint.setKillPoint(DataNodeKillPoints.ORIGINAL_ADD_PEER_DONE);
    configuration.add(targetPeer);
    if (Objects.equals(targetPeer, thisNode)) {
      return;
    }
    logDispatcher.addLogDispatcherThread(targetPeer, initialSyncIndex, startNow);
    logger.info(
        "[IoTConsensus] Successfully build sync log channel to {} with initialSyncIndex {}. {}",
        targetPeer,
        initialSyncIndex,
        startNow ? "Sync log channel has started." : "Sync log channel maybe start later.");
  }
build SyncLog channel with safeIndex as the default initial sync index.
iotdb-core/consensus/src/main/java/org/apache/iotdb/consensus/iot/IoTConsensusServerImpl.java