public void rebootTimedService() throws ShutdownException {
    LOGGER.info("Start rebooting all timed service.");

    // exclude ttl check thread
    stopTimedServiceAndThrow(seqMemtableTimedFlushCheckThread, "SeqMemtableTimedFlushCheckThread");
    stopTimedServiceAndThrow(
        unseqMemtableTimedFlushCheckThread, "UnseqMemtableTimedFlushCheckThread");

    LOGGER.info("Stop all timed service successfully, and now restart them.");

    startTimedService();

    LOGGER.info("Reboot all timed service successfully");
  }
reboot timed flush sequence/unsequence memtable thread
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/storageengine/StorageEngine.java