@Override
            public void produce(
                String threadName,
                ThreadGroup workerGroups,
                IndexedBlockingQueue<DriverTask> queue,
                ThreadProducer producer) {
              DriverTaskThread newThread =
                  new DriverTaskThread(threadName, workerGroups, readyQueue, scheduler, this);
              threads.set(index, newThread);
              newThread.start();
            }
The manager of fragment instances scheduling.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/schedule/DriverScheduler.java