private List<AbstractHeartbeatSample> fromInterval(long[] interval, long timeElapsed) {
    long now = System.nanoTime();
    long begin = now - timeElapsed;
    List<AbstractHeartbeatSample> sample = new LinkedList<>();
    sample.add(new NodeHeartbeatSample(begin, NodeStatus.Running));
    for (int i = interval.length - 1; i >= 0; i--) {
      begin -= interval[i];
      sample.add(0, new NodeHeartbeatSample(begin, NodeStatus.Running));
    }
    return sample;
  }
If the Phi detector haven't received enough samples its behavior will fall back to Fix detector
iotdb-core/confignode/src/test/java/org/apache/iotdb/confignode/manager/load/cache/detector/DetectorTest.java