public static StreamSlowMonitor create(Configuration conf, String name) {
    return new StreamSlowMonitor(conf, name, new ExcludeDatanodeManager(conf));
  }
Configure for the check of large packet(which is configured by
{@link StreamSlowMonitor#DATANODE_PACKET_FLUSH_CHECK_SPEED_MIN_DATA_LENGTH_KEY}) flush speed.
e.g. If the configured slow packet process time is smaller than 10s, then here 20KB/s means
64KB should be processed in less than 3.2s.
hbase-asyncfs/src/main/java/org/apache/hadoop/hbase/io/asyncfs/monitor/StreamSlowMonitor.java