使用broadcast state实现动态配置更新，即双流：一个数据流，一个配置流
1 | https://flink.apache.org/2019/06/26/broadcast-state.html |
可以参考官方文档
1 | https://ci.apache.org/projects/flink/flink-docs-release-1.13/docs/dev/datastream/fault-tolerance/broadcast_state/ |
例子：Flink使用Broadcast State实现流处理配置实时更新
