flink运行架构:https://blog.csdn.net/Luomingkui1109/article/details/95232428
一文读懂flink架构和特性:https://cloud.tencent.com/developer/article/1523028
flink常用算子:https://blog.csdn.net/chybin500/article/details/87260869
https://gitbook.cn/books/5de5ea4c984ce511296b746a/index.html