https://docs.aws.amazon.com/zh_cn/emr/latest/ManagementGuide/emr-what-is-emr.html
https://docs.aws.amazon.com/zh_cn/emr/latest/ReleaseGuide/emr-release-3x.html
https://blog.csdn.net/Agony__X/article/details/78707927
原文：https://www.cnblogs.com/575dsj/p/9235744.html