material:
1. The problem of session consistency in distributed systems
https://www.cnblogs.com/study-everyday/p/7853145.html
2. [Linux operation and maintenance - advanced cluster technology] 5 kinds of session processing strategies in cluster/distributed environment
https://blog.csdn.net/u010028869/article/details/50773174?ref=myread
3. About using Redis for distributed session management
https://zhuanlan.zhihu.com/p/25120947
4. Explain distributed session management in detail
https://zhuanlan.zhihu.com/p/28892514