Description of the problem:
the same ip request the same url ------------------------- "nginx --------------- ---------> nginx load balancer to a different server
If you logged in to save on server A, the next time a page is requested on the server B, server B can not get logged on the server will think A user is not logged in and do abnormal operation (ie verification session, but A saved in the user's session on the server s1), it will alert the user to log in, so jump to the login page, then this is a drawback for load balancing request with the state's.
Solution:
https://www.cnblogs.com/zengguowang/p/8261695.html
