recently, we integrated shiro with springboot and used redis as the session cache container for shiro. Most netizens on Baidu shiro configured the same cacheManager and sessionDAO, in SecurityManager and checked the source code with questions. We found that the storage of shiro"s session only needs to inherit the AbstractSessionDAO implementation, the abstract method in which redis is used to save session, so it is doubtful why we still need to implement CacheManager interface, and then SecurityManager configure a cacheManager, which is not superfluous. It"s not useful at all. I don"t know if I understand it correctly. Please let me know clearly. Thank you here!