应用服务器做缓存理解

 2、4、2 、3数据库做缓存：https://www.cnblogs.com/duanxz/p/3740595.html和https://blog.youkuaiyun.com/sanyaoxu_2/article/details/79472465

和https://blog.youkuaiyun.com/zeb_perfect/article/details/54135506和https://blog.youkuaiyun.com/cainiao_user/article/details/78301563

主从复制/读写分离/分库分表//缓存：https://mp.weixin.qq.com/s/CY4jntpM7VNkBrz1FKRsOw

2、4、2 、4 mybatis做缓存：https://blog.youkuaiyun.com/zmx729618/article/details/77991916和https://blog.youkuaiyun.com/hupanfeng/article/details/16950161   和https://www.jianshu.com/p/5ff874fa696f