Any processing you would like to do on session variables.
可以对会话变量做任何你想要的处理。
This causes degraded performance as increasing amounts of time and bandwidth are absorbed in maintaining consistency of session backups across the cluster rather than processing user requests.
这会造成性能的下降：越来越多的时间和带宽花在了在集群中维护会话备份的一致性，而不是用来处理用户请求。
Typical examples include logging data about the request or response, processing security protocols, managing session attributes, and more.
典型的例子包括记录关于请求和响应的数据、处理安全协议、管理会话属性，等等。
应用推荐