I am trying to Implement real time notification system, the Approach that i am going to use is by opening a different socket using node's socket.io module, and then record each event of a user, afterwards send data to Mysql and use this data for notifications. So is it a better approach, any suggestions.

Personally I would go for redis+node. Main reason is to lower disk IO. Negative side might be possible data loss with redis (server reboot, service restart etc.). But that also can be configured in redis.