I want to know what is the Exaxt Database for Web Analytics, can some help me?

I am currently using MongoDB, and familiar working with Web analytics similar to [Google Analytics].
I am Facing the Problem While using MongoDB
Reading and Writting is Performed almost in a Same time. After Some Point writting becomes slow. So, I am looking for the Exact Database, which Suits the following Requirements:
It should be Open Source
Time Based Aggregation
Real-Time Data Processsing.
I am fetching the data using Node JS and Saving with using Java.


I’m not sure, this is the correct forum for this. But I would prefer mysql or MariaDB.