How to use replay module

Hello, is it possible to add more information in your documentation?
Have a lot of questions like
How to interpret the content of file db_name_host:port?
How to save result of replay in a file? And what the result of replay?
Here is what I have
![screenshot-1](https://cloud.githubusercontent.com/assets/3337051/9006891/d44a42c8-3794-11e5-88dd-7efd93fb9ebf.png)

Am I using replay in a wrong way?
