Logstash performance

We are trying to deploy logstash in production.

So I need a detailed answer for these questions:

-Logstash extracts data from database using SQL. How exactly logstash get notified about new data?
-Is there a way to configure how logstash search new data?
We cannot rely on this kind of abstraction (even if it maybe optimum)

-is there any official performance reports that I can check?
We are going to make our personal tests, but it’s still good to have a first impression.



And no, we don't provide any sort of performance metrics around LS sorry.