This post is part 2 of a 3-part series on MySQL monitoring. It explains how to collect metrics from MySQL using two approaches: querying internal server status variables and the performance schema and sys schema. The performance schema stores performance metrics about individual SQL statements, while the sys schema provides easily interpretable tables for inspecting performance data. The post also discusses how to use a GUI, such as MySQL Workbench, to view performance metrics and a full-featured monitoring tool, like Datadog, to implement ongoing monitoring of a production MySQL database.