As a DBA, you're expected to know what's happening inside your databases at all times. But here's the reality — most monitoring setups are either too generic (CPU is high!) or too custom (someone's 3-year-old Grafana dashboard nobody understands). What if there was a tool built specifically for database engineers — one that understands query performance, replication lag, vacuum bloat, and connection saturation right out of the box? That tool is Percona Monitoring and Management (PMM) . In this post, I'll walk you through everything you need to know about PMM 3 — what it is, how it works internally, how to install it, what features it brings, and which databases it supports. Let's get into it. What is PMM? PMM (Percona Monitoring and Management) is a 100% free, open-source database observability and monitoring platform built by Percona. It is NOT a generic infrastructure monitoring tool like Nagios or Zabbix. PMM was purpose-built for DBAs who need to answer qu...