How do you assess database system stability?

You are the owner of a production database (or an entire database platform) that a number of different services rely on. A stakeholder asks you a deceptively simple question: is this system stable right now, and how would you know? Explain how you would go about answering that, covering at least the following areas: Which signals of reliability and performance you would collect, and how you would shape them into service-level indicators and service-level objectives. How…