The Art of Monitoring

13 Monitoring Tornado: Data tier

Our last tier, the Data tier, is made up of two servers, tornado-db running MySQL and tornado-redis running Redis. For Tornado’s Data tier, what do we care about? Let’s break down our concerns:

• That MySQL and Redis are running on their respective hosts.
• 99th-percentile latency adding items to the Tornado DB is three milliseconds or less.
• That maximum MySQL connections don’t exceed 80% of the available connections.
• That we can measure the rate of aborted connections to MySQL.
• That we are generating application metrics from data inside our MySQL database.
• That we can measure key queries to ensure they are performing within expectations.

We’ll start with configuring the monitoring for each component and the underlying ...