Key Observability Terms

Understanding observability starts with a few essential terms. Here are the key concepts you will encounter and use as you build reliable systems:

• Metrics: numerical values collected over time that show how a system is performing, such as CPU usage, memory consumption, or request rates;
• Logs: recorded messages or data entries produced by applications and systems, often used for troubleshooting or auditing what happened at a specific time;
• Traces: records of the path a request takes as it moves through different services or components, helping you see where delays or errors occur;
• Alerts: automatic notifications triggered when metrics or logs meet specific conditions, so you know right away when something needs attention;
• Monitoring: the ongoing process of collecting, analyzing, and reviewing metrics and logs to ensure systems are healthy and performing as expected;
• Dashboards: visual displays that organize and present metrics, logs, and alerts in one place, making it easy to spot trends and issues.

These terms form the foundation of observability. Knowing what they mean and how they work together will help you make sense of complex systems and respond quickly to any problems.

Practical Example: Observability in a Web Application

Imagine you manage a web application for online shopping. Here’s how you apply key observability concepts:

• Metrics: You track the average response time of your app's homepage, the number of purchase requests per minute, and server CPU usage;
• Logs: Your application writes a log entry every time a user logs in, encounters an error, or completes a transaction; this helps you investigate issues later;
• Traces: You follow a single user's checkout request as it moves through different services (web server, payment processor, inventory system), allowing you to spot where slowdowns or failures occur;
• Alerts: You set up alerts to notify you if the error rate spikes or the homepage response time exceeds two seconds, so you can react quickly;
• Monitoring: You continuously monitor service health, performance, and uptime using automated tools that collect and analyze metrics, logs, and traces;
• Dashboards: You create dashboards that visually display key metrics, recent logs, and alert status, giving you and your team an at-a-glance overview of system health.

With these observability tools, you can quickly detect, understand, and resolve issues, ensuring a smooth experience for your users.