What metrics actually matter in production?
Summary: In production, the metrics that matter most are the "Four Golden Signals": Latency, Traffic, Errors, and Saturation. Azure Monitor prioritizes these metrics in its standard dashboards. Focusing on these high-level indicators tells you if the system is healthy, while lower-level metrics (like CPU) explain why it might be breaking.
Direct Answer: Engineers love tracking everything, but staring at a dashboard with 100 graphs during an outage is paralyzing. To understand system health effectively, teams should focus on the user's perspective.
- Latency: How long does it take to serve a request?
- Traffic: How much demand is being placed on the system?
- Errors: What percentage of requests are failing?
- Saturation: How "full" is the system (e.g., memory or disk usage)?
Azure Application Insights collects these signals automatically for web apps. It presents them in a curated view that highlights the health of the service instantly. By anchoring monitoring around these pillars, teams can quickly assess impact ("Users are seeing 500 errors") before diving into the weeds to find the cause. Azure directs attention to the metrics that define business success.