When would you use the USE method versus the RED method? [Basic]
Answer
I use RED when I am monitoring a service or API from the user/request perspective, and USE when I am monitoring the health of an underlying resource. During incidents, I usually start with RED and drill into USE.
Technical explanation
For an HTTP service: request rate, error rate, and duration are the primary service health indicators.
For a host, disk, cache, broker, or database pool: utilization, saturation, and errors are more meaningful.
In dashboards, I group them by layer: service RED at the top, dependency RED next, and infrastructure USE below.
Hands-on example
Hands-on: create one dashboard row for checkout RED: RPS, 5xx percent, p95/p99 latency. Create another row for USE: CPU throttling, memory pressure, JVM heap, DB connection pool usage, and Kafka lag. When alerts fire, the layout supports top-down troubleshooting.
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