Prometheus Patterns

PromQL Essentials

Rate and Error Calculations

# Request rate (per second, 5m window)
rate(http_requests_total[5m])

# Error rate percentage
sum(rate(http_requests_total{status=~"5.."}[5m]))
/ sum(rate(http_requests_total[5m])) * 100

# P99 latency from histogram
histogram_quantile(0.99, sum(rate(http_request_duration_seconds_bucket[5m])) by (le))