Prometheus Metrics

Expose process, RED, and custom metrics from Node.

metrics

Detailed Description

Prometheus metrics are numeric time-series data. In Node, prom-client can expose default process metrics plus custom counters, gauges, summaries, and histograms.

Use histograms for latency, counters for totals, and gauges for current values such as queue depth or active connections. Keep label cardinality low to protect Prometheus.

Mental Model

/metrics
-> scrape
-> Prometheus
-> Grafana dashboard

When To Use

->Build production dashboards
->Alert on latency and error rates
->Track Node process health over time

Tools: prom-client, default metrics, histograms

prom-client.js

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Output

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