How to use
- Copy the installation command and review the source package before installing it in your own agent environment.
- Check the source document for required tools, credentials and supported hosts.
- Describe your input and desired deliverable; review the output against the source material.
npx skills add https://github.com/jeffallan/claude-skills --skill monitoring-expertBefore you start
- Installation does not include a model subscription, API allowance or permission to access your files.
- Repository stars and installation counts describe activity, not an independent quality or security test.
Original skill document
Rendered from the source repository. Headings, examples, code, tables, links, and referenced images are preserved.
Monitoring Expert
Observability and performance specialist implementing comprehensive monitoring, alerting, tracing, and performance testing systems.
Core Workflow
- Assess — Identify what needs monitoring (SLIs, critical paths, business metrics)
- Instrument — Add logging, metrics, and traces to the application (see examples below)
- Collect — Configure aggregation and storage (Prometheus scrape, log shipper, OTLP endpoint); verify data arrives before proceeding
- Visualize — Build dashboards using RED (Rate/Errors/Duration) or USE (Utilization/Saturation/Errors) methods
- Alert — Define threshold and anomaly alerts on critical paths; validate no false-positive flood before shipping
Quick-Start Examples
Structured Logging (Node.js / Pino)
js
import pino from 'pino';
const logger = pino({ level: 'info' });
// Good — structured fields, includes correlation ID
logger.info({ requestId: req.id, userId: req.user.id, durationMs: elapsed }, 'order.created');
// Bad — string interpolation, no correlation
console.log(`Order created for user ${userId}`);Prometheus Metrics (Node.js)
js
import { Counter, Histogram, register } from 'prom-client';
const httpRequests = new Counter({
name: 'http_requests_total',
help: 'Total HTTP requests',
labelNames: ['method', 'route', 'status'],
});
const httpDuration = new Histogram({
name: 'http_request_duration_seconds',
help: 'HTTP request latency',
labelNames: ['method', 'route'],
buckets: [0.05, 0.1, 0.3, 0.5, 1, 2, 5],
});
// Instrument a route
app.use((req, res, next) => {
const end = httpDuration.startTimer({ method: req.method, route: req.path });
res.on('finish', () => {
httpRequests.inc({ method: req.method, route: req.path, status: res.statusCode });
end();
});
next();
});
// Expose scrape endpoint
app.get('/metrics', async (req, res) => {
res.set('Content-Type', register.contentType);
res.end(await register.metrics());
});OpenTelemetry Tracing (Node.js)
js
import { NodeSDK } from '@opentelemetry/sdk-node';
import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-http';
import { trace } from '@opentelemetry/api';
const sdk = new NodeSDK({
traceExporter: new OTLPTraceExporter({ url: 'http://jaeger:4318/v1/traces' }),
});
sdk.start();
// Manual span around a critical operation
const tracer = trace.getTracer('order-service');
async function processOrder(orderId) {
const span = tracer.startSpan('order.process');
span.setAttribute('order.id', orderId);
try {
const result = await db.saveOrder(orderId);
span.setStatus({ code: SpanStatusCode.OK });
return result;
} catch (err) {
span.recordException(err);
span.setStatus({ code: SpanStatusCode.ERROR });
throw err;
} finally {
span.end();
}
}Prometheus Alerting Rule
yaml
groups:
- name: api.rules
rules:
- alert: HighErrorRate
expr: |
rate(http_requests_total{status=~"5.."}[5m])
/ rate(http_requests_total[5m]) > 0.05
for: 2m
labels:
severity: critical
annotations:
summary: "Error rate above 5% on {{ $labels.route }}"k6 Load Test
js
import http from 'k6/http';
import { check, sleep } from 'k6';
export const options = {
stages: [
{ duration: '1m', target: 50 }, // ramp up
{ duration: '5m', target: 50 }, // sustained load
{ duration: '1m', target: 0 }, // ramp down
],
thresholds: {
http_req_duration: ['p(95)<500'], // 95th percentile < 500 ms
http_req_failed: ['rate<0.01'], // error rate < 1%
},
};
export default function () {
const res = http.get('https://api.example.com/orders');
check(res, { 'status is 200': (r) => r.status === 200 });
sleep(1);
}Reference Guide
Load detailed guidance based on context:
| Topic | Reference | Load When |
|---|---|---|
| Logging | references/structured-logging.md | Pino, JSON logging |
| Metrics | references/prometheus-metrics.md | Counter, Histogram, Gauge |
| Tracing | references/opentelemetry.md | OpenTelemetry, spans |
| Alerting | references/alerting-rules.md | Prometheus alerts |
| Dashboards | references/dashboards.md | RED/USE method, Grafana |
| Performance Testing | references/performance-testing.md | Load testing, k6, Artillery, benchmarks |
| Profiling | references/application-profiling.md | CPU/memory profiling, bottlenecks |
| Capacity Planning | references/capacity-planning.md | Scaling, forecasting, budgets |
Constraints
MUST DO
- Use structured logging (JSON)
- Include request IDs for correlation
- Set up alerts for critical paths
- Monitor business metrics, not just technical
- Use appropriate metric types (counter/gauge/histogram)
- Implement health check endpoints
MUST NOT DO
- Log sensitive data (passwords, tokens, PII)
- Alert on every error (alert fatigue)
- Use string interpolation in logs (use structured fields)
- Skip correlation IDs in distributed systems
Maintained by @jeffallan, Principal Consultant at Synergetic Solutions
