Setup Sentry Tracing

Configure Sentry's performance monitoring to track transactions and spans.

Invoke This Skill When User asks to "enable tracing" or "add performance monitoring" User wants to track API response times, page loads, or latency User asks about tracesSampleRate or custom spans Quick Reference Platform Enable Custom Span JS/Browser tracesSampleRate + browserTracingIntegration() Sentry.startSpan() Next.js tracesSampleRate (auto-integrated) Sentry.startSpan() Node.js tracesSampleRate Sentry.startSpan() Python traces_sample_rate @sentry_sdk.trace or start_span() Ruby traces_sample_rate start_span() JavaScript Setup Enable tracing Sentry.init({ dsn: "YOUR_DSN", tracesSampleRate: 1.0, // 1.0 = 100%, lower for production integrations: [Sentry.browserTracingIntegration()], // Browser/React only tracePropagationTargets: ["localhost", /^https:\/\/api./], });

Custom spans // Async operation const result = await Sentry.startSpan( { name: "fetch-user", op: "http.client" }, async () => { return await fetch("/api/user").then(r => r.json()); } );

// Nested spans await Sentry.startSpan({ name: "checkout", op: "transaction" }, async () => { await Sentry.startSpan({ name: "validate", op: "validation" }, validateCart); await Sentry.startSpan({ name: "payment", op: "payment" }, processPayment); });

Dynamic sampling tracesSampler: ({ name, parentSampled }) => { if (name.includes("healthcheck")) return 0; if (name.includes("checkout")) return 1.0; if (parentSampled !== undefined) return parentSampled; return 0.1; },

Python Setup Enable tracing sentry_sdk.init( dsn="YOUR_DSN", traces_sample_rate=1.0, )

Custom spans

Decorator

@sentry_sdk.trace def expensive_function(): return do_work()

Context manager

with sentry_sdk.start_span(name="process-order", op="task") as span: span.set_data("order.id", order_id) process(order_id)

Dynamic sampling def traces_sampler(ctx): name = ctx.get("transaction_context", {}).get("name", "") if "healthcheck" in name: return 0 if "checkout" in name: return 1.0 return 0.1

sentry_sdk.init(dsn="YOUR_DSN", traces_sampler=traces_sampler)

Ruby Setup Sentry.init do |config| config.dsn = "YOUR_DSN" config.traces_sample_rate = 1.0 end

Common Operation Types op Value Use Case http.client Outgoing HTTP http.server Incoming HTTP db / db.query Database cache Cache operations task Background jobs function Function calls Sampling Recommendations Traffic Rate Development 1.0 Low (<1K req/min) 0.5 - 1.0 Medium (1K-10K) 0.1 - 0.5 High (>10K) 0.01 - 0.1 Distributed Tracing

Configure tracePropagationTargets to send trace headers to your APIs:

tracePropagationTargets: ["localhost", "https://api.yourapp.com"],

For Next.js 14+ App Router, add to root layout:

export async function generateMetadata() { return { other: { ...Sentry.getTraceData() } }; }

Troubleshooting Issue Solution Transactions not appearing Check tracesSampleRate > 0, verify DSN Browser traces missing Add browserTracingIntegration() Distributed traces disconnected Check tracePropagationTargets, CORS headers Too many transactions Lower sample rate, use tracesSampler to filter