Set Up Tracing

With tracing, Sentry automatically tracks your software performance across your application services, measuring metrics like throughput and latency, and displaying the impact of errors across multiple systems.

Configure

const Sentry = require("@sentry/node");

Sentry.init({
  dsn: "https://examplePublicKey@o0.ingest.sentry.io/0",

  // Add Tracing by setting tracesSampleRate
  // We recommend adjusting this value in production
  tracesSampleRate: 1.0,

  // Alternatively, to control sampling dynamically
  // tracesSampler: samplingContext => { /* ... */ }
});

• You can establish a uniform sample rate for all transactions by setting the tracesSampleRate option in your SDK config to a number between 0 and 1. (For example, to send 20% of transactions, set tracesSampleRate to 0.2.)
• For more granular control over sampling, you can set the sample rate based on the transaction itself and the context in which it's captured, by providing a function to the tracesSampler config option.

The two options are mutually exclusive. If both are set, tracesSampler will take precedence.

You can find more in-depth explanations and examples about sampling configuration in Configure Sampling.

Distributed Tracing

Sentry captures distributed traces consisting of transactions and spans, which measure individual services and individual operations within those services, respectively. Learn more about our model in Distributed Tracing.

Verify

While you're testing, set tracesSampleRate to 1.0, as that ensures that every transaction will be sent to Sentry. Once testing is complete, you may want to set a lower tracesSampleRate value, or switch to using tracesSampler to selectively sample and filter your transactions, based on contextual data.

If you leave your sample rate at 1.0, a transaction will be sent every time a user loads a page or navigates within your app. Depending on the amount of traffic your application gets, this may mean a lot of transactions. If you have a high-load, backend application, you may want to consider setting a lower tracesSampleRate value, or switching to using tracesSampler to selectively sample and filter your transactions, based on contextual data.

Custom Instrumentation

You can also manually start spans to instrument specific parts of your code. This is useful when you want to measure the performance of a specific operation or function.

• Tracing APIs: Find information about APIs for custom tracing instrumentation
• Instrumentation: Find information about manual instrumentation with the Sentry SDK
• Sending Span Metrics: Learn how to capture metrics on your spans

Disabling Tracing

If you want to disable tracing, you should not set tracesSampleRate at all. Setting it to 0 will not disable tracing, it will simply never send any traces to Sentry. Instead, neither tracesSampleRate nor tracesSampler should be defined in your SDK config to fully disable tracing.

Next Steps