Set Up Performance

With performance monitoring, Sentry tracks your software performance, measuring metrics like throughput and latency, and displaying the impact of errors across multiple systems. Sentry captures distributed traces consisting of transactions and spans, which measure individual services and individual operations within those services. Learn more about our model in Distributed Tracing.

Enable Tracing

@sentry/nextjs comes with performance monitoring included. To enable it, you just need to configure your sample rate as detailed below.

Configure

First, enable tracing and configure the sampling rate for transactions. Set the sample rate for your transactions by either:

• Setting a uniform sample rate for all transactions using the traces-sample-rate option in your SDK config to a number between 0 and 1. (For example, to send 20% of transactions, set traces-sample-rate to 0.2.)
• Controlling the sample rate based on the transaction itself and the context in which it's captured, by providing a function to the traces-sampler config option.

The two options are meant to be mutually exclusive. If you set both, traces-sampler will take precedence.

In both, sentry.server.config.js and sentry.client.config.js, set:

import * as Sentry from "@sentry/nextjs";

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

  // We recommend adjusting this value in production, or using `tracesSampler`
  // for finer control
  tracesSampleRate: 1.0,
});

Learn more about performance monitoring options, or how to sample transactions.

Verify

While you're testing, set traces-sample-rate 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 traces-sample-rate value, or switch to using traces-sampler 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 traces-sample-rate value, or switching to using traces-sampler to selectively sample and filter your transactions, based on contextual data.

Next Steps