Set Up Metrics

Sentry metrics help you pinpoint and solve issues that impact user experience and app performance by measuring the data points that are important to you. You can track things like processing time, event size, user signups, and conversion rates, then correlate them back to tracing data in order to get deeper insights and solve issues faster.

Enabling the Metrics Feature

Here's how to add Metrics to your application:

import 'package:sentry_flutter/sentry_flutter.dart';

Future<void> main() async {
  await SentryFlutter.init(
    (options) {
      options.dsn = 'https://examplePublicKey@o0.ingest.sentry.io/0';
      options.enableMetrics = true;
    },
    appRunner: initApp, // Init your App.
  );
}

Emit a Counter

Counters are one of the more basic types of metrics and can be used to count certain event occurrences.

To emit a counter, do the following:

Sentry.metrics().increment(
    'button_login_click', // key
    value: 1,
    unit: null,
    tags: {'provider': 'e-mail'},
);

Emit a Distribution

Distributions help you get the most insights from your data by allowing you to obtain aggregations such as p90, min, max, and avg.

To emit a distribution, do the following:

Sentry.metrics().distribution(
    'image_download_duration', // key
    value: 150,
    unit: DurationSentryMeasurementUnit.milliSecond,
    tags: {'type': 'thumbnail'},
);

Emit a Set

Sets are useful for looking at unique occurrences and counting the unique elements you added.

To emit a set, do the following:

Sentry.metrics().set(
    'user_view', // key
    stringValue: 'jane',
    unit: CustomSentryMeasurementUnit('username'),
    tags: {'page': 'home'},
);

Emit a Gauge

Gauges let you obtain aggregates like min, max, avg, sum, and count. They can be represented in a more space-efficient way than distributions, but they can't be used to get percentiles. If percentiles aren't important to you, we recommend using gauges.

To emit a gauge, do the following:

Sentry.metrics().gauge(
    'page_load', // key
    value: 15,
    unit: DurationSentryMeasurementUnit.milliSecond,
    tags: {'page': '/home'},
);

Emit a Timer

Timers can be used to measure the execution time of a specific block of code. They're implemented like distributions, but measured in seconds.

To emit a timer, do the following:

Sentry.metrics().timing('load_user_profile', function: () {
  //db.load(); ...
});