Performance Metrics

Sentry's SDKs support sending performance metrics data to Sentry. These are numeric values attached to transactions that are aggregated and displayed in Sentry.

If configured, the Cocoa SDK automatically collects the following performance metrics:

• Cold and warm app start time
• Slow and frozen frame rendering

Custom Measurements

In addition to automatic performance metrics, the SDK supports setting custom performance measurements on transactions. This allows you to define measurements that are important to your application and send them to Sentry.

To set a performance measurement, you need to supply the following:

• name (string)
• value (any numeric type - float, integer, etc.)
• unit (string, defaults to the string none if omitted)

Sentry supports adding arbitrary custom units, but we recommend using one of the supported units listed below.

Adding custom measurements is supported in Sentry's Cocoa SDK, version 7.28.0 and above.

import Sentry

let span = SentrySDK.span;

// Record amount of memory used
span?.setMeasurement(name: "memory_used", value: 64, unit: MeasurementUnitInformation.megabyte);

// Record time it took to load user profile
span?.setMeasurement(name: "user_profile_loading_time", value: 1.3, unit: MeasurementUnitDuration.second);

// Record number of times the screen was loaded
span?.setMeasurement(name: "screen_load_count", value: 4);

Supported Measurement Units

Units augment metric values by giving meaning to what otherwise might be abstract numbers. Adding units also allows Sentry to offer controls - unit conversions, filters, and so on - based on those units. For values that are unitless, you can supply an empty string or none.

Duration Units

• nanosecond
• microsecond
• millisecond
• second
• minute
• hour
• day
• week

Information Units

• bit
• byte
• kilobyte
• kibibyte
• megabyte
• mebibyte
• gigabyte
• gibibyte
• terabyte
• tebibyte
• petabyte
• pebibyte
• exabyte
• exbibyte

Fraction Units

• ratio
• percent

If you want to explore further, you can find details about supported units in our event ingestion documentation.