Set Up Profiling

通过性能分析，Sentry 通过在各种环境中采样程序的调用栈来跟踪软件的性能。此功能收集关于代码的功能级信息，使你能够微调程序的性能。Sentry 的性能分析器捕获函数调用及其确切位置，对它们进行聚合，并显示程序中最常见的代码路径。这突出了你可以优化的区域，以帮助提高代码性能和用户满意度，同时降低成本。

Enable Tracing

Profiling depends on Sentry’s Tracing product being enabled beforehand. To enable tracing in the SDK:

import Sentry

SentrySDK.start { options in
    options.dsn = "https://examplePublicKey@o0.ingest.sentry.io/0"
    options.tracesSampleRate = 1.0
}

Check out the tracing setup documentation for more detailed information on how to configure sampling. Setting the sample rate to 1.0 means all transactions will be captured.

By default, some transactions will be created automatically for common operations like loading a view controller/activity and app startup.

Enable Profiling

import Sentry

SentrySDK.start { options in
    options.dsn = "https://examplePublicKey@o0.ingest.sentry.io/0"
    options.tracesSampleRate = 1.0 // tracing must be enabled for profiling
    options.profilesSampleRate = 1.0 // see also `profilesSampler` if you need custom sampling logic
    options.enableAppLaunchProfiling = true // experimental new feature to start profiling in the pre-main launch phase
}

Enable Launch Profiling

(New in version 8.21.0)

Normally, a profile can only be taken during a trace span after the SDK has been initialized. Now, you can configure the SDK to automatically profile certain app launches.

To set up launch profiling, use the enableAppLaunchProfiling option and configure the sample rates for traces and profiles with SentrySDK.startWithOptions to determine if the subsequent app launch should be automatically profiled. This allows you to gather information on what is going on in your app even before main is called, making it easier to diagnose issues with slow app launches.

If you use SentryOptions.tracesSampler or SentryOptions.profilesSampler, it will be invoked after you call SentrySDK.startWithOptions, with SentryTransactionContext.forNextAppLaunch set to true indicating that it's evaluating a launch profile sampling decision. If instead you simply set SentryOptions.tracesSampleRate and SentryOptions.profilesSampleRate, those numerical rates will be used directly.

Currently, launch profiles are attached to a special performance transaction operation called app.launch and displayed in the product simply as launch.

Continuous Profiling

(New in version 8.36.0)

The current profiling implementation stops the profiler automatically after 30 seconds (unless you manually stop it earlier). Naturally, this limitation makes it difficult to get full coverage of your app's execution. We now offer an experimental continuous mode, where profiling data is periodically uploaded while running, with no limit to how long the profiler may run.

Previously, profiles only ran in tandem with performance transactions that were started either automatically or manually with SentrySDK.startTransaction. Now, you can start and stop the profiler directly with SentrySDK.startProfiler and SentrySDK.stopProfiler. You can also start a profile at app launch by setting SentryOptions.enableAppLaunchProfiling = true in your call to SentrySDK.startWithOptions.

Continuous profiling mode is enabled by default, requiring no changes to SentryOptions when you start the SDK to opt in. If you had previously set SentryOptions.profilesSampleRate or SentryOptions.profilesSampler to use transaction-based profiling, then remove those lines of code from your configuration.

These new APIs do not offer any sampling functionality—every call to start the profiler will start it, and the same goes for launch profiles if you've configured that. If you are interested in reducing the amount of profiles that run, you must take care to do it at the callsites.

Continuous profiling has implications for your org's billing structure. This feature is only available for subscription plans that enrolled after June 5, 2024.