> ## Documentation Index
> Fetch the complete documentation index at: https://docs.flashduty.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Performance Impact

> Learn about the performance impact of the Flashduty iOS RUM SDK on CPU, memory, launch time, package size, and network usage, along with optimization recommendations.

## Overview

When integrating any SDK into an iOS application, understanding its performance impact is crucial for maintaining a good user experience. The Flashduty RUM SDK is designed with the goal of minimizing performance overhead and provides transparent measurement data to help you evaluate whether the SDK meets your application's performance budget.

<Check>
  The SDK uses asynchronous processing mechanisms, with all data processing performed in background queues without blocking the main thread.
</Check>

## Performance Benchmark

To evaluate the actual performance impact of the SDK on your application, we conducted performance benchmarks under typical usage scenarios. The following SDK features were enabled during testing:

* Basic RUM monitoring: View, action, and resource tracking
* Distributed tracing

The SDK was initialized with default configuration and simulated common user operations (such as page views, scrolling lists, network requests, etc.).

### Test Results

| Metric            | With SDK                       | Without SDK | Impact                   |
| ----------------- | ------------------------------ | ----------- | ------------------------ |
| Peak CPU Usage    | \~44%                          | \~40%       | +4%                      |
| Peak Memory Usage | \~72 MB                        | \~68 MB     | +4 MB                    |
| App Launch Time   | \~0.9 ms                       | \~0.65 ms   | +0.25 ms                 |
| Package Size      | +1.4 MB                        | -           | \~1.4 MB                 |
| Network Usage     | \~22 KB sent / \~2 KB received | -           | Varies with event volume |

<Note>
  The above data are reference values under typical scenarios; actual impact may vary depending on application complexity, device performance, and SDK configuration.
</Note>

### Performance Impact Details

<AccordionGroup>
  <Accordion title="CPU Usage" icon="microchip">
    The SDK's CPU impact primarily comes from:

    * Event collection and processing
    * Data batching and compression
    * Network request reporting

    The SDK uses asynchronous processing mechanisms, with all data processing performed in background queues without blocking the main thread, ensuring it does not affect the application's UI responsiveness.
  </Accordion>

  <Accordion title="Memory Usage" icon="memory">
    The SDK uses a fixed-size memory buffer to store pending event data, which does not grow indefinitely over time. Stale data is automatically cleaned up to ensure it does not consume excessive memory.
  </Accordion>

  <Accordion title="Launch Time" icon="rocket">
    The SDK initialization process is optimized, with impact on application launch time controlled to sub-millisecond level.

    <Tip>
      It is recommended to initialize the SDK as early as possible in `AppDelegate`'s `didFinishLaunchingWithOptions` to capture the complete application startup process.
    </Tip>
  </Accordion>

  <Accordion title="Package Size" icon="box">
    The SDK uses a modular design, allowing you to include only the necessary functional modules:

    | Dependency Name           | Import Name              | Description                   |
    | ------------------------- | ------------------------ | ----------------------------- |
    | `FlashcatCore`            | `DatadogCore`            | Core functionality (required) |
    | `FlashcatRUM`             | `DatadogRUM`             | RUM monitoring                |
    | `FlashcatTrace`           | `DatadogTrace`           | Distributed tracing           |
    | `FlashcatWebViewTracking` | `DatadogWebViewTracking` | WebView tracking              |

    Including only the necessary modules can minimize the impact on package size.
  </Accordion>

  <Accordion title="Network Usage" icon="wifi">
    The SDK employs the following strategies to optimize network usage:

    * **Batch reporting**: Events are cached locally first and sent in batches to reduce the number of network requests
    * **Data compression**: Reported data is compressed to reduce transmission traffic
    * **Intelligent scheduling**: Upload timing is intelligently scheduled based on network status and battery level
  </Accordion>
</AccordionGroup>

## Performance Optimization Recommendations

If you have specific performance requirements, consider the following optimization measures:

<Steps>
  <Step title="Adjust Sampling Rate">
    Reduce the number of collected events by configuring the sampling rate:

    ```swift theme={null}
    RUM.enable(
        with: RUM.Configuration(
            applicationID: "<RUM_APPLICATION_ID>",
            sessionSampleRate: 80 // Sample 80% of sessions
        )
    )
    ```
  </Step>

  <Step title="Enable Features on Demand">
    Only enable necessary tracking features:

    ```swift theme={null}
    RUM.enable(
        with: RUM.Configuration(
            applicationID: "<RUM_APPLICATION_ID>",
            uiKitViewsPredicate: nil, // Disable automatic view tracking
            uiKitActionsPredicate: nil // Disable automatic action tracking
        )
    )
    ```
  </Step>

  <Step title="Disable Background Event Tracking">
    If you don't need to track background events:

    ```swift theme={null}
    RUM.enable(
        with: RUM.Configuration(
            applicationID: "<RUM_APPLICATION_ID>",
            trackBackgroundEvents: false
        )
    )
    ```
  </Step>
</Steps>

## Offline Data Storage

When the device is offline, the SDK stores data locally with strict storage space limits:

<Check>
  * Uses fixed-size disk cache
  * Expired data is automatically cleaned up
  * Cached data will not affect device storage space
</Check>

## Battery Consumption

The SDK is designed with battery consumption in mind:

* Automatically reduces upload frequency when battery level falls below a certain threshold
* Leverages system background task mechanisms for data reporting
* Avoids frequent device wake-ups

## Related Documentation

<CardGroup cols={2}>
  <Card title="SDK Integration Guide" icon="plug" href="/en/rum/sdk/ios/sdk-integration">
    Learn how to integrate the SDK
  </Card>

  <Card title="Advanced Configuration" icon="sliders" href="/en/rum/sdk/ios/advanced-config">
    Learn about SDK advanced configuration options
  </Card>

  <Card title="Data Collection" icon="database" href="/en/rum/sdk/ios/data-collection">
    Learn what data the SDK collects
  </Card>

  <Card title="Compatibility" icon="check-circle" href="/en/rum/sdk/ios/compatible">
    Learn about supported platform versions
  </Card>
</CardGroup>