iOS RUM Data Collection

Overview

Flashcat iOS RUM SDK generates events with associated metrics and attributes. Each RUM event includes default attributes, such as the UIViewController class URL corresponding to the event (view.url) and user information like device type (device.type) and country (geo.country).

Additionally, different event types have specific additional metrics and attributes. For example, the view.time_spent metric is associated with view events, while the resource.method attribute is associated with resource events.

Application Startup

During app startup, the iOS SDK records app startup time and creates a corresponding view. Startup time is measured as the interval from process launch to the first applicationDidBecomeActive notification.

Attribute	Type	Description
`view.is_start_view`	Boolean	Indicates whether this view is the initial view created at app startup.
`action.type`	String	Type of app startup action, value is `application_start`.
`action.loading_time`	Number (nanoseconds)	Time required for app startup.

View Monitoring and App Lifecycle

In iOS apps, views are automatically created when users visit different screens. A view starts recording when the user opens a screen and stops when the view is no longer visible (e.g., user opens another screen).

When a view stops, the SDK doesn't immediately end its lifecycle but keeps it in inactive state for a period to attach subsequent events. If a new view starts during this period, the previous view will fully end. If no new view starts, the previous view will resume to active state.

When the app enters background, the SDK retains the last active view and monitors any new background events. Background time is not counted in the active view's time_spent metric. However, if the user immediately returns to the app, the SDK resumes the original time_spent measurement.

Default Attributes

Flashcat iOS RUM SDK automatically captures the following default attributes, which apply to all RUM event types.

Common Core Attributes

Attribute	Type	Description
`date`	Integer	Event timestamp (in milliseconds).
`type`	String	Event type (such as `session`, `view`, `resource`, `error`, `action`).
`service`	String	Service name that generated this event.
`application.id`	String	Unique identifier for the application.

Device

The following device-related attributes are automatically attached to all events collected by Flashcat:

Attribute	Type	Description
`device.type`	String	Device type (such as `Mobile`, `Tablet`, `TV`, `Desktop`, `Other`).
`device.brand`	String	Device brand, `Apple` for iOS devices.
`device.model`	String	Device model (such as `iPhone`, `iPad`, `iPod Touch`, `Apple TV`).
`device.name`	String	Name of the device.

Operating System

The following OS-related attributes are automatically attached to all events collected by Flashcat:

Attribute	Type	Description
`os.name`	String	Operating system name (such as `iOS`, `iPadOS`, `tvOS`).
`os.version`	String	OS version number (such as `15.4.1`, `16.0`).
`os.version_major`	String	OS major version number (such as `15`, `16`).

Network Connectivity

The following network-related attributes are automatically attached to resource and error events:

Attribute	Type	Description
`connectivity.status`	String	Device network connection status (such as `connected`, `not_connected`).
`connectivity.interfaces`	String array	Available network interface types (such as `wifi`, `cellular`, `ethernet`).
`connectivity.cellular.technology`	String	Cellular network technology type (such as `3G`, `4G`, `LTE`, `5G`).
`connectivity.cellular.carrier_name`	String	Cellular network carrier name.

Geolocation

The following attributes relate to the geographic location of the IP address:

Attribute	Type	Description
`geo.country`	String	Country name.
`geo.country_iso_code`	String	Country ISO code (such as `US`, `CN`).
`geo.country_subdivision`	String	First-level administrative division of the country (such as US states, Chinese provinces).
`geo.continent_code`	String	Continent ISO code (such as `EU`, `AS`).
`geo.continent`	String	Continent name.
`geo.city`	String	City name.

Global User Attributes

You can enable user tracking on all RUM events to correlate user sessions and simplify troubleshooting. User attributes are optional, but it's recommended to provide the following:

Attribute	Type	Description
`usr.id`	String	Unique user identifier.
`usr.name`	String	User-friendly name, displayed by default in RUM UI.
`usr.email`	String	User email address. Email is displayed if no username is provided.

To set user information, see Tracking User Information.

Event-Specific Attributes

Different event types have specific attributes and metrics.

Session Attributes

Attribute	Type	Description
`session.id`	String	Unique session identifier.
`session.type`	String	Session type (such as `user`, `synthetic`).
`session.is_active`	Boolean	Whether the session is active.
`session.initial_view.id`	String	ID of the initial view in the session.
`session.initial_view.url`	String	URL of the initial view in the session.
`session.initial_view.name`	String	Name of the initial view in the session.
`session.last_view.id`	String	ID of the last view in the session.
`session.last_view.url`	String	URL of the last view in the session.
`session.last_view.name`	String	Name of the last view in the session.
`session.has_crash`	Boolean	Whether the session contains crash events.
`session.has_replay`	Boolean	Whether session replay is enabled for the session.

View Attributes

Attribute	Type	Description
`view.id`	String	Unique view identifier.
`view.url`	String	View URL, corresponding to UIViewController class name.
`view.name`	String	Customizable view name.
`view.referrer`	String	URL of the previous view.
`view.action.count`	Number	Number of user actions collected in this view.
`view.error.count`	Number	Number of errors collected in this view.
`view.resource.count`	Number	Number of resources collected in this view.
`view.time_spent`	Number (nanoseconds)	Time user spent on this view.
`view.network_settled_time`	Number (nanoseconds)	Time required for full initialization when view starts.
`view.is_active`	Boolean	Whether the view is active.
`view.is_slow_rendered`	Boolean	Whether view rendering is slow.
`view.crash.count`	Number	Number of crashes that occurred in this view.
`view.frozen_frame.count`	Number	Number of frozen frames in this view.
`view.refresh_rate_average`	Number	Average refresh rate of the view.
`view.refresh_rate_min`	Number	Minimum refresh rate of the view.
`view.memory_average`	Number	Average memory usage of the view.
`view.memory_max`	Number	Maximum memory usage of the view.
`view.cpu_ticks_count`	Number	CPU clock cycles of the view.
`view.cpu_ticks_per_second`	Number	CPU clock cycles per second of the view.

Resource Attributes

Attribute	Type	Description
`resource.id`	String	Unique resource identifier.
`resource.url`	String	Resource URL.
`resource.method`	String	HTTP method (such as `GET`, `POST`, `PATCH`, `DELETE`).
`resource.type`	String	Resource type (such as `xhr`, `image`, `font`, `css`, `js`).
`resource.status_code`	Number	HTTP response status code.
`resource.size`	Number (bytes)	Resource size.
`resource.duration`	Number (nanoseconds)	Total time required to load the resource.
`resource.connect.duration`	Number (nanoseconds)	Time required to establish server connection (connectEnd - connectStart).
`resource.ssl.duration`	Number (nanoseconds)	Time required for TLS handshake.
`resource.dns.duration`	Number (nanoseconds)	Time required for DNS resolution (domainLookupEnd - domainLookupStart).
`resource.first_byte.duration`	Number (nanoseconds)	Time waiting to receive first response byte (responseStart - requestStart).
`resource.download.duration`	Number (nanoseconds)	Time downloading response (responseEnd - responseStart).
`resource.redirect.duration`	Number (nanoseconds)	Time required for subsequent HTTP requests (redirectEnd - redirectStart).
`resource.provider.name`	String	Resource provider name, defaults to `unknown`.
`resource.provider.domain`	String	Resource provider domain.
`resource.provider.type`	String	Resource provider type (such as `first-party`, `cdn`, `ad`, `analytics`).

Error Attributes

Frontend errors are collected through RUM. Error messages and stack traces (if available) are included.

Attribute	Type	Description
`error.source`	String	Error source (such as `webview`, `logger`, `network`).
`error.type`	String	Error type (error code in some cases).
`error.message`	String	Concise, readable single-line error message.
`error.stack`	String	Error stack trace or supplemental information.
`error.issue_id`	String	Unique identifier for the error issue.
`error.category`	String	High-level grouping of error types. Possible values include: `ANR`, `App Hang`, `Exception`, `Watchdog Termination`, `Memory Warning`, `Network`.
`error.file`	String	File where error tracking found the issue.
`error.is_crash`	Boolean	Whether this error caused an app crash.
`freeze.duration`	Number (nanoseconds)	Duration of main thread freeze. Only applicable to App Hang.

Network Errors

Network errors contain information about failed HTTP requests. The following additional attributes are collected:

Attribute	Type	Description
`error.resource.status_code`	Number	HTTP response status code.
`error.resource.method`	String	HTTP method (such as `GET`, `POST`).
`error.resource.url`	String	Resource URL.
`error.resource.provider.name`	String	Resource provider name, defaults to `unknown`.
`error.resource.provider.domain`	String	Resource provider domain.
`error.resource.provider.type`	String	Resource provider type (such as `first-party`, `cdn`, `ad`, `analytics`).

Action Attributes

Attribute	Type	Description
`action.id`	String	Unique user action identifier.
`action.type`	String	User action type (such as `tap`, `application_start`).
`action.name`	String	User action name.
`action.target.name`	String	Element user interacted with. Only for automatically collected actions.
`action.loading_time`	Number (nanoseconds)	Action loading time.
`action.resource.count`	Number	Number of resources triggered by this action.
`action.error.count`	Number	Number of errors triggered by this action.
`action.long_task.count`	Number	Number of long tasks triggered by this action.

Crash Attributes

When an app crashes, the following additional attributes are collected:

Attribute	Type	Description
`error.signal`	String	Signal name that caused the crash (such as `SIGABRT`, `SIGSEGV`).
`error.binary_images`	Array	List of binary images loaded at crash time.
`error.threads`	Array	State of all threads at crash time.
`error.meta`	Object	Crash-related metadata.

Data Storage

Before uploading to Flashcat, data is stored in plain text in the app sandbox's cache directory (Library/Caches). Other apps installed on the device cannot read this directory.

To ensure the SDK doesn't occupy excessive disk space, outdated data is automatically discarded. The SDK follows these rules:

When network is available and device battery is sufficient, data is sent in batches.

If network is unavailable or data upload fails, batches are retained until successfully sent.

Data exceeding a certain time limit is automatically cleaned up.

This means data won't be lost even if users use your app while offline.

More Information

iOS SDK Integration: Learn how to integrate Flashcat RUM SDK in iOS apps

iOS SDK Advanced Configuration: Learn how to configure advanced SDK features

RUM Data Collection: Learn about RUM general data collection mechanism

Data Collection

Overview#

Application Startup#

View Monitoring and App Lifecycle#

Default Attributes#

Common Core Attributes#

Device#

Operating System#

Network Connectivity#

Geolocation#

Global User Attributes#

Event-Specific Attributes#

Session Attributes#

View Attributes#

Resource Attributes#

Error Attributes#

Network Errors#

Action Attributes#

Crash Attributes#

Data Storage#

More Information#