RUM Browser Data Collected
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RUM Browser Data Collected

By default, all data collected is kept at full granularity for 15 days. The Datadog Real User Monitoring script sends five main types of events to Datadog:

  • View: Each time a user goes on a page of the setup application, a view event is created. While the user remains on that view, all data collected is attached to that view with the view.id attribute.
  • Resource: A resource event can be generated for images, XHR/Fetch, CSS, or JS libraries. It contains information about the resource, like its name and its associated loading duration.
  • Long task: Any task in a browser that blocks the main thread for more than 50ms is considered a long task and gets a specific event generation.
  • Error: Every time a frontend error is emitted by the browser, RUM catches it and sends it as an Error Event to Datadog.
  • User Action: A User Action event is a custom event that can be generated for a given user action.

A page view represents a user visiting a page from your website. During that page view, errors, resources, long tasks, and user actions get attached to that page view with a unique view.id attribute. Note that a page view gets updated as new events are collected.

For page views, loading performance metrics are collected from both the Paint Timing API and the Navigation Timing API.

Single Page Applications

For Single Page Applications (SPAs), the RUM SDK differentiates between initial_load and route_change navigations with the loading_type attribute. If a click on your web page leads to a new page without a full refresh of the page, the RUM SDK starts a new view event with loading_type:route_change. RUM tracks page changes using the History API.

Datadog provides a unique performance metric, loading_time, which calculates the time needed for a page to load. This metric works both for initial_load and route_change navigations.

How is loading time calculated?

To account for modern web applications, loading time watches for network requests and DOM mutations.

  • Initial Load: Loading Time is equal to whichever is longer:

    • The difference between navigationStart and loadEventEnd.
    • Or the difference between navigationStart and the first time the page has no activity for more than 100ms (activity being defined as ongoing network requests or a DOM mutation).
  • SPA Route Change: Loading Time is equal to the difference between the user click and the first time the page has no activity for more than 100ms (activity being defined as ongoing network requests, or a DOM mutation).

Hash SPA navigation

Frameworks relying on hash (#) navigation are monitored with the RUM SDK automatically. The SDK watches for HashChangeEvent and issues a new view. Events coming from an HTML anchor tag which do not affect the current view context are ignored.

View timing and metrics

AttributeTypeDecription
view.time_spentnumber (ns)Time spent on the current view.
view.loading_timenumber (ns)Time until the page is ready and no network request or DOM mutation is currently occurring. More info from the data collected documentation
view.first_contentful_paintnumber (ns)Time when the browser first renders any text, image (including background images), non-white canvas, or SVG. For more information about browser rendering, see the w3 definition.
view.dom_interactivenumber (ns)The moment when the parser finishes its work on the main document. More info from the MDN documentation
view.dom_content_loadednumber (ns)Event fired when the initial HTML document is completely loaded and parsed, without waiting for non-render blocking stylesheets, images, and subframes to finish loading. More info from the MDN documentation.
view.dom_completenumber (ns)The page and all the subresources are ready. For the user, the loading spinner has stopped spinning. More info from the MDN documentation
view.load_event_endnumber (ns)Event fired when the page is fully loaded. Usually a trigger for additional application logic. More info from the MDN documentation
view.error.countnumberCount of all errors collected for this view.
view.long_task.countnumberCount of all long tasks collected for this view.
view.resource.countnumberCount of all resources collected for this view.
view.action.countnumberCount of all actions collected for this view.

All of your website’s resources are collected by default: images, XHRs, XMLHttpRequest, CSS files, JS assets, and font files.

Detailed network timing data for the loading of an application’s resources are collected with the Performance Resource Timing API.

Resource timing

AttributeTypeDescription
durationnumberEntire time spent loading the resource.
resource.sizenumber (bytes)Resource size.
resource.connect.durationnumber (ns)Time spent establishing a connection to the server (connectEnd - connectStart)
resource.ssl.durationnumber (ns)Time spent for the TLS handshake. If the last request is not over HTTPS, this metric does not appear (connectEnd - secureConnectionStart)
resource.dns.durationnumber (ns)Time spent resolving the DNS name of the last request (domainLookupEnd - domainLookupStart)
resource.redirect.durationnumber (ns)Time spent on subsequent HTTP requests (redirectEnd - redirectStart)
resource.first_byte.durationnumber (ns)Time spent waiting for the first byte of response to be received (responseStart - RequestStart)
resource.download.durationnumber (ns)Time spent downloading the response (responseEnd - responseStart)

Resource attributes

AttributeTypeDescription
resource.typestringThe type of resource being collected (for example, css, javascript, media, XHR, image).
resource.methodstringThe HTTP method (for example POST, GET).
resource.status_codenumberThe response status code.
resource.urlstringThe resource URL.
resource.url_hoststringThe host part of the URL.
resource.url_pathstringThe path part of the URL.
resource.url_queryobjectThe query string parts of the URL decomposed as query params key/value attributes.
resource.url_schemestringThe protocol name of the URL (HTTP or HTTPS).
resource.provider.namestringThe resource provider name. Default is unknown.
resource.provider.domainstringThe resource provider domain.
resource.provider.typestringThe resource provider type (for example first-party, cdn, ad, analytics).

Long tasks are tasks that block the main thread for 50 milliseconds or more. They may cause high input latency, delayed time to interaction, etc. Understand what causes these long tasks in your browser performance profiler.

Long task timing

AttributeTypeDescription
long_task.durationnumberDuration of the long task.

Front-end errors are collected with Real User Monitoring (RUM). The error message and stack trace are included when available.

Error Origins

Front-end errors are split in 4 different categories depending on their error.origin:

  • network: XHR or Fetch errors resulting from AJAX requests. Specific attributes to network errors can be found in the documentation.
  • source: Unhandled exceptions or unhandled promise rejections (source-code related).
  • console: console.error() API calls.
  • custom: Errors sent with the RUM addError API default to custom.

Error attributes

AttributeTypeDescription
error.sourcestringWhere the error originates from (for example, console or network).
error.typestringThe error type (or error code in some cases).
error.messagestringA concise, human-readable, one-line message explaining the event.
error.stackstringThe stack trace or complementary information about the error.

Network errors

Network errors include information about failing HTTP requests. The following facets are also collected:

AttributeTypeDescription
error.resource.status_codenumberThe response status code.
error.resource.methodstringThe HTTP method (for example POST, GET).
error.resource.urlstringThe resource URL.
error.resource.url_hoststringThe host part of the URL.
error.resource.url_pathstringThe path part of the URL.
error.resource.url_queryobjectThe query string parts of the URL decomposed as query params key/value attributes.
error.resource.url_schemestringThe protocol name of the URL (HTTP or HTTPS).
error.resource.provider.namestringThe resource provider name. Default is unknown.
error.resource.provider.domainstringThe resource provider domain.
error.resource.provider.typestringThe resource provider type (for example first-party, cdn, ad, analytics).

Source errors

Source errors include code-level information about the error. More information about the different error types can be found in the MDN documentation.

AttributeTypeDescription
error.typestringThe error type (or error code in some cases).

Automatic collection of actions

Real User Monitoring (RUM) SDKs detect user interactions performed during a user journey. Set the trackInteractions initialization parameter to true to enable this feature.

Note: The trackInteractions initialization parameter enables the collection of user clicks in your application. Sensitive and private data contained on your pages may be included to identify the elements interacted with.

Once an interaction is detected, all new RUM events are attached to the ongoing action until it is considered finished. The action also benefits from its parent view attributes such as browser information, geolocation data, global context.

How is the action loading time calculated?

Once an interaction is detected, the RUM SDK watches for network requests an DOM mutations. It is considered finished once the page has no activity for more than 100ms (activity being defined as ongoing network requests or DOM mutations).

Custom User Actions

Custom User Actions are User Actions declared and sent manually via the addUserAction API. They can send information relative to an event occurring during a user journey, for example, a custom timing or customer cart information.

Action timing and metrics

AttributeTypeDescription
action.loading_timenumber (ns)The loading time of the action. See how it is calculated in the User Action documentation.
action.long_task.countnumberCount of all long tasks collected for this action.
action.resource.countnumberCount of all resources collected for this action.
action.error.countnumberCount of all errors collected for this action.

Action Attributes

AttributeTypeDescription
action.idstringUUID of the user action.
action.typestringType of the user action. For Custom User Actions, it is set to custom.
action.target.namestringElement that the user interacted with. Only for automatically collected actions
action.namestringUser-friendly name created (for example Click on #checkout). For Custom User Actions, the action name given in the API call.

Default attributes

These five event types have attributes attached by default:

Core

Attribute nameTypeDescription
typestringThe type of the event (for example, view or resource).
application.idstringThe Datadog application ID.

View attributes

Attribute nameTypeDescription
view.idstringRandomly generated ID for each page view.
view.loading_typestringThe type of page load: initial_load or route_change. For more information, see the single page applications support docs.
view.referrerstringThe URL of the previous web page from which a link to the currently requested page was followed.
view.urlstringThe view URL.
view.url_hashstringThe hash part of the URL.
view.url_hoststringThe host part of the URL.
view.url_pathstringThe path part of the URL.
view.url_path_groupstringThe automatic URL group generated for similar URLs (for example, /dashboard/? for /dashboard/123 and /dashboard/456).
view.url_queryobjectThe query string parts of the URL decomposed as query params key/value attributes.
view.url_schemeobjectThe scheme part of the URL.

Device

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

Attribute nameTypeDescription
device.typestringThe device type as reported by the User-Agent
device.brandstringThe device brand as reported by the User-Agent.
device.modelstringThe device model as reported by the User-Agent.
device.namestringThe device name as reported by the User-Agent.

Operating system

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

Attribute nameTypeDescription
os.namestringThe OS name as reported by the User-Agent.
os.versionstringThe OS version as reported by the User-Agent.
os.version_majorstringThe OS version major as reported by the User-Agent.

Geolocation

The following attributes are related to the geolocation of IP addresses:

FullnameTypeDescription
geo.countrystringName of the country
geo.country_iso_codestringISO Code of the country (for example, US for the United States, FR for France).
geo.country_subdivisionstringName of the first subdivision level of the country (for example, California in the United States or the Sarthe department in France).
geo.country_subdivision_iso_codestringISO Code of the first subdivision level of the country (for example, CA in the United States or the SA department in France).
geo.continent_codestringISO code of the continent (EU, AS, NA, AF, AN, SA, OC).
geo.continentstringName of the continent (Europe, Australia, North America, Africa, Antartica, South America, Oceania).
geo.citystringThe name of the city (example Paris, New York).

Extra Attribute

In addition to default attributes, add specific global context to all events collected. This provides the ability to analyze the data for a subset of users. For example, group errors by user email, or understand which customers have the worst performance.

Further Reading