[DOCS-12674] Update RUM alerting guide

content/en/real_user_monitoring/guide/alerting-with-rum.md

@@ -1,6 +1,5 @@
 ---
 title: Alerting With RUM Data
-
 description: Guide for creating alerts on RUM events.
 further_reading:
 - link: '/real_user_monitoring/platform/dashboards/'
@@ -16,75 +15,97 @@
 
 ## Overview
 
-Real User Monitoring allows you to create alerts which notify you about atypical behavior in your applications. You can create RUM monitors with complex conditions, predefined thresholds, and multiple queries to calculate averages, ratios, and performance indicator metrics (such as Apdex).
+Real User Monitoring (RUM) lets you create alerts about atypical behavior in your applications. With [RUM without Limits™][1], use metric-based monitors to alert on your full unsampled traffic with 15-month retention. Metric-based monitors support advanced alerting conditions such as anomaly detection
 
-## Define your search query
+## Create a RUM monitor
 
-To create a RUM monitor, see the [RUM Monitor documentation][1] first. You can add one or many queries to filter through your RUM data in the [RUM Explorer][2]. For each query, you can scope it on an application level or a more granular level like a specific page.
+To create a RUM monitor in Datadog, first navigate to [Monitors > New Monitor > Real User Monitoring][2].
 
-You can use any facets that RUM collects, including [custom facets and measures][3]. Use the `measure by` field to measure view-related counts such as load time, time spent, and error count.
+From there, you can click **New Monitor**, then:
 
-{{< img src="real_user_monitoring/guide/alerting-with-rum/high-rum-views-errors.png" alt="Search query for an alert where a view exceeds more than eight errors" style="width:100%;">}}
+- **[Start with a template][3]**: Datadog provides several pre-built templates for common RUM monitoring scenarios like error rates, performance vitals, or availability checks. Browse the [full template gallery][3] to get started.
+- **Build a custom monitor**: Choose from out-of-the-box metrics or custom metrics, then scope to your application, specific pages, or views.
 
-The example above is a search query for a RUM monitor configured for views on the Shopist iOS application with facets such as `Application ID` and `View Path`. This example monitor alerts when a view has a high amount of errors (for example, more than 8).
+Learn more about [creating RUM Monitors][4].
 
-## Export your query to a monitor
+## Metric-based and event-based monitors
 
-You can export search queries from the [RUM Explorer][2] to a monitor to retain all the context for the query.
+For RUM without Limits™ customers, metric-based monitors are the recommended standard for the following benefits:
 
-{{< img src="real_user_monitoring/guide/alerting-with-rum/export-to-monitor-3.mp4" alt="Export button to the right hand corner of the RUM Explorer" video="true" style="width:100%;" >}}
+- **Visibility into your full traffic**: Metrics are computed over your full, unsampled traffic before retention filters apply to provide broader visibility into application health
+- **Reduce the risk of missing issues**: Event-based monitors depend on retention filters and can miss issues if relevant events aren't indexed
+- **Advanced capabilities**: Metric-based monitors support anomaly detection, outlier detection, and forecasts
+- **15-month retention**: Metrics provide long-term visibility into trends and patterns
 
-The example above is a search query for a RUM monitor configured for images that are larger than 1Mb. Large images may reduce your application's performance. 
+Datadog recommends using **event-based monitors** when you need to alert on data that is indexed, such as specific events or attributes that are not available in metric form. When using event-based monitors, configure retention filters to ensure meaningful data is available.
 
-Click the **Export** button to export your search query to a pre-configured RUM monitor. For more information, see [Export RUM Events][4].
+To create an event-based monitor, you can export search queries from the [RUM Explorer][5]. Use any facets that RUM collects, including [custom facets and measures][6], and the `measure by` field for view-related counts like load time and error count.
 
-## Route your alert
+## Export queries from the RUM homepage
 
-Once you have created an alert, route the alert to an individual or a team channel by writing a message and sending a test notification. For more information, see [Notifications][5].
+You can export existing queries from the [RUM homepage][12] to create a monitor with all the query and context preserved. For customers on [RUM without Limits™][1], the queries powering up those widgets are based on the [out-of-the-box metrics][13]. For customers on the legacy model, they are based on [events][14].
 
-## Alerting examples
+{{< img src="real_user_monitoring/guide/alerting-with-rum/create-monitor-homepage.png" alt="Export button to the right hand corner of the RUM Explorer" style="width:100%;" >}}
 
-The following examples highlight use cases for alerting with your RUM data.
+Click the **Export > Create Monitor** button to export a widget to a pre-configured RUM monitor. For more information, see [Export RUM Events][7]. Remember that event-based monitors should be used alongside properly configured retention filters.
 
-### Revenue dips
+## Route your alert
 
-With RUM's [global context][6], you can enrich your RUM events with business-specific attributes such as the purchase amount for each user.
+After creating an alert, route it to people or channels by writing a message and sending a test notification. For more information, see [Notifications][8].
 
-Assuming that most users of the example application spend between $800 to $1000, this example shows a RUM monitor configured to spot deviations in users' spending patterns week by week. 
+## Alerting examples
 
-{{< img src="real_user_monitoring/guide/alerting-with-rum/revenue-dips-example-monitor.png" alt="RUM Monitor for revenue dips" style="width:100%;" >}}
+The following examples highlight common use cases for RUM monitors. For RUM without Limits customers, these scenarios can be implemented using metric-based monitors for visibility into your full traffic and advanced alerting capabilities.
 
-To compare this week's spending to last week's spending, add a function such as `week_before` next to the `roll up every` field. You can also apply the absolute value to calculate the difference in purchasing amount from last week to this week. When the week-over-week difference exceeds $50, the alert sends a notification.
+### Traffic monitoring with anomaly detection
 
-{{< img src="real_user_monitoring/guide/alerting-with-rum/revenue-dips-example-alerting-conditions.png" alt="Alerting conditions for a RUM monitor about revenue dips" style="width:100%;" >}}
+Session count monitoring helps teams detect unusual traffic patterns that could indicate issues or opportunities. Unlike threshold-based alerts, anomaly detection automatically learns normal traffic patterns and alerts when behavior deviates significantly.
 
-### Error rates
+This example shows a RUM monitor using anomaly detection to track session counts over time. The monitor can be scoped to a specific application or service to detect unexpected drops or spikes in user traffic. Anomaly detection is particularly useful for traffic monitoring because it adapts to daily and weekly patterns, reducing false alerts from expected traffic variations.
 
-The ratio of errors to requests allows you to calculate what percentage of requests are resulting in errors.
+{{< img src="real_user_monitoring/guide/alerting-with-rum/traffic-anomaly.png" alt="RUM monitor query showing count of sessions metric summed by application name, with anomaly alert conditions configured to trigger when values deviate from expected patterns" style="width:100%;" >}}
 
-This example shows a RUM monitor for the error rate of the `/cart` page on a sample Shop.ist application.
+### Crash-free sessions
 
-{{< img src="real_user_monitoring/guide/alerting-with-rum/error-rate-example-monitor.png" alt="RUM monitor for error rates" style="width:100%;" >}}
+The crash-free rate helps teams track how often mobile sessions complete without errors.
+
+This example uses mobile RUM to evaluate application stability across release versions. The monitor is filtered to a specific application (for example, `Shop.ist iOS`) and grouped by `version` to help identify regressions tied to specific releases. The query combines crash-free sessions and total sessions to calculate the crash-free rate as a percentage.
+
+{{< img src="real_user_monitoring/guide/alerting-with-rum/crash-free-sessions.png" alt="Query view showing two RUM metric queries for crash-free and inactive sessions, filtered on the Shop.ist iOS app and grouped by version, combined into a formula to calculate a crash-free rate." style="width:100%;" >}}
 
 ### Performance vitals
 
-Real User Monitoring measures, calculates, and scores application performance as [Core Web Vitals][7] and [Mobile Vitals][8]. For example, Largest Contentful Paint (LCP) measures loading performance and is benchmarked at 2.5 seconds when the page starts loading.
+Real User Monitoring measures, calculates, and scores application performance as [Core Web Vitals][10] and [Mobile Vitals][11]. For example, Largest Contentful Paint (LCP) measures loading performance. A widely used benchmark is 2.5 seconds when the page starts loading.
 
-This example shows a RUM monitor for the LCP of the `/cart` page on a sample Shop.ist application.
+This example shows a RUM monitor for the LCP metric filtered to a specific application (for example, `Shop.ist`) and grouped by `view name` to track performance across different pages. Grouping by view name helps pinpoint which pages have performance issues.
 
-{{< img src="real_user_monitoring/guide/alerting-with-rum/high-largest-contentful-paint-example-monitor.png" alt="RUM monitor for high Largest Contentful Paint" style="width:100%;" >}}
+{{< img src="real_user_monitoring/guide/alerting-with-rum/core-web-vital.png" alt="RUM monitor query showing Interaction to Next Paint (INP) metric with p75 aggregation grouped by view name, with threshold alert conditions set for warning and alert levels" style="width:100%;" >}}
+
+This example monitor warns when the LCP takes 2 seconds to load and alerts when the LCP takes longer than 2.5 seconds to load. With metric-based monitors, you can also use anomaly detection to help identify when performance metrics deviate from normal patterns, or use forecast alerts to predict when thresholds might be breached.
+
+### Error rates
 
-This example monitor warns when the LCP takes 2 seconds to load and alerts when the LCP takes longer than 2.5 seconds to load.
+The ratio of errors to requests shows what percentage of requests result in errors.
+
+This example shows a RUM monitor for the error rate of the `/cart` page on a sample Shop.ist application.
+
+{{< img src="real_user_monitoring/guide/alerting-with-rum/error-rate-example-monitor.png" alt="RUM monitor for error rates" style="width:100%;" >}}
 
-## Further Reading
+## Further reading
 
 {{< partial name="whats-next/whats-next.html" >}}
 
-[1]: /monitors/types/real_user_monitoring/#create-a-rum-monitor
-[2]: https://app.datadoghq.com/rum/explorer
-[3]: /real_user_monitoring/guide/send-rum-custom-actions/#create-facets-and-measures-on-attributes
-[4]: /real_user_monitoring/explorer/export/
-[5]: /monitors/notify/
-[6]: /real_user_monitoring/application_monitoring/browser/advanced_configuration/?tab=npm#global-context
-[7]: /real_user_monitoring/application_monitoring/browser/monitoring_page_performance/#all-performance-metrics
-[8]: /real_user_monitoring/android/mobile_vitals/
+[1]: /real_user_monitoring/rum_without_limits
+[2]: https://app.datadoghq.com/monitors/create/rum
+[3]: https://app.datadoghq.com/monitors/templates?q=real%20user%20monitoring&origination=installed&p=1
+[4]: /monitors/types/real_user_monitoring/#create-a-rum-monitor
+[5]: https://app.datadoghq.com/rum/explorer
+[6]: /real_user_monitoring/guide/send-rum-custom-actions/#create-facets-and-measures-on-attributes
+[7]: /real_user_monitoring/explorer/export/
+[8]: /monitors/notify/
+[9]: /real_user_monitoring/application_monitoring/browser/advanced_configuration/?tab=npm#global-context
+[10]: /real_user_monitoring/application_monitoring/browser/monitoring_page_performance/#all-performance-metrics
+[11]: /real_user_monitoring/android/mobile_vitals/
+[12]: https://app.datadoghq.com/rum/performance-monitoring
+[13]: /real_user_monitoring/rum_without_limits/metrics
+[14]: /real_user_monitoring/explorer/events/