[apm] Update Applications nav subsection from "Services" to "Service …

…inventory" (#4517)

* update references to services item in serverless side bar

* update references to services item in stateful side bar

* scale back serverless updates

(cherry picked from commit a24b240)

# Conflicts:
#	docs/en/serverless/apm/apm-find-transaction-latency-and-failure-correlations.asciidoc
#	docs/en/serverless/apm/apm-get-started.asciidoc
#	docs/en/serverless/apm/apm-ui-services.asciidoc

docs/en/observability/apm/view-and-analyze/ui-overview/services.asciidoc

@@ -36,7 +36,7 @@ and enable the **Service groups feature**.
 
 To create a service group:
 
-. Navigate to **Observability** → **Applications** → **Services**.
+. Navigate to **Observability** → **Applications** → **Service inventory**.
 . Switch to **Service groups**.
 . Click **Create group**.
 . Specify a name, color, and description.

docs/en/observability/monitor-k8s/monitor-k8s-application-performance.asciidoc

@@ -210,7 +210,7 @@ kubectl apply -f demo.yml
 [discrete]
 === View your traces in {kib}
 
-To view your application's trace data, open {kib} and go to *{observability} → Services*.
+To view your application's trace data, open {kib} and go to *{observability} → Service inventory*.
 
 The Applications UI allows you to monitor your software services and applications in real-time:
 visualize detailed performance information on your services, identify and analyze errors,

docs/en/serverless/apm/apm-find-transaction-latency-and-failure-correlations.asciidoc

@@ -0,0 +1,99 @@
+[[observability-apm-find-transaction-latency-and-failure-correlations]]
+= Find transaction latency and failure correlations
+
+// :keywords: serverless, observability, how-to
+
+preview:[]
+
+Correlations surface attributes of your data that are potentially correlated
+with high-latency or erroneous transactions. For example, if you are a site
+reliability engineer who is responsible for keeping production systems up and
+running, you want to understand what is causing slow transactions. Identifying
+attributes that are responsible for higher latency transactions can potentially
+point you toward the root cause. You may find a correlation with a particular
+piece of hardware, like a host or pod. Or, perhaps a set of users, based on IP
+address or region, is facing increased latency due to local data center issues.
+
+To find correlations:
+
+. In your {obs-serverless} project, go to **Applications** → **Service Inventory**.
+. Select a service.
+. Select the **Transactions** tab.
+. Select a transaction group in the **Transactions** table.
+
+[NOTE]
+====
+Active queries _are_ applied to correlations.
+====
+
+[discrete]
+[[observability-apm-find-transaction-latency-and-failure-correlations-find-high-transaction-latency-correlations]]
+== Find high transaction latency correlations
+
+The correlations on the **Latency correlations** tab help you discover which
+attributes are contributing to increased transaction latency.
+
+[role="screenshot"]
+image::images/transactions/correlations-hover.png[APM latency correlations]
+
+The progress bar indicates the status of the asynchronous analysis, which
+performs statistical searches across a large number of attributes. For large
+time ranges and services with high transaction throughput, this might take some
+time. To improve performance, reduce the time range.
+
+The latency distribution chart visualizes the overall latency of the
+transactions in the transaction group. If there are attributes that have a
+statistically significant correlation with slow response times, they are listed
+in a table below the chart. The table is sorted by correlation coefficients that
+range from 0 to 1. Attributes with higher correlation values are more likely to
+contribute to high latency transactions. By default, the attribute with the
+highest correlation value is added to the chart. To see the latency distribution
+for other attributes, select their row in the table.
+
+If a correlated attribute seems noteworthy, use the **Filter** quick links:
+
+* `+` creates a new query in the Applications UI for filtering transactions containing
+the selected value.
+* `-` creates a new query in the Applications UI to filter out transactions containing
+the selected value.
+
+You can also click the icon beside the field name to view and filter its most
+popular values.
+
+In this example screenshot, there are transactions that are skewed to the right
+with slower response times than the overall latency distribution. If you select
+the `+` filter in the appropriate row of the table, it creates a new query in
+the Applications UI for transactions with this attribute. With the "noise" now
+filtered out, you can begin viewing sample traces to continue your investigation.
+
+[discrete]
+[[correlations-error-rate]]
+== Find failed transaction correlations
+
+The correlations on the **Failed transaction correlations** tab help you discover
+which attributes are most influential in distinguishing between transaction
+failures and successes. In this context, the success or failure of a transaction
+is determined by its {ecs-ref}/ecs-event.html#field-event-outcome[event.outcome]
+value. For example, APM agents set the `event.outcome` to `failure` when an HTTP
+transaction returns a `5xx` status code.
+
+The chart highlights the failed transactions in the overall latency distribution
+for the transaction group. If there are attributes that have a statistically
+significant correlation with failed transactions, they are listed in a table.
+The table is sorted by scores, which are mapped to high, medium, or low impact
+levels. Attributes with high impact levels are more likely to contribute to
+failed transactions. By default, the attribute with the highest score is added
+to the chart. To see a different attribute in the chart, select its row in the
+table.
+
+For example, in the screenshot below, there are attributes such as a specific
+node and pod name that have medium impact on the failed transactions.
+
+[role="screenshot"]
+image::images/correlations/correlations-failed-transactions.png[Failed transaction correlations]
+
+Select the `+` filter to create a new query in the Applications UI for transactions
+with one or more of these attributes. If you are unfamiliar with a field, click
+the icon beside its name to view its most popular values and optionally filter
+on those values too. Each time that you add another attribute, it is filtering
+out more and more noise and bringing you closer to a diagnosis.

docs/en/serverless/apm/apm-get-started.asciidoc

@@ -0,0 +1,186 @@
+[[observability-apm-get-started]]
+= Get started with traces and APM
+
+// :description: Learn how to collect Application Performance Monitoring (APM) data and visualize it in real time.
+// :keywords: serverless, observability, how-to
+
+preview:[]
+
+:role: Admin
+:goal: send APM data to Elastic
+include::../partials/roles.asciidoc[]
+:role!:
+
+:goal!:
+
+In this guide you'll learn how to collect and send Application Performance Monitoring (APM) data
+to Elastic, then explore and visualize the data in real time.
+
+[discrete]
+[[add-apm-integration-agents]]
+== Step 1: Add data
+
+You'll use APM agents to send APM data from your application to Elastic. Elastic offers APM agents
+written in several languages and supports OpenTelemetry. Which agent you'll use depends on the language used in your service.
+
+To send APM data to Elastic, you must install an APM agent and configure it to send data to
+your project:
+
+. <<observability-create-an-observability-project,Create a new {obs-serverless} project>>, or open an existing one.
+. To install and configure one or more APM agents, do one of following:
++
+** In your Observability project, go to **Add data** → **Monitor my application performance** → **Elastic APM** and follow the prompts.
+** Use the following instructions:
++
+--
+++++
+<div class="tabs" data-tab-group="apm-apm-get-started">
+  <div role="tablist" aria-label="apm-apm-get-started">
+    <button role="tab" aria-selected="true" aria-controls="apm-apm-get-started-go-panel" id="apm-apm-get-started-go-button">
+      Go
+    </button>
+    <button role="tab" aria-selected="false" aria-controls="apm-apm-get-started-java-panel" id="apm-apm-get-started-java-button" tabindex="-1">
+      Java
+    </button>
+    <button role="tab" aria-selected="false" aria-controls="apm-apm-get-started-net-panel" id="apm-apm-get-started-net-button" tabindex="-1">
+      .NET
+    </button>
+    <button role="tab" aria-selected="false" aria-controls="apm-apm-get-started-nodejs-panel" id="apm-apm-get-started-nodejs-button" tabindex="-1">
+      Node.js
+    </button>
+    <button role="tab" aria-selected="false" aria-controls="apm-apm-get-started-php-panel" id="apm-apm-get-started-php-button" tabindex="-1">
+      PHP
+    </button>
+    <button role="tab" aria-selected="false" aria-controls="apm-apm-get-started-python-panel" id="apm-apm-get-started-python-button" tabindex="-1">
+      Python
+    </button>
+    <button role="tab" aria-selected="false" aria-controls="apm-apm-get-started-ruby-panel" id="apm-apm-get-started-ruby-button" tabindex="-1">
+      Ruby
+    </button>
+    <button role="tab" aria-selected="false" aria-controls="apm-apm-get-started-opentelemetry-panel" id="apm-apm-get-started-opentelemetry-button" tabindex="-1">
+      OpenTelemetry
+    </button>
+  </div>
+  <div tabindex="0" role="tabpanel" id="apm-apm-get-started-go-panel" aria-labelledby="apm-apm-get-started-go-button">
+++++
+include::../transclusion/apm/guide/install-agents/go.asciidoc[]
+
+++++
+  </div>
+  <div tabindex="0" role="tabpanel" id="apm-apm-get-started-java-panel" aria-labelledby="apm-apm-get-started-java-button" hidden="">
+++++
+include::../transclusion/apm/guide/install-agents/java.asciidoc[]
+
+++++
+  </div>
+  <div tabindex="0" role="tabpanel" id="apm-apm-get-started-net-panel" aria-labelledby="apm-apm-get-started-net-button" hidden="">
+++++
+include::../transclusion/apm/guide/install-agents/net.asciidoc[]
+
+++++
+  </div>
+  <div tabindex="0" role="tabpanel" id="apm-apm-get-started-nodejs-panel" aria-labelledby="apm-apm-get-started-nodejs-button" hidden="">
+++++
+include::../transclusion/apm/guide/install-agents/node.asciidoc[]
+
+++++
+  </div>
+  <div tabindex="0" role="tabpanel" id="apm-apm-get-started-php-panel" aria-labelledby="apm-apm-get-started-php-button" hidden="">
+++++
+include::../transclusion/apm/guide/install-agents/php.asciidoc[]
+
+++++
+  </div>
+  <div tabindex="0" role="tabpanel" id="apm-apm-get-started-python-panel" aria-labelledby="apm-apm-get-started-python-button" hidden="">
+++++
+include::../transclusion/apm/guide/install-agents/python.asciidoc[]
+
+++++
+  </div>
+  <div tabindex="0" role="tabpanel" id="apm-apm-get-started-ruby-panel" aria-labelledby="apm-apm-get-started-ruby-button" hidden="">
+++++
+include::../transclusion/apm/guide/install-agents/ruby.asciidoc[]
+
+++++
+  </div>
+  <div tabindex="0" role="tabpanel" id="apm-apm-get-started-opentelemetry-panel" aria-labelledby="apm-apm-get-started-opentelemetry-button" hidden="">
+++++
+include::../transclusion/apm/guide/open-telemetry/otel-get-started.asciidoc[]
+
+++++
+  </div>
+</div>
+++++
+--
++
+While there are many configuration options, all APM agents require:
++
+|===
+| Option | Description
+
+| **Service name**
+a| The APM integration maps an instrumented service's name — defined in
+each {apm-agent}'s configuration — to the index where its data is stored.
+Service names are case-insensitive and must be unique.
+
+For example, you cannot have a service named `Foo` and another named `foo`.
+Special characters will be removed from service names and replaced with underscores (`_`).
+
+| **Server URL**
+a| The host and port that the managed intake service listens for events on.
+
+To find the URL for your project:
+
+. Go to the https://cloud.elastic.co/[Cloud console].
+. Next to your project, select **Manage**.
+. Next to _Endpoints_, select **View**.
+. Copy the _APM endpoint_.
+
+| **API key**
+a| Authentication method for communication between {apm-agent} and the managed intake service.
+
+You can create and delete API keys in Applications Settings:
+
+. Go to any page in the _Applications_ section of the main menu.
+. Click **Settings** in the top bar.
+. Go to the **Agent keys** tab.
+
+| **Environment**
+a| The name of the environment this service is deployed in, for example "production" or "staging".
+
+Environments allow you to easily filter data on a global level in the UI.
+It's important to be consistent when naming environments across agents.
+|===
+. If you're using the step-by-step instructions in the UI, after you've installed and configured an agent,
+you can click **Check Agent Status** to verify that the agent is sending data.
+
+To learn more about APM agents, including how to fine-tune how agents send traces to Elastic,
+refer to <<observability-apm-send-data-to-elastic>>.
+
+[discrete]
+[[view-apm-integration-data]]
+== Step 2: View your data
+
+After one or more APM agents are installed and successfully sending data, you can view
+application performance monitoring data in the UI.
+
+In the _Applications_ section of the main menu, select **Service Inventory**.
+This will show a high-level overview of the health and general performance of all your services.
+
+Learn more about visualizing APM data in <<observability-apm-view-and-analyze-traces>>.
+
+// TO DO: ADD SCREENSHOT
+
+[TIP]
+====
+Not seeing any data? Find helpful tips in <<observability-apm-troubleshooting,Troubleshooting>>.
+====
+
+[discrete]
+[[observability-apm-get-started-next-steps]]
+== Next steps
+
+Now that data is streaming into your project, take your investigation to a
+deeper level. Learn how to use <<observability-apm-view-and-analyze-traces,Elastic's built-in visualizations for APM data>>,
+<<observability-alerting,alert on APM data>>,
+or <<observability-apm-send-data-to-elastic,fine-tune how agents send traces to Elastic>>.

docs/en/serverless/apm/apm-ui-services.asciidoc

@@ -0,0 +1,65 @@
+[[observability-apm-services]]
+= Services
+
+// :keywords: serverless, observability, reference
+
+preview:[]
+
+The **Services** inventory provides a quick, high-level overview of the health and general
+performance of all instrumented services.
+
+To help surface potential issues, services are sorted by their health status:
+**critical** → **warning** → **healthy** → **unknown**.
+Health status is powered by <<observability-apm-integrate-with-machine-learning,machine learning>>
+and requires anomaly detection to be enabled.
+
+In addition to health status, active alerts for each service are prominently displayed in the service inventory table. Selecting an active alert badge brings you to the **Alerts** tab where you can learn more about the active alert and take action.
+
+[role="screenshot"]
+image::images/services/apm-services-overview.png[Example view of services table the Applications UI]
+
+[discrete]
+[[observability-apm-services-service-groups]]
+== Service groups
+
+:role: Editor
+:goal: create and manage service groups
+include::../partials/roles.asciidoc[]
+:role!:
+
+:goal!:
+
+:feature: Service grouping
+include::../partials/feature-beta.asciidoc[]
+:feature!:
+
+Group services together to build meaningful views that remove noise, simplify investigations across services,
+and combine related alerts.
+
+// This screenshot is reused in the alerts docs
+
+// Ensure it has an active alert showing
+
+[role="screenshot"]
+image::images/services/apm-service-group.png[Example view of service group in the Applications UI]
+
+To create a service group:
+
+. In your {obs-serverless} project, go to **Applications** → **Service Inventory**.
+. Switch to **Service groups**.
+. Click **Create group**.
+. Specify a name, color, and description.
+. Click **Select services**.
+. Specify a {kibana-ref}/kuery-query.html[Kibana Query Language (KQL)] query to filter services
+by one or more of the following dimensions: `agent.name`, `service.name`, `service.language.name`,
+`service.environment`, `labels.<xyz>`. Services that match the query within the last 24 hours will
+be assigned to the group.
+
+[discrete]
+[[observability-apm-services-examples]]
+=== Examples
+
+Not sure where to get started? Here are some sample queries you can build from:
+
+* **Group services by environment**: To group "production" services, use `service.environment : "production"`.
+* **Group services by name**: To group all services that end in "beat", use `service.name : *beat`. This will match services named "Auditbeat", "Heartbeat", "Filebeat", and so on.