Turn on disable APM stats in the Datadog Exporter feature gate by def…

…ault (open-telemetry#31219)

**Description:** <Describe what has changed.>
<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->

Changes noAPMStatsFeatureGate to beta in order to disable APM stats in
the exporter by default

**Link to tracking Issue:** <Issue number if applicable>

**Testing:** <Describe what testing was performed and which tests were
added.>

**Documentation:** <Describe the documentation added.>

---------

Co-authored-by: Pablo Baeyens <[email protected]>

.chloggen/stanley.liu_enable-no-apms-stats-feature-gate.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: breaking
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: exporter/datadogexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Disable APM stats computation in Datadog Exporter by default, `exporter.datadogexporter.DisableAPMStats` is changed to beta
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [31219]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

exporter/datadogexporter/README.md

@@ -19,6 +19,9 @@
 
 > Please review the Collector's [security documentation](https://github.com/open-telemetry/opentelemetry-collector/blob/main/docs/security-best-practices.md), which contains recommendations on securing sensitive information such as the API key required by this exporter.
 
+> The Datadog Exporter now skips APM stats computation by default. It is recommended to only use the [Datadog Connector](https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/connector/datadogconnector) in order to compute APM stats.
+> To temporarily revert to the previous behavior, disable the `exporter.datadogexporter.DisableAPMStats"` feature gate. Example: `otelcol --config=config.yaml --feature-gates=-exporter.datadogexporter.DisableAPMStats"`
+
 Visit the [official documentation](https://docs.datadoghq.com/tracing/trace_collection/open_standards/otel_collector_datadog_exporter/) for usage instructions.
 
 ## FAQs

exporter/datadogexporter/factory.go

@@ -47,7 +47,7 @@ var metricExportNativeClientFeatureGate = featuregate.GlobalRegistry().MustRegis
 // noAPMStatsFeatureGate causes the trace consumer to skip APM stats computation.
 var noAPMStatsFeatureGate = featuregate.GlobalRegistry().MustRegister(
 	"exporter.datadogexporter.DisableAPMStats",
-	featuregate.StageAlpha,
+	featuregate.StageBeta,
 	featuregate.WithRegisterDescription("Datadog Exporter will not compute APM Stats"),
 )