Normalize AWS RDS CPU Utilization values before metadata API call (#3…

…9664)

* handle cpu normalization before the API call

* add changelog entry

* fix changelog pr id

CHANGELOG.next.asciidoc

@@ -170,6 +170,7 @@ https://github.com/elastic/beats/compare/v8.8.1\...main[Check the HEAD diff]
 - Fix timeout caused by the retrival of which indices are hidden {pull}39165[39165]
 - Fix Azure Monitor support for multiple aggregation types {issue}39192[39192] {pull}39204[39204]
 - Fix for MySQL/Performance - Query failure for MySQL versions below v8.0.1, for performance metric `quantile_95`. {pull}38710[38710]
+- Normalize AWS RDS CPU Utilization values before making the metadata API call. {pull}39664[39664]
 
 *Osquerybeat*
 

x-pack/metricbeat/module/aws/cloudwatch/metadata/rds/rds.go

@@ -27,12 +27,9 @@ func AddMetadata(regionName string, awsConfig awssdk.Config, fips_enabled bool,
 		}
 	})
 
-	// Get DBInstance IDs per region
-	dbDetailsMap, err := getDBInstancesPerRegion(svc)
-	if err != nil {
-		return events, fmt.Errorf("aws.rds.db_instance fields are not available, skipping region %s: %w", regionName, err)
-	}
-
+	// Normalize CPU Utilization values before making the API call,
+	// because the API call can fail, and we need to ensure the
+	// CPU values are correctly scaled regardless of the API call outcome.
 	for _, event := range events {
 		cpuValue, err := event.RootFields.GetValue("aws.rds.metrics.CPUUtilization.avg")
 		if err == nil {
@@ -42,6 +39,12 @@ func AddMetadata(regionName string, awsConfig awssdk.Config, fips_enabled bool,
 		}
 	}
 
+	// Get DBInstance IDs per region
+	dbDetailsMap, err := getDBInstancesPerRegion(svc)
+	if err != nil {
+		return events, fmt.Errorf("aws.rds.db_instance fields are not available, skipping region %s: %w", regionName, err)
+	}
+
 	for dbInstanceIdentifier, output := range dbDetailsMap {
 		for eventIdentifier := range events {
 			eventIdentifierComponents := strings.Split(eventIdentifier, "-")