include file

Author: gitName

articles/api-management/emit-metric-policy.md

@@ -17,9 +17,6 @@ ms.custom: engagement-fy23
 
 The `emit-metric` policy sends custom metrics in the specified format to Application Insights.
 
-> [!NOTE]
-> Custom metrics are a [preview feature](/azure/azure-monitor/essentials/metrics-custom-overview) of Azure Monitor and subject to [limitations](/azure/azure-monitor/essentials/metrics-custom-overview#design-limitations-and-considerations).
-
 [!INCLUDE [api-management-policy-generic-alert](../../includes/api-management-policy-generic-alert.md)]
 
 ## Limits for custom metrics

includes/api-management-custom-metrics-limits.md

@@ -0,0 +1,18 @@
+---
+ms.service: azure-api-management
+ms.topic: include
+author: dlepow
+ms.author: danlep
+ms.date: 09/25/2024
+ms.custom: 
+---
+
+Azure Monitor imposes [usage limits](/azure/azure-monitor/essentials/metrics-custom-overview#quotas-and-limits) for custom metrics that may affect your ability to emit metrics from API Management. For example, Azure Monitor currently sets a limit of 10 dimension keys per metric, and a limit of 50,000 total active time series per region in a subscription (within a 12 hour period). 
+
+These limits have the following implications for configuring custom metrics in an API Management policy such as `emit-metric` or `azure-openai-emit-token-metric`:
+
+* You can configure a maximum of 10 custom dimensions per policy.
+
+* The number of active time series generated by the policy within a 12 hour period is the product of the number of unique values of each configured dimension during the period. For example, if three custom dimensions were configured in the policy, and each dimension had 10 possible values within the period, the policy would contribute 1,000 (10 x 10 x 10) active time series.
+
+* If you configure the policy in multiple API Management instances that are in the same region in a subscription, all instances can contribute to the regional active time series limit.