| 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 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). In API Management, 5 of these are used for default dimensions including the following:
- Region
- Service ID
- Service Name
- Service Type
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 5 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.
Learn more about design limitations and considerations for custom metrics in Azure Monitor.