added brief rate limit information to K8s production guidance for self-hosted gateway

Author: dlepow

articles/api-management/how-to-self-hosted-gateway-on-kubernetes-in-production.md

@@ -7,7 +7,7 @@ ms.service: api-management
 ms.workload: mobile
 ms.topic: article
 ms.author: tomkerkhove
-ms.date: 12/17/2021
+ms.date: 01/17/2023
 ---
 
 # Guidance for running self-hosted gateway on Kubernetes in production
@@ -195,6 +195,18 @@ securityContext:
 > [!WARNING]
 > When using local CA certificates, the self-hosted gateway must run with user ID (UID) `1001` in order to manage the CA certificates otherwise the gateway will not start up.
 
+## Request throttling
+
+Request throttling in a self-hosted gateway can be enabled by using the API Management [rate-limit](rate-limit-policy.md) or [rate-limit-by-key](rate-limit-by-key-policy.md) policy. Configure rate limit counts to synchronize locally (among gateway instances across cluster nodes) by exposing the following ports in the Kubernetes deployment for instance discovery:
+
+* Port 4290 (UDP), for the rate limiting synchronization
+* Port 4291 (UDP), for sending heartbeats to other instances
+
+Configure these settings, for example, using the default [Helm chart deployment](how-to-deploy-self-hosted-gateway-kubernetes-helm.md) for Kubernetes or using the Azure portal [deployment templates](../articles/api-management/how-to-deploy-self-hosted-gateway-kubernetes.md).
+
+> [!NOTE]
+> Rate limit counts don't synchronize with other gateways, including the managed gateway in the cloud.
+
 ## Next steps
 
 * To learn more about the self-hosted gateway, see [Self-hosted gateway overview](self-hosted-gateway-overview.md).

includes/api-management-self-hosted-gateway-rate-limit.md

@@ -2,7 +2,7 @@
 author: dlepow
 ms.service: api-management
 ms.topic: include
-ms.date: 01/11/2023
+ms.date: 01/17/2023
 ms.author: danlep
 ---
-Rate limit counts in a self-hosted gateway can be configured to synchronize locally (among gateway instances across cluster nodes), for example, through [Helm chart deployment](../articles/api-management/how-to-deploy-self-hosted-gateway-kubernetes-helm.md) for Kubernetes or using the Azure Portal [deployment templates](../articles/api-management/how-to-deploy-self-hosted-gateway-kubernetes.md). However, rate limit counts don't synchronize with other gateways, including the managed gateway in the cloud.
+Rate limit counts in a self-hosted gateway can be configured to synchronize locally (among gateway instances across cluster nodes), for example, through Helm chart deployment for Kubernetes or using the Azure portal [deployment templates](../articles/api-management/how-to-deploy-self-hosted-gateway-kubernetes.md). However, rate limit counts don't synchronize with other gateways, including the managed gateway in the cloud. [Learn more](../articles/api-management/how-to-self-hosted-gateway-on-kubernetes-in-production.md#request-throttling)