Rate limiter documentation

docs/user-guide/api-mediation/configuration-customizing-management-of-apiml-load-limits.md

@@ -8,6 +8,10 @@ As a system programmer, you can customize your configuration for how API ML mana
  * To change the number of concurrent connections per route passing through the API Gateway, see [Customizing connection limits](./configuration-connection-limits.md).
 
  * To change the global Gateway timeout value for the API ML instance, see [Customizing Gateway timeouts](./configuration-gateway-timeouts.md).
+
+ * To change the number of concurrent requests an application should support and its impact on the size of the Java memory heap, see [Customizing Java Heap sizes](./configuration-customizing-java-heap-sizes.md).
+
+ * To customize the rate limit for each service, see [Customizing Gateway rate limiter](./customizing-gateway-rate-limiter.md).
 
  * Also see the following properties in API Gateway configuration parameters: 
     * `server.maxTotalConnections`

docs/user-guide/api-mediation/customizing-gateway-rate-limiter.md

@@ -0,0 +1,36 @@
+# Customizing Gateway rate limiter
+
+:::info Role: system programmer
+:::
+
+The API Gateway offers a way to customize the rate limit for each service via a configurable rate limiter, which prevents individual users from overloading the system with excessive requests.  Configuring the rate limiter helps ensure that a user's activity does not negatively impact the experience of other users by mitigating the risk of Distributed Denial-of-Service (DDoS) attacks and other automated exploit attempts. 
+
+Use the following procedure to customize the Gateway rate limiter:
+
+1. In the zowe.yaml, set the following rate limiting properties in api/gateway/routing:
+
+   * **rateLimiterCapacity**  
+  Defines the total number of requests that can be allowed at one time per user.
+
+   * **rateLimiterTokens**  
+  Defines the number of requests that are added to the service’s allowance at regular intervals. This property controls how quickly requests are replenished after being consumed.
+
+   * **rateLimiterRefillDuration**  
+  Sets the time interval (in minutes) at which new requests (or tokens) are added.
+
+2. Define the services to limit:
+
+   Use `servicesToLimitRequestRate` to specify a list of services to limit. In the following example, this property applies to the API Catalog. 
+
+**Example configuration:**
+```
+    apiml:
+        gateway: 
+            routing: 
+                rateLimiterCapacity: 20
+                rateLimiterTokens: 20
+                rateLimiterRefillDuration: 1
+                servicesToLimitRequestRate: apicatalog
+```
+You configured the properties of the rate limiter for the API Catalog, thereby improving user accessibility and overall system stability. 
+

sidebars.js

@@ -286,6 +286,7 @@ module.exports = {
                   "items": [
                     "user-guide/api-mediation/configuration-connection-limits",
                     "user-guide/api-mediation/configuration-gateway-timeouts",
+                    "user-guide/api-mediation/customizing-gateway-rate-limiter",
                     "user-guide/api-mediation/configuration-customizing-java-heap-sizes"
                   ]
 	              }