Engage a new Throttling Policy at Runtime

The steps below show how to engage a throttling policy to an API at runtime.

1. Write a new throttling policy. For example, the following sample throttling policy points to a backend service and allows 1000 concurrent requests to a service.

   <wsp:Policy xmlns:wsp="http://schemas.xmlsoap.org/ws/2004/09/policy" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd" xmlns:throttle="http://www.wso2.org/products/wso2commons/throttle" wsu:Id="WSO2MediatorThrottlingPolicy"> <throttle:MediatorThrottleAssertion> <throttle:MaximumConcurrentAccess>1000</throttle:MaximumConcurrentAccess> <wsp:Policy> <throttle:ID throttle:type="IP">other</throttle:ID> </wsp:Policy> </throttle:MediatorThrottleAssertion> </wsp:Policy>

2. Log in to the API Manager's management console ( https://localhost:9443/carbon ) and click the Resource > Browse menu to view the registry.
   

   Open

   

3. Click the /_system/goverence/apimgt/applicationdata path to go to its detailed view.
   

   
   

4. In the detail view, click the Add Resource link.
   

5. Upload the policy file to the server as a registry resource.

6. In the management console, select the Service Bus > Source View menu.
   

7. The configurations of all APIs created in the API Manager instance opens. To engage the policy to a selected API, add it to your API definition. In this example, we add it to the login API.

   <api xmlns="http://ws.apache.org/ns/synapse" name="_WSO2AMLoginAPI_" context="/login"> <resource methods="POST" url-mapping="/*"> <inSequence> <send> <endpoint> <address uri="https://localhost:9493/oauth2/token"/> </endpoint> </send> </inSequence> <outSequence> <send/> </outSequence> </resource> <handlers> <handler class="org.wso2.carbon.apimgt.gateway.handlers.throttling.APIThrottleHandler"> <property name="id" value="A"/> <property name="policyKey" value="gov:/apimgt/applicationdata/throttle.xml"/> </handler> <handler class="org.wso2.carbon.apimgt.gateway.handlers.ext.APIManagerExtensionHandler"/> </handlers> </api>

You have successfully engaged a throttling policy to an API at runtime, without restarting the server.