SAP API Management - Spike Arrest - Flow Variables

Scenario: In this exercise, we will see how to use flow variables.

Steps:

1. Add an instance of Spike Arrest in Preflow for incoming request.

2. Modify the code as per requirement.

Code ( 2pm means in each 30 secs, only one call will be allowed)

<!-- This policy throttles the number of requests processed by an API Proxy protecting against performance lags and downtime -->

<SpikeArrest async="true" continueOnError="true" enabled="true" xmlns="http://www.sap.com/apimgmt">

<Rate>2pm</Rate>

<UseEffectiveCount>true</UseEffectiveCount>

</SpikeArrest>

3. Add an instance of Assign Message in Preflow for Outgoing Response.

4. Modify the code as per requirement.

<!-- This policy can be used to create or modify the standard HTTP request and response messages -->

<AssignMessage async="false" continueOnError="false" enabled="true" xmlns='http://www.sap.com/apimgmt'>

 

<!-- Sets a new value to the existing parameter -->

<Set>

<Payload contentType="application/json" variablePrefix="@" variableSuffix="#">

    {

       Spike Triggered?: "@ratelimit.spikeArrest.failed#" }

</Payload>

</Set>

<IgnoreUnresolvedVariables>false</IgnoreUnresolvedVariables>

<AssignTo createNew="false" type="response">response</AssignTo>

</AssignMessage>

5. Test the API.