Using Service call out policy If the backend server is down show the response that is coming from the backend in the console.

Google Cloud Apigee
1

Hello,

I used Service Callout policy to call the service. whenever the server is down of that particular

service Then I have to show the response that is coming from the backend in the console.

Could any one please help me?

2

Hi @NAVAJEEVANA BATHULA

Welcome to the community !!!

Not sure I understand the issue. Can you detail a bit more ?

What I understood is - you are making a Service callout and if that system is down, you want to send the request to another target system ? Is that correct ? Not sure what you mean by “show the response that is coming from the backend in the console”

3

You could return a previously cached version of the response if the risk of stale data isn’t high for your use case?

4

@NAVAJEEVANA BATHULA, As per my understanding you want to display the back end error message as-is on the front end. Follow the below mentioned steps to achieve it.

  1. Define FaultRule for “ExecutionFailed” fault to capture the back end error response.
<FaultRule name="ExecutionFailed">
            <Step>
                <Name>AM-Set-Execution-Failed-Error</Name>
            </Step>
            <Condition>(fault.name == "ExecutionFailed") or (fault.name == "servicecallout.ExecutionFailed")</Condition>
        </FaultRule>
  1. Define an AssignMessage policy to set the “ServiceCallout.response” as payload with appropriate contentType.
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<AssignMessage name="AM-Set-Execution-Failed-Error" enabled="true" continueOnError="false" async="false">
    <DisplayName>AM-Set-Execution-Failed-Error</DisplayName>
    <Set>
        <Headers/>
        <Payload contentType="application/json">{ServiceCallout.response}</Payload>
        <StatusCode>{response.status.code}</StatusCode>
    </Set>
    <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
    <AssignTo type="request" transport="http" createNew="false"/>
</AssignMessage>
5

Thanks for your response Mahammad Feroz. when the server is up I am getting response for ServiceCallout.response but if the server is down ServiceCallout.response is showing null. it is not returning any value. Is there anyting we could with this.

6

@NAVAJEEVANA BATHULA

, use “error.content” instead of “ServiceCallout.response” in the AssignMessage (AM-Set-Execution-Failed-Error) policy.