API Monitoring alert is not triggered when target server is down

[nhatminhho1984]

I set up email alert when there is backend server down. Back-end servers are configured in loadbalancer (https://docs.apigee.com/api-platform/deploy/load-balancing-across-backend-servers) using HealthMonitor API but there is no email alert. Anyone knows the reason? Thanks

1. Loadbalancer:

   <HTTPTargetConnection>
           <LoadBalancer>
               <Server name="target1"/>
               <Server name="target2">
                   <IsFallback>true</IsFallback>
               </Server>
               <MaxFailures>2</MaxFailures>
           </LoadBalancer>
           <Path>/json</Path>
           <HealthMonitor>
               <IsEnabled>true</IsEnabled>
               <IntervalInSec>3</IntervalInSec>
               <HTTPMonitor>
                   <Request>
                       <ConnectTimeoutInSec>10</ConnectTimeoutInSec>
                       <SocketReadTimeoutInSec>30</SocketReadTimeoutInSec>
                       <Verb>GET</Verb>
                       <Path>/json</Path>
                   </Request>
                   <SuccessResponse>
                       <ResponseCode>200</ResponseCode>
                   </SuccessResponse>
               </HTTPMonitor>
           </HealthMonitor>
       </HTTPTargetConnection>
   

2. I use API Monitoring to set up alert and use fault code (https://docs.apigee.com/api-monitoring/alerts-notifications):
   Target errors, no active targets
   UI: Gateway > Target > Gateway TargetServerConfiguredInLoadBalancersIsDown Please see the attached picture

[cjking]

What exactly did you do to bring the backend server down for testing?

I see you have two servers configured in your load balancer - did you take them both offline, or just one? I suspect you're going to need to take both offline to get this to fire although I haven't tested it myself.