Symptoms

After a microservice has been successfully upgraded, its apsinstance 'Component status' changed to status  'APS Instance upgrade failed' and 'Deployment status' to 'Deployment failures'.

In a8n-operator log it shows that the corresponding instance on APS is in APS_INSTANCE_UPGRADE_ERROR:

Instance with error on APS, state APS_INSTANCE_UPGRADE_ERROR, you need to apply a manual fix. 

The corresponding task with name 'Upgrading resources of application 'name of app/microservice''on Task Manager level failed with error:

...
'500 Internal Server Error' received from 'POST https://appstore:8081/rest/application/8be9e554-93f9-4a3c-bd24-b94621960cd0/upgrade?version=<current-version-number>': I/O error on GET request for "https://jira.int.zone/rest/api/2/search": Connect to jira.int.zone:443 [jira.int.zone/137.117.182.241] failed: Connection timed out; nested exception is org.apache.http.conn.ConnectTimeoutException: Connect to jira.int.zone:443 [jira.int.zone/137.117.182.241] failed: Connection timed out
...

Cause

The https://jira.int.zone is not whitelisted in the aks cluster.

Resolution

Add https://jira.int.zone in the aks cluster whitelist.