Symptom

vManage Server is not ready or temporarily unavailable after upgrade to release 20.6.4 or higher.

Conditions

Workaround

Restart both the application-server and configuration-db to clear a stuck thread condition.

Further Problem Description

To verify the vManage deeper, we should take thread dump to verify whether we do indeed have stuck thread as follows : 1. request nms application-server jcmd thread-print | save /var/log/nms/Thread1.log 2. wait 10 min 3. request nms application-server jcmd thread-print | save /var/log/nms/Thread2.log (Note: Filename must be different to previous one) 4. Take admin-tech and attach to SR