Symptom

When NDFC attempts status discovery of a device, the "Manage > Inventory" table displays "Session Error(Code 103)" on the device.

Conditions

This should generally recover in most of the scenarios in a few mins, That is when cluster has gone through node outage or certain services experienced a transient failure. In the case where this does not recover, only observed in a very high scale scenario a workaround would be needed. Further investigating the tech-support collected from all nodes, the dcnm-sim-master directory log files indicate following errors occurring repeatedly "Returning error code: 400. Reason: stream error: stream ID 1105807; CANCEL" The Stream ID 1105807 is an example and can be any number that keeps incrementing in each log line.

Workaround

Workaround for this solution is to Navigate to "Admin -> Server Settings -> Debug" and set the log level to "Debug" for "NDFC sim-master service" Save the config and then reset the config back to "Info" after a minute. This causes a particular service that is having the issue to restart and fix itself.

Further Problem Description