AX 2012 R3 AOS Service Principal Name (SPN)

March 26 2015 - please also read my Update on this subject.

After working my way through both a new installation and upgrades from AX 2012 R2 (CU7), I find at least one glitch that 1) logs an Error in Event Log - Application when stopping and starting the AOS Service  and 2) that possibly increases the time to start the AOS Service.

I notice the following events beeing logged:

• Start of AOS Service > Object Server 01:  RPC error: Failed to register service principal name (SPN): '<GUID>/<server>.<FQDN>:<AOS RPC Port#>' 
• Stop of AOS Service > Object Server 01:  RPC error: Failed to unregister service principal name (SPN): <GUID>/<server>.<FQDN>:<AOS RPC Port#>' 

This seems to be related to utilizing Managed Service Accounts (an option when specifying the AOS Service Account) or not, where it seems like the AOS Service operates like it's always hosted by a Managed Service Account. In all installations I have used "Use the following account" and not the "Use a managed service account", but despite this deliberate choice, the messages are beeing logged.

Maybe it's difficult or even impossible to separate the different types of Service Accounts, but it should be possible to have this as a property for the Service (registry). The time it takes to start the AOS Service seems to increase in each release of AX 2012 due to the increased number of processes the AOS Service must handle and possible time consuming tasks like this, should indeed be avoided.

Bottom line - I'm supprised to see SPN errors beeing logged like this even when not utilizing a Managed Service Account (which requires a SPN and new requirements regarding integration to objecst in Active Directory).