# NServiceBus Host Upgrade Version 4 to 5


## Roles are obsolete

In NServiceBus.Host version 5 and above, roles are obsolete and should not be used. The functionality of `AsA_Server`, and `AsA_Publisher` is now the default and can be safely removed. Read the [Host guidance on alternatives for using roles](/nservicebus/hosting/nservicebus-host/index.md#roles-built-in-configurations).