All Services in this Service Set for Servers that support auditing may generate audit entries and shall generate audit Events for both successful and failed Service invocations. These Services shall generate an audit Event of type AuditSessionEventType or a subtype of it. In particular, they shall generate the base EventType or the appropriate subtype, depending on the service that was invoked. The CreateSession service shall generate AuditCreateSessionEventType events or sub-types of it. The ActivateSession service shall generate AuditActivateSessionEventType events or subtypes of it. When the ActivateSession Service is called to change the user identity then the Server shall generate AuditActivateSessionEventType events or subtypes of it. The CloseSession service shall generate AuditSessionEventType events or subtypes of it. It shall always be generated if a Session is terminated like Session timeout expiration or Server shutdown. The SourceName for Events of this type shall be “Session/Timeout” for a Session timeout, “Session/CloseSession” for a CloseSession Service call and “Session/Terminated” for all other cases. See OPC 10000-5 for the detailed assignment of the SourceNode, the SourceName and additional parameters. For the failure case the Message for Events of this type should include a description of why the Service failed. The additional parameters should include the details of the request.
This Service Set shall also generate additional audit events in the cases when Certificate validation errors occur. These audit Events are generated in addition to the AuditSessionEventType Events. See OPC 10000-3 for the definition of AuditCertificateEventType and its subtypes.
For Clients, that support auditing, accessing the services in the Session Service Set shall generate audit entries for both successful and failed invocations of the Service. These audit entries should be setup prior to the actual Service invocation, allowing the invocation to contain the correct audit record id.