GetMetrics API Invocation count in certain error cases

Question

These questions refer to the invocation count maintained for the GetMetrics API.

If an authenticated high tier API like GetAccounts responds back with 404 Not Found and 405 Not Allowed, then are these requests counted as valid invocations?

If yes, then where is the count captured, in the authenticated section or in the unattended section?

Examples:
GET/banking/account: Response for 404 (resources not found due to missing  in the URL)
DELETE/banking/accounts: Response for 405

Do the above need to be counted in GetMetrics?

Answer

Both examples describe an invalid resource request.

• A 405 error implies an invalid method is attempted against a resource. Because the combination of method and resource do not exist, there is no invocation from the CDS perspective.
• A 404 error, resulting from an invalid (permanently unavailable or unknown) resource, is not an invocation. Because the resource does not exist, there is no invocation from the CDS perspective. 
• A 404 error, due to a temporarily unavailable account, is considered an invocation.

If the error is related to a known resource and an error such as 400 is raised, this is considered an invocation of the API.