Implementation challenges: Errors

[StefanoFalsetto-CKHIOD]

While the definition of the errors is detailed, the error cases are not so clear.

HTTP Error Code	Message	Comments
409 ABORTED	Concurrency conflict.	Which is the error case?
409 ALREADY_EXISTS	The resource that a client tried to create already exists.	Which is the error case?
409 CONFLICT	A specified resource duplicate entry found.	Which is the error case?
415 UNSUPPORTED_MEDIA_TYPE	The server refuses to accept the request because the payload format is in an unsupported format.	Which is the error case?
422 UNIDENTIFIABLE_DEVICE	Phone number not defined.	should this error be raised when there is no phone number in request? The 400 INVALID_ARGUMENT is not correct in that case?

Please help me answering to the questions into the "Comments" column.

[FabrizioMoggio]

These are defined by the CAMARA Guidelines: https://github.com/camaraproject/Commonalities/blob/main/documentation/API-design-guidelines.md

and in: https://github.com/camaraproject/Commonalities/blob/main/artifacts/CAMARA_common.yaml

Let's try to make some more reasoning in the context of the CFS API

[FabrizioMoggio]

According to the Guidelines the Following Error codes must be present:

for POST: 400, 401, 403, 409, 415, 429, 500, 503

So we need 409 and 415

422 instead is used in 3Legs when the variable PhoneNumber differs from the related value in the AccessToken

[StefanoFalsetto-CKHIOD]

Thank you Fabrizio for clarifying to me the 422 Error.

I think the 409 ALREADY_EXISTS and 409 CONFLICT errors are out of scope since there are no resources to create (hence no duplication or conflict).
The 409 ABORTED could be used in case of an MNO is allowing only one request per API consumer per scope per MSISDN. But I think that's a limitation not useful to introduce.

What do you think?

415 error case is still unknown to me. In commonalties it is stated "should not happen"...

[FabrizioMoggio]

About 409, I just commented below. In my understanding we are sharing the same view

[FabrizioMoggio]

About 415, in my understanding it is used when the body is not in JSON format. Am I wrong (I'm not an expert)?

[FabrizioMoggio]

HTTP Error Code	Message	Comments
409 ABORTED	Concurrency conflict.	When the API is invoked by the same API Consumer for the same PhoneNumber and the previous API call is not yet completed. To avoid querying the network if the API Consumer loops.
409 ALREADY_EXISTS	The resource that a client tried to create already exists.	For the CFS API this is as above
409 CONFLICT	A specified resource duplicate entry found.	For the CFS API I don't see this happening
415 UNSUPPORTED_MEDIA_TYPE	The server refuses to accept the request because the payload format is in an unsupported format.	Which is the error case?
422 UNIDENTIFIABLE_DEVICE	Phone number not defined.	should this error be raised when there is no phone number in request? The 400 INVALID_ARGUMENT is not correct in that case?

[FabrizioMoggio]

Anyway for 409 these are examples provided by the guidelines. Maybe we can delete some of those examples if not coherent with the CFS API (ALREADY_EXISTS, CONFLICT).

[StefanoFalsetto-CKHIOD]

I agree with you, I think at the moment we can remove the 409 from the specs.

[FabrizioMoggio]

one clarification. We can not remove 409, it is mandatory according to the Guideline, but we can just keep 409 ABORTED, removing the other ones. Is this possible?

[StefanoFalsetto-CKHIOD]

We can keep it in specifications but I think in our implementation we will never raise this error.

[FabrizioMoggio]

New Issue: #112

[bigludo7]

Hello
409 we can do what we want :)
For me fine to remove 409.

For the other rror, here the sum-up:
Mandatory Errors to be documented in CAMARA API Spec YAML:

Error status 401
Error status 403
Error status 429 TOO_MANY_REQUESTS (For rate limit control)

Errors not needed to be documented:

405 METHOD_NOT_ALLOWED
406 NOT_ACCEPTABLE
415 UNSUPPORTED_MEDIA_TYPE
5xx errors

[FabrizioMoggio]

Let's remove 409.

[FabrizioMoggio]

@StefanoFalsetto-CKHIOD considering that many errors are no more mandatory we could remove some of them if not useful to our API. I would like to be coherent with your implementation and experience so, can you please identify the list of error you suggest to remove?

[StefanoFalsetto-CKHIOD]

@FabrizioMoggio this is a table with errors we defined as out of scope, and some notes:

Scenario	Error	Note
Inconsistent device	{   "status": 422,   "code": "DEVICE_IDENTIFIERS_MISMATCH",   "message": "Provided device identifiers are not consistent." }	There is it only one identifier.
Concurrency	{   "status": 409,   "code": "ABORTED",   "message": "Concurrency conflict." }	CKH is not using request queue. All the API Calls can be performed in parallel.
Conflict	{   "status": 409,   "code": "CONFLICT",   "message": "A specified resource duplicate entry found" }	This kind of service does not have specific state to be in conflict.
Already exists	{   "status": 409,   "code": "ALREADY_EXISTS",   "message": "The resource that a client tried to create already exists" }	This kind of service does not create resources on server.
Unsupported media type	{   "status": 415,   "code": "UNSUPPORTED_MEDIA_TYPE",   "message": "The server refuses to accept the request because the payload format is in an unsupported format." }	CKH is not able to reproduce the problem. The description in commonalties is: Payload format of the request is in an unsupported format by the Server. Should not happen

Actually, CKH not implemented other errors, depending on specific implementation (e.g., 501, not implemented)

[FabrizioMoggio]

here is a list of actions to be taken: https://lf-camaraproject.atlassian.net/wiki/spaces/CAM/pages/51413132/Analysis+of+Commonalities+0.5.0-alpha.1+changes#Analysis

[FabrizioMoggio]

• On 422 there are new guidelines (already implemented in the current version for Spring25). ok to remove DEVICE_IDENTIFIERS_MISMATCH
• As already agreed, ok to remove 409
• ok to remove 415

[FabrizioMoggio]

Implemented