AccessToken generation with AuthorizationCode in sync by multiple MPs

[#1]

Hi Team,

I have a question from customer on OAuth Token API design.

They will use AuthorizationCode grant_type.
So first API call is a request to get AuthorizationCode and it's followed by generating Access Token with using it.

The question is about a generated AuthorizationCode can be used more than one time.

By RFC it's specified as a single use as follows.

10.5.  Authorization Codes

 Authorization codes MUST be short lived and single-use.  If the
   authorization server observes multiple attempts to exchange an
   authorization code for an access token, the authorization server
   SHOULD attempt to revoke all access tokens already granted based on
   the compromised authorization code.

However as they observed, the AuthorizationCode can be used twice and to get distinctive Access Tokens are given and both are valid. So, it's not follow the above RFC spec.

We guess that if there are multiple MPs, it seems that sync between MPs is not in time when the two requests of generating AccessToken comes to different MP simultaneously.

If this is the case, is there any way to prevent this by enforcing API request for generating AuthorizationCode and AccessToken by a single session on the same MP or sync MP before generating AccessToken on the two MPs?

I would appreciate your help on this query.

Regards,
Toshi