Comment 5 for bug 1882804

Another scenario proposed by Rodolfo (ralonsoh), is to do placement call for update allocations (PUT /allocations/{consumer_uuid} ) before the db transaction begins for port update (BEFORE_UPDATE callback for Port).

Pros:
* no change in current Port update API (synchronous behaviour, when the API returns the user can expect that all operations arefinished)
* the possibly time consuming REST call for placement is outside (before) db transaction.
* as nothing is written to the DB in case of failure there is no need for rollback.

Cons:
* in case there is a need to update allocations in placement the user can experience extra time cost for port update (this is anyway true)