Internal IDs are not atomic
The code for generating internal IDs (iids) is as follows:
def set_iid if iid.blank? records = project.send(self.class.name.tableize) records = records.with_deleted if self.paranoid? max_iid = records.maximum(:iid) self.iid = max_iid.to_i + 1 end end
This code is not atomic, meaning it's possible for 2 issues trying to use the same iid. This will lead to a unique constraint failure, resulting in errors showing up to a user. We're seeing this in our PostgreSQL logs in the form of:
ERROR: duplicate key value violations - unique constraint "index_issues_on_project_id_and_iid"
This method should be made atomic somehow, or the issue creation process should retry in case of unique constraints.