Open Stack

Mike Bayer <mbayer at redhat.com> wrote:

> We need to decide how to handle this:
>
> https://review.openstack.org/#/c/362991/
>
>
> Basically, PyMySQL normally raises an error message like this:
>
> (pymysql.err.IntegrityError) (1452, u'Cannot add or update a child row: a  
> foreign key constraint fails (`vaceciqnzs`.`resource_entity`, CONSTRAINT  
> `foo_fkey` FOREIGN KEY (`foo_id`) REFERENCES `resource_foo` (`id`))')
>
> for some reason, PyMySQL 0.7.7 is now raising it like this:
>
> (pymysql.err.IntegrityError) (1452, u'23000Cannot add or update a child  
> row: a foreign key constraint fails (`vaceciqnzs`.`resource_entity`,  
> CONSTRAINT `foo_fkey` FOREIGN KEY (`foo_id`) REFERENCES `resource_foo`  
> (`id`))')
>
> this impacts oslo.db's "exception re-handling" functionality which tries  
> to classify this exception as a DBNonExistentConstraint exception.   It  
> also breaks oslo.db's test suite locally, but in a downstream project  
> would only impact its ability to intercept this exception appropriately.
>
> now that "23000" there looks like a bug.  The above gerrit proposes to  
> work around it.  However, if we didn't push out the above gerrit, we'd  
> instead have to change requirements:
>
> https://review.openstack.org/#/q/I33d5ef8f35747d3b6d3bc0bd4972ce3b7fd60371,n,z
>
> It seems like at least one or the other would be needed for Newton.

Unless we fix the bug in next pymysql, it’s not either/or but both will be  
needed, and also minimal oslo.db version bump.

I suggest we:
- block 0.7.7 to unblock upper-constraints updates;
- land oslo.db fix to cope with pymysql 0.7.7+, in master as well as all  
stable branches;
- release new oslo.db releases for L-N;
- at least for N, bump minimal version of the library in  
global-requirements.txt;
- sync the bump to all consuming projects;
- later, maybe unblock 0.7.7.

In the meantime, interested parties may work with pymysql folks to get the  
issue fixed. It may take a while, so I would not make this step part of our  
short term plan.

Now, I understand that this does not really sound ideal, but I assume we  
are not in requirements freeze yet (the deadline for that is tomorrow), and  
this plan will solve the issue for users of all versions of pymysql.

Ihar