When unique constraint error occured, exception of NovaBase.save() raising cause is sqlalchemy.exc.IntegrityError.

[ryuta sekine]

Now, when unique constraint error occured, sqlalchemy.exc.IntegrityError is raised without entering through the else branch if statement.
Exception eventually receive nova.exception.DBError, because it is rapped in get_session() of nova/db/sqlalchemy/session.py

def save(self, session=None):
    """Save this object."""
    if not session:
        session = get_session()
    session.add(self)
    try:
        session.flush()
    except IntegrityError, e:
        if str(e).endswith('is not unique'):
            raise exception.Duplicate(str(e))
        else:
            raise

[error log]

======================================================================
FAIL: test_session_flush_on_integrity_violation()
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/opt/stack/tempest/tempest/manual_tests/negative_st/test_negative_sqlalchemy.py", line 159, in test_session_flush_on_integrity_violation
    self.assertEqual(exception.Duplicate, inner_ex.__class__)
AssertionError: <class 'nova.exception.Duplicate'> != <class 'sqlalchemy.exc.IntegrityError'>
-------------------- >> begin captured logging << --------------------
tempest.config: INFO: Using tempest config file /opt/stack/tempest/etc/tempest.conf
nova.exception: ERROR: DB exception wrapped.
Traceback (most recent call last):
  File "/opt/stack/nova/nova/exception.py", line 68, in _wrap
    return f(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 1547, in flush
    self._flush(objects)
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 1616, in _flush
    flush_context.execute()
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/unitofwork.py", line 328, in execute
    rec.execute(self)
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/unitofwork.py", line 472, in execute
    uow
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/mapper.py", line 2264, in _save_obj
    execute(statement, multiparams)
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1405, in execute
    params)
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1538, in _execute_clauseelement
    compiled_sql, distilled_params
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1646, in _execute_context
    context)
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1639, in _execute_context
    context)
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 330, in do_execute
    cursor.execute(statement, parameters)
  File "/usr/lib/python2.7/dist-packages/MySQLdb/cursors.py", line 174, in execute
    self.errorhandler(self, exc, value)
  File "/usr/lib/python2.7/dist-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
IntegrityError: (IntegrityError) (1062, "Duplicate entry '9' for key 'PRIMARY'") 'INSERT INTO services (created_at,
updated_at, deleted_at, deleted, id, host, `binary`, topic, report_count, disabled, availability_zone) VALUES (%s,
%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)' (datetime.datetime(2012, 9, 13, 2, 16, 22, 105645), None, None, 0, 9L,
None, None, None, 0, 0, 'nova')

Reason of bug seems to be to coming out of sqlarchemy error without being rapped in a nova.
I think should return nova.exception.Duplicate.

[Chuck Short (zulcss)]

Which version is this with?

[ryuta sekine (r-sekine)]

master and stable/folsom
https://github.com/openstack/nova/blob/stable/folsom/nova/db/sqlalchemy/models.py

[Vish Ishaya (vishvananda)]

This was fixed in master:

https://review.openstack.org/#/c/16339/

needs a backport.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/folsom
Review: https://review.openstack.org/23051