openstack/deb-python-oslo.db
Code Issues Proposed changes

Ensure create_engine() retries the initial connection test

Browse Source 
Before return create_engine() tests the connectivity to a DB. At this
moment a DB might be unavailable for some reason, in which case
create_engine() retries a few times. When used with MySQL, we didn't
actually retry, but instead failed on the first connectivity error
when trying to get the value of sql_mode session variable.

Closes-Bug: #1376211

Co-Authored-By: Mike Bayer <mike_mp@zzzcomputing.com>
Change-Id: I14e25cfe1ed51b0d51a94e491b7267f26e42d34e
This commit is contained in:
Roman Podoliaka 2014-10-01 16:10:20 +03:00
parent 26ec2fcaa2
commit 01a54cc5cc
2 changed files with 46 additions and 21 deletions
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34
oslo/db/sqlalchemy/session.py
View File

@ -466,19 +466,27 @@ def _init_events(engine, mysql_sql_mode=None, **kw):
cursor = dbapi_con.cursor()
cursor.execute("SET SESSION sql_mode = %s", [mysql_sql_mode])
realmode = engine.execute("SHOW VARIABLES LIKE 'sql_mode'").fetchone()
if realmode is None:
LOG.warning(_LW('Unable to detect effective SQL mode'))
else:
realmode = realmode[1]
LOG.debug('MySQL server mode set to %s', realmode)
if 'TRADITIONAL' not in realmode.upper() and \
'STRICT_ALL_TABLES' not in realmode.upper():
LOG.warning(
_LW(
"MySQL SQL mode is '%s', "
"consider enabling TRADITIONAL or STRICT_ALL_TABLES"),
realmode)
@sqlalchemy.event.listens_for(engine, "first_connect")
def _check_effective_sql_mode(dbapi_con, connection_rec):
if mysql_sql_mode is not None:
_set_session_sql_mode(dbapi_con, connection_rec)
cursor = dbapi_con.cursor()
cursor.execute("SHOW VARIABLES LIKE 'sql_mode'")
realmode = cursor.fetchone()
if realmode is None:
LOG.warning(_LW('Unable to detect effective SQL mode'))
else:
realmode = realmode[1]
LOG.debug('MySQL server mode set to %s', realmode)
if 'TRADITIONAL' not in realmode.upper() and \
'STRICT_ALL_TABLES' not in realmode.upper():
LOG.warning(
_LW(
"MySQL SQL mode is '%s', "
"consider enabling TRADITIONAL or STRICT_ALL_TABLES"),
realmode)
@_init_events.dispatch_for("sqlite")

33
tests/sqlalchemy/test_sqlalchemy.py
View File

@ -453,19 +453,36 @@ class MysqlConnectTest(test_base.MySQLOpportunisticTestCase):
log = self.useFixture(fixtures.FakeLogger(level=logging.WARN))
engine = self._fixture(sql_mode=None)
mysql_conn = self.engine.raw_connection()
self.addCleanup(mysql_conn.close)
mysql_conn.detach()
mysql_cursor = mysql_conn.cursor()
@sqlalchemy.event.listens_for(
engine, "before_cursor_execute", retval=True)
def replace_stmt(
conn, cursor, statement, parameters,
context, executemany):
def execute(statement, parameters=()):
if "SHOW VARIABLES LIKE 'sql_mode'" in statement:
statement = "SHOW VARIABLES LIKE 'i_dont_exist'"
return statement, parameters
return mysql_cursor.execute(statement, parameters)
session._init_events.dispatch_on_drivername("mysql")(engine)
test_engine = sqlalchemy.create_engine(self.engine.url,
_initialize=False)
with mock.patch.object(
test_engine.pool, '_creator',
mock.Mock(
return_value=mock.Mock(
cursor=mock.Mock(
return_value=mock.Mock(
execute=execute,
fetchone=mysql_cursor.fetchone,
fetchall=mysql_cursor.fetchall
)
)
)
)
):
session._init_events.dispatch_on_drivername("mysql")(test_engine)
test_engine.raw_connection()
self.assertIn('Unable to detect effective SQL mode',
log.output)