From 8e1c6666238fd562d8ae203b83c01f91233ca9bf Mon Sep 17 00:00:00 2001
From: Roman Podoliaka <rpodolyaka@mirantis.com>
Date: Wed, 1 Oct 2014 16:10:20 +0300
Subject: [PATCH] Ensure create_engine() retries the initial connection test
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
(cherry picked from commit 01a54cc5cc43c8b497007dbb07c78dacd03c1ed2)
---
oslo/db/sqlalchemy/session.py | 34 +++++++++++++++++++++-------------
tests/sqlalchemy/test_sqlalchemy.py | 35 ++++++++++++++++++++++++++---------
2 files changed, 47 insertions(+), 22 deletions(-)
diff --git a/oslo/db/sqlalchemy/session.py b/oslo/db/sqlalchemy/session.py
index 882a9ea..57b5fb8 100644
--- a/oslo/db/sqlalchemy/session.py
+++ b/oslo/db/sqlalchemy/session.py
@@ -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")
diff --git a/tests/sqlalchemy/test_sqlalchemy.py b/tests/sqlalchemy/test_sqlalchemy.py
index 5ba3207..0aeeb05 100644
--- a/tests/sqlalchemy/test_sqlalchemy.py
+++ b/tests/sqlalchemy/test_sqlalchemy.py
@@ -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
-
- session._init_events.dispatch_on_drivername("mysql")(engine)
+ return mysql_cursor.execute(statement, parameters)
+
+ 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)