Performance bug of server

[esikachev]

When server working on production lab we have the next error when you try to connect to host which exist in DB:
Traceback (most recent call last): File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/flask/app.py", line 1994, in __call__ return self.wsgi_app(environ, start_response) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/flask/app.py", line 1985, in wsgi_app response = self.handle_exception(e) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/flask/app.py", line 1540, in handle_exception reraise(exc_type, exc_value, tb) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/flask/app.py", line 1982, in wsgi_app response = self.full_dispatch_request() File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/flask/app.py", line 1614, in full_dispatch_request rv = self.handle_user_exception(e) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/flask/app.py", line 1517, in handle_user_exception reraise(exc_type, exc_value, tb) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/flask/app.py", line 1612, in full_dispatch_request rv = self.dispatch_request() File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/flask/app.py", line 1598, in dispatch_request return self.view_functions[rule.endpoint](**req.view_args) File "/home/ubuntu/my-dev-server/my_dev_server/server/main.py", line 72, in user_get models.User.username == id)).first() File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2659, in first ret = list(self[0:1]) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2457, in __getitem__ return list(res) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2761, in __iter__ return self._execute_and_instances(context) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2776, in _execute_and_instances result = conn.execute(querycontext.statement, self._params) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 914, in execute return meth(self, multiparams, params) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/sql/elements.py", line 323, in _execute_on_connection return connection._execute_clauseelement(self, multiparams, params) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1010, in _execute_clauseelement compiled_sql, distilled_params File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1078, in _execute_context None, None) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1341, in _handle_dbapi_exception exc_info File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/util/compat.py", line 203, in raise_from_cause reraise(type(exception), exception, tb=exc_tb, cause=cause) File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1071, in _execute_context conn = self._revalidate_connection() File "/home/ubuntu/my-dev-server/.tox/venv/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 391, in _revalidate_connection "Can't reconnect until invalid " StatementError: (sqlalchemy.exc.InvalidRequestError) Can't reconnect until invalid transaction is rolled back [SQL: u'SELECT users.id AS users_id, users.username AS users_username, users.email AS users_email, users.password AS users_password, users.registered_on AS users_ registered_on \nFROM users \nWHERE users.id = %(id_1)s OR users.username = %(username_1)s \n LIMIT %(param_1)s'] [parameters: [immutabledict({})]]

WORKAROUND: Restart the server

[IlyaMenkov]

I dont understand how to reproduce this bug. (!?!?!)

[esikachev]

This bug was found on pre-production server. We need several days for it