Re: [sqlalchemy] Sudden Connection issues
Hi All
Just to put closure on this issue, I finally sorted it out as a bug in the
connector. This has now been resolved and the latest build has the correction.
:-) As a matter of interest, the line db.conn.protocol should have been
db.protocol.. Anyway - all's well that ends well.. :-)
Cheers
Warwick
On Aug 27, 2010, at 4:39 AM, Warwick Prince wrote:
Hi Michael
OK, I've invested (wasted?) my entire day on this connection issue and have
the following to report. Hopefully, the hints I've managed to find may
trigger something with you that will point me in the right direction.
In recap; the issue was I could not get a simple engine to connect to the
MySQL database. This used to work on this server with the current
configuration and simply seemed to stop working.
e = create_engine('mysql+mysqlconnector://user:passw...@127.0.0.1/testdb',
encoding='utf8', echo=False)
e.connect()
(Traceback below from previous messages)
So, I followed all the code through and found that it actually failing at
the point where in cursor.py it's attempting to create a new cursor.
def set_connection(self, db):
try:
if isinstance(db.conn.protocol,protocol.MySQLProtocol):
self.db = weakref.ref(db)
if self not in self.db().cursors:
self.db().cursors.append(self)
except Exception as message:
raise errors.InterfaceError(errno=2048)
The db appears to be correct (I looked), protocol.MySQLProtocol appears to
be correct BUT db.conn = None ! Therefore it raises 2048
So, after many hours I can not find where db.conn is set or what it is
supposed to be in the first place!Note: I have a virtually identical
setup on my XP VM, and the same example of engine.connect() works fine.
What I'm looking for is a little info on what db.conn should be, where is it
set, how can it be NOT set etc.Your help would be most appreciated.
Incidentally, all was not a waste of time as I traversed nearly ALL of the
SA code today and picked up a few nice tips.. Thanks! :-)
Well, that above is not part of SQLAlchemy. I would assume, since its
called cursor.py and is dealing with MySQL internals, that its part of MySQL
connector, so you should email on their list (and also you can test things
without SQLAlchemy at all, just use a script with MySQL connector directly).
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Re: [sqlalchemy] Sudden Connection issues
Hi Michael
OK, I've invested (wasted?) my entire day on this connection issue and have the
following to report. Hopefully, the hints I've managed to find may trigger
something with you that will point me in the right direction.
In recap; the issue was I could not get a simple engine to connect to the MySQL
database. This used to work on this server with the current configuration and
simply seemed to stop working.
e = create_engine('mysql+mysqlconnector://user:passw...@127.0.0.1/testdb',
encoding='utf8', echo=False)
e.connect()
(Traceback below from previous messages)
So, I followed all the code through and found that it actually failing at the
point where in cursor.py it's attempting to create a new cursor.
def set_connection(self, db):
try:
if isinstance(db.conn.protocol,protocol.MySQLProtocol):
self.db = weakref.ref(db)
if self not in self.db().cursors:
self.db().cursors.append(self)
except Exception as message:
raise errors.InterfaceError(errno=2048)
The db appears to be correct (I looked), protocol.MySQLProtocol appears to be
correct BUT db.conn = None ! Therefore it raises 2048
So, after many hours I can not find where db.conn is set or what it is supposed
to be in the first place!Note: I have a virtually identical setup on my XP
VM, and the same example of engine.connect() works fine.
What I'm looking for is a little info on what db.conn should be, where is it
set, how can it be NOT set etc.Your help would be most appreciated.
Incidentally, all was not a waste of time as I traversed nearly ALL of the SA
code today and picked up a few nice tips.. Thanks! :-)
Cheers
Warwick
Warwick Prince
Managing Director
mobile: +61 411 026 992
skype: warwickprince
phone: +61 7 3102 3730
fax: +61 7 3319 6734
web: www.mushroomsys.com
On 26/08/2010, at 3:37 PM, Michael Bayer wrote:
On Aug 25, 2010, at 11:09 PM, Warwick Prince wrote:
HI Michael
Excellent. Thanks for the pointers - I'll investigate further and get back
to you. This is really strange as I do not believe that I changed anything
from the point it all worked, to the point at which it didn't! (I'm sure
there will be something however - there always is..). :-) I'll let you
know how I go. When I get it going again, I'll hit you with the REAL
questions I have..
those connection issues are fixed in tip (not your MySQL problem, though).
Cheers
Warwick
On 26/08/2010, at 12:43 PM, Michael Bayer wrote:
On Aug 25, 2010, at 10:11 PM, Warwick Prince wrote:
Hi All
This is my first post here, so I wish it were a little more spectacular..
:-)
I have been working happily with SA 0.6.x on Windows 2003 server with
MySQL and the Sun Python Connector. I have an identical config running
(and working) on XP.
I was testing my code which had been working perfectly, and suddenly
started getting this message which I had never seen before;
Traceback (most recent call last):
File pyshell#3, line 1, in module
e.connect()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1731,
in connect
return self.Connection(self, **kwargs)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 821,
in __init__
self.__connection = connection or engine.raw_connection()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1787,
in raw_connection
return self.pool.unique_connection()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 135, in
unique_connection
return _ConnectionFairy(self).checkout()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 329, in
__init__
rec = self._connection_record = pool.get()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 177, in get
return self.do_get()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 692, in
do_get
con = self.create_connection()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 138, in
create_connection
return _ConnectionRecord(self)
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 218, in
__init__
l.first_connect(self.connection, self)
File C:\Python26\lib\site-packages\sqlalchemy\engine\strategies.py, line
145, in first_connect
dialect.initialize(c)
File C:\Python26\lib\site-packages\sqlalchemy\dialects\mysql\base.py,
line 1774, in initialize
default.DefaultDialect.initialize(self, connection)
File C:\Python26\lib\site-packages\sqlalchemy\engine\default.py, line
144, in initialize
self._get_default_schema_name(connection)
File C:\Python26\lib\site-packages\sqlalchemy\dialects\mysql\base.py,
line 1739, in _get_default_schema_name
return connection.execute('SELECT DATABASE()').scalar()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1157,
in execute
params)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1252,
in _execute_text
Re: [sqlalchemy] Sudden Connection issues
On Aug 27, 2010, at 4:39 AM, Warwick Prince wrote:
Hi Michael
OK, I've invested (wasted?) my entire day on this connection issue and have
the following to report. Hopefully, the hints I've managed to find may
trigger something with you that will point me in the right direction.
In recap; the issue was I could not get a simple engine to connect to the
MySQL database. This used to work on this server with the current
configuration and simply seemed to stop working.
e = create_engine('mysql+mysqlconnector://user:passw...@127.0.0.1/testdb',
encoding='utf8', echo=False)
e.connect()
(Traceback below from previous messages)
So, I followed all the code through and found that it actually failing at the
point where in cursor.py it's attempting to create a new cursor.
def set_connection(self, db):
try:
if isinstance(db.conn.protocol,protocol.MySQLProtocol):
self.db = weakref.ref(db)
if self not in self.db().cursors:
self.db().cursors.append(self)
except Exception as message:
raise errors.InterfaceError(errno=2048)
The db appears to be correct (I looked), protocol.MySQLProtocol appears to be
correct BUT db.conn = None ! Therefore it raises 2048
So, after many hours I can not find where db.conn is set or what it is
supposed to be in the first place!Note: I have a virtually identical
setup on my XP VM, and the same example of engine.connect() works fine.
What I'm looking for is a little info on what db.conn should be, where is it
set, how can it be NOT set etc.Your help would be most appreciated.
Incidentally, all was not a waste of time as I traversed nearly ALL of the SA
code today and picked up a few nice tips.. Thanks! :-)
Well, that above is not part of SQLAlchemy. I would assume, since its called
cursor.py and is dealing with MySQL internals, that its part of MySQL
connector, so you should email on their list (and also you can test things
without SQLAlchemy at all, just use a script with MySQL connector directly).
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Re: [sqlalchemy] Sudden Connection issues
Hi Michael
Sorry about that - it had been a long day and I didn't realise I was quoting
code from the connector! I'll get onto them and see if they can help.
Cheers
Warwick
Warwick Prince
Managing Director
mobile: +61 411 026 992
skype: warwickprince
phone: +61 7 3102 3730
fax: +61 7 3319 6734
web: www.mushroomsys.com
On 27/08/2010, at 11:40 PM, Michael Bayer wrote:
On Aug 27, 2010, at 4:39 AM, Warwick Prince wrote:
Hi Michael
OK, I've invested (wasted?) my entire day on this connection issue and have
the following to report. Hopefully, the hints I've managed to find may
trigger something with you that will point me in the right direction.
In recap; the issue was I could not get a simple engine to connect to the
MySQL database. This used to work on this server with the current
configuration and simply seemed to stop working.
e = create_engine('mysql+mysqlconnector://user:passw...@127.0.0.1/testdb',
encoding='utf8', echo=False)
e.connect()
(Traceback below from previous messages)
So, I followed all the code through and found that it actually failing at
the point where in cursor.py it's attempting to create a new cursor.
def set_connection(self, db):
try:
if isinstance(db.conn.protocol,protocol.MySQLProtocol):
self.db = weakref.ref(db)
if self not in self.db().cursors:
self.db().cursors.append(self)
except Exception as message:
raise errors.InterfaceError(errno=2048)
The db appears to be correct (I looked), protocol.MySQLProtocol appears to
be correct BUT db.conn = None ! Therefore it raises 2048
So, after many hours I can not find where db.conn is set or what it is
supposed to be in the first place!Note: I have a virtually identical
setup on my XP VM, and the same example of engine.connect() works fine.
What I'm looking for is a little info on what db.conn should be, where is it
set, how can it be NOT set etc.Your help would be most appreciated.
Incidentally, all was not a waste of time as I traversed nearly ALL of the
SA code today and picked up a few nice tips.. Thanks! :-)
Well, that above is not part of SQLAlchemy. I would assume, since its
called cursor.py and is dealing with MySQL internals, that its part of MySQL
connector, so you should email on their list (and also you can test things
without SQLAlchemy at all, just use a script with MySQL connector directly).
--
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[sqlalchemy] Sudden Connection issues
Hi All
This is my first post here, so I wish it were a little more spectacular.. :-)
I have been working happily with SA 0.6.x on Windows 2003 server with MySQL and
the Sun Python Connector. I have an identical config running (and working) on
XP.
I was testing my code which had been working perfectly, and suddenly started
getting this message which I had never seen before;
Traceback (most recent call last):
File pyshell#3, line 1, in module
e.connect()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1731, in
connect
return self.Connection(self, **kwargs)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 821, in
__init__
self.__connection = connection or engine.raw_connection()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1787, in
raw_connection
return self.pool.unique_connection()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 135, in
unique_connection
return _ConnectionFairy(self).checkout()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 329, in __init__
rec = self._connection_record = pool.get()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 177, in get
return self.do_get()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 692, in do_get
con = self.create_connection()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 138, in
create_connection
return _ConnectionRecord(self)
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 218, in __init__
l.first_connect(self.connection, self)
File C:\Python26\lib\site-packages\sqlalchemy\engine\strategies.py, line
145, in first_connect
dialect.initialize(c)
File C:\Python26\lib\site-packages\sqlalchemy\dialects\mysql\base.py, line
1774, in initialize
default.DefaultDialect.initialize(self, connection)
File C:\Python26\lib\site-packages\sqlalchemy\engine\default.py, line 144,
in initialize
self._get_default_schema_name(connection)
File C:\Python26\lib\site-packages\sqlalchemy\dialects\mysql\base.py, line
1739, in _get_default_schema_name
return connection.execute('SELECT DATABASE()').scalar()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1157, in
execute
params)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1252, in
_execute_text
parameters=parameters)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1348, in
__create_execution_context
None, None)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1311, in
_handle_dbapi_exception
self.invalidate(e)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 961, in
invalidate
if self.__connection.is_valid:
AttributeError: 'MySQL' object has no attribute 'is_valid'
I have spent a significant amount of time on this, and nothing makes sense.
I've run the unittest.py code that comes with the connector, and (connecting to
the same DB) ran the tests with success. Firstly, it would appear that there
is a possible bug in base.py at line 962 where it asks if
self.__connection.is_valid: as this attribute has not been created yet, and is
conditionally created. However, this is not the root of the issue, merely a
distraction. (I forced this to exist and have a value, but the problem just
fell through to further down the code)
I can get this error by simply doing this (now) when this all has worked for
days.
e = create_engine('mysql+mysqlconnector://user:passw...@127.0.0.1/testdb',
encoding='utf8', echo=False)
e.connect()
Any clues - as this is driving me nuts! Can't do ANYTHING now because I an no
longer connect to the DB. DB manager and other tools all show MySQL happily
ticking along. I have rebooted the server.
As a possible solution, are there any other stable MySQL connectors out there
that are easy to install on a Windows platform? The Python Connector one
chosen has been good so far, but if that turns out to be the issue - it's gone!
Cheers
Warwick
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Re: [sqlalchemy] Sudden Connection issues
On Aug 25, 2010, at 10:11 PM, Warwick Prince wrote:
Hi All
This is my first post here, so I wish it were a little more spectacular.. :-)
I have been working happily with SA 0.6.x on Windows 2003 server with MySQL
and the Sun Python Connector. I have an identical config running (and
working) on XP.
I was testing my code which had been working perfectly, and suddenly started
getting this message which I had never seen before;
Traceback (most recent call last):
File pyshell#3, line 1, in module
e.connect()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1731,
in connect
return self.Connection(self, **kwargs)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 821, in
__init__
self.__connection = connection or engine.raw_connection()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1787,
in raw_connection
return self.pool.unique_connection()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 135, in
unique_connection
return _ConnectionFairy(self).checkout()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 329, in
__init__
rec = self._connection_record = pool.get()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 177, in get
return self.do_get()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 692, in do_get
con = self.create_connection()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 138, in
create_connection
return _ConnectionRecord(self)
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 218, in
__init__
l.first_connect(self.connection, self)
File C:\Python26\lib\site-packages\sqlalchemy\engine\strategies.py, line
145, in first_connect
dialect.initialize(c)
File C:\Python26\lib\site-packages\sqlalchemy\dialects\mysql\base.py, line
1774, in initialize
default.DefaultDialect.initialize(self, connection)
File C:\Python26\lib\site-packages\sqlalchemy\engine\default.py, line 144,
in initialize
self._get_default_schema_name(connection)
File C:\Python26\lib\site-packages\sqlalchemy\dialects\mysql\base.py, line
1739, in _get_default_schema_name
return connection.execute('SELECT DATABASE()').scalar()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1157,
in execute
params)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1252,
in _execute_text
parameters=parameters)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1348,
in __create_execution_context
None, None)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1311,
in _handle_dbapi_exception
self.invalidate(e)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 961, in
invalidate
if self.__connection.is_valid:
AttributeError: 'MySQL' object has no attribute 'is_valid'
I have spent a significant amount of time on this, and nothing makes sense.
I've run the unittest.py code that comes with the connector, and (connecting
to the same DB) ran the tests with success. Firstly, it would appear that
there is a possible bug in base.py at line 962 where it asks if
self.__connection.is_valid: as this attribute has not been created yet, and
is conditionally created.
__connection is created in the constructor, and it may get del'ed by close or
invalidate. There's a check for closed right there, so its only if
invalidate() is called twice that there'd be an issue. But that's not what's
happening here, since __connection is present.
Its still a bug on our part though, partially, there's an edge case where the
__connection member is not the usual ConnectionFairy wrapper we use, and is the
raw DBAPI connection, and that is during the initilization phase of a new
connection. In your stack trace, a new connection is acquired from the DBAPI,
and we're calling SELECT DATABASE() on it. That is failing. Very
unusually, it is failing with an exception that passes the is_disconnect
test, which means the errno is in (2006, 2013, 2014, 2045, 2055, 2048)
according to the mysqlconnector dialect, and means the connection has been
lost. Interestingly, that is one more code than we have in base.py. So that
list of codes is suspect (the myconnpy guys provided some of this code) - the
base list used by the other MySQL dialects is (2006, 2013, 2014, 2045, 2055).
The exception then passes off to invalidate() which wasn't expecting a raw
DBAPI connection and it breaks. Ticket #1894 is added.
For the immediate issue you'd need to figure out what error SELECT DATABASE()
is returning.
However, this is not the root of the issue, merely a distraction. (I forced
this to exist and have a value, but the problem just fell through to further
down the code)
I can get this error by simply doing this (now) when this all has worked for
days.
e =
Re: [sqlalchemy] Sudden Connection issues
HI Michael
Excellent. Thanks for the pointers - I'll investigate further and get back to
you. This is really strange as I do not believe that I changed anything from
the point it all worked, to the point at which it didn't! (I'm sure there
will be something however - there always is..). :-) I'll let you know how I
go. When I get it going again, I'll hit you with the REAL questions I have..
Cheers
Warwick
On 26/08/2010, at 12:43 PM, Michael Bayer wrote:
On Aug 25, 2010, at 10:11 PM, Warwick Prince wrote:
Hi All
This is my first post here, so I wish it were a little more spectacular..
:-)
I have been working happily with SA 0.6.x on Windows 2003 server with MySQL
and the Sun Python Connector. I have an identical config running (and
working) on XP.
I was testing my code which had been working perfectly, and suddenly started
getting this message which I had never seen before;
Traceback (most recent call last):
File pyshell#3, line 1, in module
e.connect()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1731,
in connect
return self.Connection(self, **kwargs)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 821, in
__init__
self.__connection = connection or engine.raw_connection()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1787,
in raw_connection
return self.pool.unique_connection()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 135, in
unique_connection
return _ConnectionFairy(self).checkout()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 329, in
__init__
rec = self._connection_record = pool.get()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 177, in get
return self.do_get()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 692, in do_get
con = self.create_connection()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 138, in
create_connection
return _ConnectionRecord(self)
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 218, in
__init__
l.first_connect(self.connection, self)
File C:\Python26\lib\site-packages\sqlalchemy\engine\strategies.py, line
145, in first_connect
dialect.initialize(c)
File C:\Python26\lib\site-packages\sqlalchemy\dialects\mysql\base.py, line
1774, in initialize
default.DefaultDialect.initialize(self, connection)
File C:\Python26\lib\site-packages\sqlalchemy\engine\default.py, line 144,
in initialize
self._get_default_schema_name(connection)
File C:\Python26\lib\site-packages\sqlalchemy\dialects\mysql\base.py, line
1739, in _get_default_schema_name
return connection.execute('SELECT DATABASE()').scalar()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1157,
in execute
params)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1252,
in _execute_text
parameters=parameters)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1348,
in __create_execution_context
None, None)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1311,
in _handle_dbapi_exception
self.invalidate(e)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 961, in
invalidate
if self.__connection.is_valid:
AttributeError: 'MySQL' object has no attribute 'is_valid'
I have spent a significant amount of time on this, and nothing makes sense.
I've run the unittest.py code that comes with the connector, and (connecting
to the same DB) ran the tests with success. Firstly, it would appear that
there is a possible bug in base.py at line 962 where it asks if
self.__connection.is_valid: as this attribute has not been created yet, and
is conditionally created.
__connection is created in the constructor, and it may get del'ed by close or
invalidate. There's a check for closed right there, so its only if
invalidate() is called twice that there'd be an issue. But that's not what's
happening here, since __connection is present.
Its still a bug on our part though, partially, there's an edge case where the
__connection member is not the usual ConnectionFairy wrapper we use, and is
the raw DBAPI connection, and that is during the initilization phase of a new
connection. In your stack trace, a new connection is acquired from the
DBAPI, and we're calling SELECT DATABASE() on it. That is failing. Very
unusually, it is failing with an exception that passes the is_disconnect
test, which means the errno is in (2006, 2013, 2014, 2045, 2055, 2048)
according to the mysqlconnector dialect, and means the connection has been
lost. Interestingly, that is one more code than we have in base.py. So that
list of codes is suspect (the myconnpy guys provided some of this code) - the
base list used by the other MySQL dialects is (2006, 2013, 2014, 2045, 2055).
The exception then passes off to invalidate() which wasn't expecting a raw
Re: [sqlalchemy] Sudden Connection issues
On Aug 25, 2010, at 11:09 PM, Warwick Prince wrote:
HI Michael
Excellent. Thanks for the pointers - I'll investigate further and get back
to you. This is really strange as I do not believe that I changed anything
from the point it all worked, to the point at which it didn't! (I'm sure
there will be something however - there always is..). :-) I'll let you
know how I go. When I get it going again, I'll hit you with the REAL
questions I have..
those connection issues are fixed in tip (not your MySQL problem, though).
Cheers
Warwick
On 26/08/2010, at 12:43 PM, Michael Bayer wrote:
On Aug 25, 2010, at 10:11 PM, Warwick Prince wrote:
Hi All
This is my first post here, so I wish it were a little more spectacular..
:-)
I have been working happily with SA 0.6.x on Windows 2003 server with MySQL
and the Sun Python Connector. I have an identical config running (and
working) on XP.
I was testing my code which had been working perfectly, and suddenly
started getting this message which I had never seen before;
Traceback (most recent call last):
File pyshell#3, line 1, in module
e.connect()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1731,
in connect
return self.Connection(self, **kwargs)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 821,
in __init__
self.__connection = connection or engine.raw_connection()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1787,
in raw_connection
return self.pool.unique_connection()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 135, in
unique_connection
return _ConnectionFairy(self).checkout()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 329, in
__init__
rec = self._connection_record = pool.get()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 177, in get
return self.do_get()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 692, in do_get
con = self.create_connection()
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 138, in
create_connection
return _ConnectionRecord(self)
File C:\Python26\lib\site-packages\sqlalchemy\pool.py, line 218, in
__init__
l.first_connect(self.connection, self)
File C:\Python26\lib\site-packages\sqlalchemy\engine\strategies.py, line
145, in first_connect
dialect.initialize(c)
File C:\Python26\lib\site-packages\sqlalchemy\dialects\mysql\base.py,
line 1774, in initialize
default.DefaultDialect.initialize(self, connection)
File C:\Python26\lib\site-packages\sqlalchemy\engine\default.py, line
144, in initialize
self._get_default_schema_name(connection)
File C:\Python26\lib\site-packages\sqlalchemy\dialects\mysql\base.py,
line 1739, in _get_default_schema_name
return connection.execute('SELECT DATABASE()').scalar()
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1157,
in execute
params)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1252,
in _execute_text
parameters=parameters)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1348,
in __create_execution_context
None, None)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 1311,
in _handle_dbapi_exception
self.invalidate(e)
File C:\Python26\lib\site-packages\sqlalchemy\engine\base.py, line 961,
in invalidate
if self.__connection.is_valid:
AttributeError: 'MySQL' object has no attribute 'is_valid'
I have spent a significant amount of time on this, and nothing makes sense.
I've run the unittest.py code that comes with the connector, and
(connecting to the same DB) ran the tests with success. Firstly, it would
appear that there is a possible bug in base.py at line 962 where it asks
if self.__connection.is_valid: as this attribute has not been created yet,
and is conditionally created.
__connection is created in the constructor, and it may get del'ed by close
or invalidate. There's a check for closed right there, so its only if
invalidate() is called twice that there'd be an issue. But that's not
what's happening here, since __connection is present.
Its still a bug on our part though, partially, there's an edge case where
the __connection member is not the usual ConnectionFairy wrapper we use, and
is the raw DBAPI connection, and that is during the initilization phase of a
new connection. In your stack trace, a new connection is acquired from the
DBAPI, and we're calling SELECT DATABASE() on it. That is failing. Very
unusually, it is failing with an exception that passes the is_disconnect
test, which means the errno is in (2006, 2013, 2014, 2045, 2055, 2048)
according to the mysqlconnector dialect, and means the connection has been
lost. Interestingly, that is one more code than we have in base.py. So
that list of codes is suspect (the myconnpy guys provided some of this code)
- the base list used by the other
