Re: [SQLObject] MySQL: Commands out of sync; you can't run this command now

[Maciej (M. B. <ma...@op...>]

2013/4/16 Oleg Broytman <ph...@ph...>
>
> On Tue, Apr 16, 2013 at 10:52:29AM +0100, "Maciej (Matchek) Blizi??ski" <ma...@op...> wrote:
> >   File "/opt/csw/lib/python/site-packages/sqlobject/mysql/mysqlconnection.py",
> > line 71, in makeConnection
> >     conn.ping(True) # Attempt to reconnect. This setting is persistent.
> > ProgrammingError: (2014, "Commands out of sync; you can't run this command now")
>
>    conn.ping() is intended to reopen the connection after a timeout;
> AFAIR the default timeout is 3600 seconds, not a few minutes. There
> shouldn't be any problem with ping after a minute or two.
>
>    "Commands out of sync"means the application calls functions in the
> wrong order:
> https://dev.mysql.com/doc/refman/5.1/en/commands-out-of-sync.html
>    Is the app multithreaded? Could it be the app tries to reuse the same
> transaction in different threads?

That was my suspicion too, but it's an wsgi application which doesn't
use threads. I experimented by reducing the number of wsgi application
copies / threads in Apache config to 1. It didn't help, so it's
probably not that.

I've got an update: I noticed that MySQLdb[1] has a new version (1.2.4)
so I upgraded it and the problem seems to have gone away. Maybe it was
some interplay between SqlObject and the MySQL driver for Python, or
just simply the db driver had a problem.

Maciej

[1] https://pypi.python.org/pypi/MySQL-python