Here is a the problem. If you put queries in try... except you must
follow this pattern:
try:
... any db io ...
except:
db.rollback()
If you do not rollback any subsequent attempt to commit or access the
db again results in an error.
On Nov 10, 2:07 pm, David Zejda <[email protected]> wrote:
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> This one is also quite common:
>
> Traceback (most recent call last):
> File "/opt/web2py/gluon/main.py", line 475, in wsgibase
> BaseAdapter.close_all_instances(BaseAdapter.rollback)
> File "/opt/web2py/gluon/sql.py", line 810, in close_all_instances
> action(instance)
> File "/opt/web2py/gluon/sql.py", line 1393, in rollback
> self._connection.rollback()
> ProgrammingError: (2014, "Commands out of sync; you can't run this
> command now")
>
> Yes, I have many queries also in try..except blocks. But it is really
> hard to find what exactly is the root of problem because I did not
> reveal any meaningful shape in the error occurencies. At least not yet. :(
>
> D.
>
>
>
> mdipierro wrote:
> > Has anybody else here had a similar problem?
>
> > massimo
>
> > On Nov 9, 11:29 am, David Zejda <[email protected]> wrote:
> > Hi :)
>
> > E.g. now the exception was raised by the web2py internal db
> > initialization routine:
>
> > 28: db = SQLDB('mysql://myus:myp...@localhost:330h6/mydb', pool_size=10)
>
> > Traceback (most recent call last):
> > File "/opt/web2py/gluon/restricted.py", line 188, in restricted
> > exec ccode in environment
> > File "/opt/web2py/applications/myapp/compiled/models_db.py", line 28,
> > in <module>
> > File "/opt/web2py/gluon/sql.py", line 978, in __init__
> > self._execute('SET FOREIGN_KEY_CHECKS=1;')
> > File "/opt/web2py/gluon/sql.py", line 977, in <lambda>
> > self._execute = lambda *a, **b: self._cursor.execute(*a, **b)
> > File "/var/lib/python-support/python2.5/MySQLdb/cursors.py", line 166,
> > in execute
> > self.errorhandler(self, exc, value)
> > File "/var/lib/python-support/python2.5/MySQLdb/connections.py", line
> > 35, in defaulterrorhandler
> > raise errorclass, errorvalue
> > ProgrammingError: (2014, "Commands out of sync; you can't run this
> > command now")
>
> > I'm thinking about possibility to raise the size of my poll. But in the
> > past with higher poll I think I was receiving more OperationalError:
> > (2006, 'MySQL server has gone away'). Because I am referring to a live
> > server, I would prefer to avoid experiments which could make frequency
> > of db errors even worse :)
>
> > thanks & wishing you a nice day..
> > David
>
> > mdipierro wrote:
> >>>> I cannot say without looking at the code. MySQL has lots of
> >>>> undocumented quirks about what you can do and what you cannot do
> >>>> within one transaction.
> >>>> Try add a db.commit() after each insert/unpdate/form.accepts/
> >>>> crud.update/crud.select IF you do a select after that.
> >>>> Do you have any try:...except in your controllers and db queries
> >>>> inside?
> >>>> On Nov 8, 2:57 am, David Zejda <[email protected]> wrote:
> >>>> The MySQL error occurs quite often, several times every day. The app has
> >>>> about 20000 page views daily and heavily communicates with db (tens of
> >>>> queries per request, in db I have about 100 tables). Currently I have
> >>>> pool with size for 10 connections.
> >>>> Meaning of the error message is described here:
> >>>>http://dev.mysql.com/doc/refman/4.1/en/commands-out-of-sync.html
> >>>> It seems that with MySQL statements on the same db connection have to be
> >>>> exhausted one-by-one, never in parallel. Two statements returning data
> >>>> to the process must be using separate DBConnections (possibly to the
> >>>> same host/db). Multiple statements on the same connection are supported,
> >>>> but only 1 may be in a state to 'fetch' data.
> >>>> Traces for the errors look like this:
> >>>> File "/opt/web2py/gluon/sql.py", line 3378, in count
> >>>> return self.select('count(*)')[0]._extra['count(*)']
> >>>> File "/opt/web2py/gluon/sql.py", line 3237, in select
> >>>> rows = response(query)
> >>>> File "/opt/web2py/gluon/sql.py", line 3232, in response
> >>>> db._execute(query)
> >>>> File "/opt/web2py/gluon/sql.py", line 977, in <lambda>
> >>>> self._execute = lambda *a, **b: self._cursor.execute(*a, **b)
> >>>> File "/var/lib/python-support/python2.5/MySQLdb/cursors.py", line 166,
> >>>> in execute
> >>>> self.errorhandler(self, exc, value)
> >>>> File "/var/lib/python-support/python2.5/MySQLdb/connections.py", line
> >>>> 35, in defaulterrorhandler
> >>>> raise errorclass, errorvalue
> >>>> ProgrammingError: (2014, "Commands out of sync; you can't run this
> >>>> command now")
> >>>> Or e.g.:
> >>>> Traceback (most recent call last):
> >>>> File "/opt/web2py/gluon/main.py", line 475, in wsgibase
> >>>> BaseAdapter.close_all_instances(BaseAdapter.rollback)
> >>>> File "/opt/web2py/gluon/sql.py", line 810, in close_all_instances
> >>>> action(instance)
> >>>> File "/opt/web2py/gluon/sql.py", line 1393, in rollback
> >>>> self._connection.rollback()
> >>>> ProgrammingError: (2014, "Commands out of sync; you can't run this
> >>>> command now")
> >>>> Do you have any tips how to aviod these errors?
> >>>> Thanks!
>
> - --
> David Zejda, Open-IT cz
> web development & serviceshttp://www.o-it.info
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