Thread: Wierd error message
I'm working with mod_python and pygresql (although I get virtualy the same error with psycopg too) Anyone know what the following error actualy means: Exception pg.InternalError: 'Connection already closed' in > ignored Does it mean the obvious: Some code tries to access a connection object that was already closed? but why the "in > ignored" then? Thanks, Alex Turner netEconomist
I have situation where I have one box with linux native 64 bit distribution (Gentoo on AMD) running pg 8.x and other box running a 32 bit distro running version of pg 8.x Is it posssible to take a "filesystem level backup" (copyiing all in $PGDATA directory) from 64 bit system and use it as $PGDATA in the native 32 bit system with the same version of postgresql ? Ie to have one big 64 bit server and eventually a small but cheap 32 bit box as an emergency backup ?
On Tue, Mar 15, 2005 at 02:29:51PM +0100, NTPT wrote: > I have situation where I have one box with linux native 64 bit > distribution (Gentoo on AMD) running pg 8.x and other box running a 32 bit > distro running version of pg 8.x > > Is it posssible to take a "filesystem level backup" (copyiing all in > $PGDATA directory) from 64 bit system and use it as $PGDATA in the native > 32 bit system with the same version of postgresql ? Doubt it, it's not explicitly supported. It might work, but padding changes, certain width changes, may screw you up. > Ie to have one big 64 bit server and eventually a small but cheap 32 bit > box as an emergency backup ? Use something like Slony, it's specifically supports this kind of usage... Have a nice day, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a > tool for doing 5% of the work and then sitting around waiting for someone > else to do the other 95% so you can sue them.
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Martijn van Oosterhout <kleptog@svana.org> writes:
> On Tue, Mar 15, 2005 at 02:29:51PM +0100, NTPT wrote:
>> Is it posssible to take a "filesystem level backup" (copyiing all in=20
>> $PGDATA directory) from 64 bit system and use it as $PGDATA in the native=
>> 32 bit system with the same version of postgresql ?
> Doubt it, it's not explicitly supported. It might work, but padding
> changes, certain width changes, may screw you up.
It might work if the main server were compiled as a 32-bit application
... but AFAIK the Intel-ish 64bit architectures mostly suck in 32-bit
emulation mode, so you'd not want to do that. It will almost certainly
*not* work to just cram 64-bit files onto a 32-bit machine, because the
file layout is dependent on MAXALIGN which will likely be different.
> Use something like Slony, it's specifically supports this kind of
> usage...
Agreed.
regards, tom lane
On Tue, 2005-03-15 at 07:29, NTPT wrote: > I have situation where I have one box with linux native 64 bit distribution > (Gentoo on AMD) running pg 8.x and other box running a 32 bit distro > running version of pg 8.x > > Is it posssible to take a "filesystem level backup" (copyiing all in > $PGDATA directory) from 64 bit system and use it as $PGDATA in the native 32 > bit system with the same version of postgresql ? > > > Ie to have one big 64 bit server and eventually a small but cheap 32 bit box > as an emergency backup ? Following up on what Tom wrote, I'd suggest using Slony-I to keep the two machines in sync.
On Tue, Mar 15, 2005 at 07:32:43AM -0500, Alex Turner wrote: > I'm working with mod_python and pygresql (although I get virtualy the > same error with psycopg too) What's the exact error you get with psycopg? > Anyone know what the following error actualy means: > > Exception pg.InternalError: 'Connection already closed' in > ignored > > Does it mean the obvious: Some code tries to access a connection > object that was already closed? That would be my guess. What are you doing that results in the error? Is it easily repeatable? Does anything else show up in the web server or database logs? > but why the "in > ignored" then? Can you tell us more about the setup? What are all the pieces involved and their versions? -- Michael Fuhr http://www.fuhr.org/~mfuhr/
I'm running apache 2.0.52 on pentium III 866 using RedHat EL3 - kernel 2.4.21-27.0.2.EL I'm using mod_python 3.1.3 and the postgresql-python-8.0.1-1PGDG RPM. Unfortunately the error is not readibly reproducable. Sometimes it happens, and sometimes it doesn't. Normaly if I reload the page it goes away. There are cron jobs that make HTTP calls to the system every 5 minutes also written in python. When httpd is isdle "lsof | grep httpd | grep 5432" shows nothing. We have only been experiencing this error recently. It may just be conincidence, but it has been noticed since upgrading to 8.0. much to my amazement, error_log contains: [Wed Mar 16 00:38:41 2005] [error] [client 66.216.147.134] PythonHandler ContentGenerator: STDERR Contained data: Exception pg.InternalError: 'Connection already closed' in <bound method PostgresqlDBConnection.__del__ of <PGDBC.PostgresqlDBConnection instance at 0x8b3428c>> ignored\n, referer: http://www.totalleads.com/client_administration/display_employee_postal_code_list.nece?eid=13071§ion=users The STDERR part I can explain: my web page evals and calls some python code. I think I know the problem. The current release is printing an error to stderr if a database connection that is aready closed is tried to be closed again. I am catching anything on stderr and raising it as an exception. So I think the problem is solved. Alex Turner netEconomist On Tue, 15 Mar 2005 11:13:56 -0700, Michael Fuhr <mike@fuhr.org> wrote: > On Tue, Mar 15, 2005 at 07:32:43AM -0500, Alex Turner wrote: > > > I'm working with mod_python and pygresql (although I get virtualy the > > same error with psycopg too) > > What's the exact error you get with psycopg? > > > Anyone know what the following error actualy means: > > > > Exception pg.InternalError: 'Connection already closed' in > ignored > > > > Does it mean the obvious: Some code tries to access a connection > > object that was already closed? > > That would be my guess. What are you doing that results in the > error? Is it easily repeatable? Does anything else show up in the > web server or database logs? > > > but why the "in > ignored" then? > > Can you tell us more about the setup? What are all the pieces > involved and their versions? > > -- > Michael Fuhr > http://www.fuhr.org/~mfuhr/ >