Thread: pgsql server reset the connection immediately after connected

This probably means the server terminated abnormally before or while processing the request.

On 11/01/2012 07:24 PM, Dongkuo Ma wrote:
> Hi
> Sorry for my English.
> I'm running pgsql8.4 server on debian,the client is the python
> library(psycopg2) on the same mechine.
> The client connect server via 127.0.0.1:5432 <http://127.0.0.1:5432>.
>
> The psycopg2 connect function /succesed,but throw a exception /
>
> server closed the connection unexpectedly
>
> This probably means the server terminated abnormally before or while
> processing the request.

Not sure how the connect function could succeed and throw an exception
at the same time?
    Some more explanation may be needed.


What does the Postgres log show?


>
> /
> /
>
>


--
Adrian Klaver
adrian.klaver@gmail.com

On 11/01/2012 07:32 PM, Dongkuo Ma wrote:
> Sorry!
> I typed the enter key and sent the uncomplete message.
>
>
> The psycopg2 connect function succesed,but throw a exception
>
> server closed the connection unexpectedly
> This probably means the server terminated abnormally before or while
> processing the request.
>
> when executing any sql statement.

What is the Python code being used?

>
> Using tcpdump, I found the server reset the connection  immediately
> after connected, and i cann't find any log about this.

Should be in /var/log/postgresql

> This is the tcpdump log http://pastebin.com/uW0at4Zd




--
Adrian Klaver
adrian.klaver@gmail.com

On 11/01/2012 07:57 PM, Dongkuo Ma wrote:
> Hi
> the python code is
>
> logging.info <http://logging.info>("database connecting...")
> conn = connect(database="dbname", user="user",
> password="password",host="127.0.0.1")
> logging.info <http://logging.info>("database connected")
> conn.autocommit = True
> conn.set_client_encoding('UTF8')
> cur = conn.cursor()
> #the above code executed without exception
> #and [server closed the connection unexpectedly] thrown when any
> cur.execute() called
> I think it's strange because the server reset connection after
> connected,and the connect function should throw a exception.

You sure you are not doing anything contrary to the instructions here:

http://initd.org/psycopg/docs/usage.html#thread-safety

>
> It's nothing in the log file.
>
> Thanks.
>
--
Adrian Klaver
adrian.klaver@gmail.com

On Fri, Nov 2, 2012 at 1:57 PM, Dongkuo Ma <luc.mdk@gmail.com> wrote:
> Hi
> the python code is
>
> logging.info("database connecting...")
> conn = connect(database="dbname", user="user",
> password="password",host="127.0.0.1")
> logging.info("database connected")
> conn.autocommit = True
> conn.set_client_encoding('UTF8')
> cur = conn.cursor()
> #the above code executed without exception
> #and [server closed the connection unexpectedly] thrown when any
> cur.execute() called
> I think it's strange because the server reset connection after connected,and
> the connect function should throw a exception.
>
> It's nothing in the log file.

Is there a long delay between connecting and executing a query? It may
be that something disconnected you during that time. Or could the
server have been restarted?

Can you make a simple Python script that always fails in this way?

Chris Angelico

On Fri, Nov 2, 2012 at 2:43 PM, Dongkuo Ma <luc.mdk@gmail.com> wrote:
> I connect to database and then fork a new process!
> Now it's ok.
> Thanks.

Ah, yes, that would be a dangerous thing to do :)

ChrisA