Thread: lots of puzzling log messages
I am Seeing twelve of these messages every five to ten seconds in the Postgresql serverlog when my java application is running: 2005-04-19 16:43:03 LOG: 00000: duration: 0.246 ms LOCATION: exec_simple_query, postgres.c:960 2005-04-19 16:43:03 LOG: 00000: statement: rollback; begin; LOCATION: pg_parse_query, postgres.c:464 postgresql.conf has: log_connections = true log_duration = true log_statement = true log_timestamp = true Running postgres 7.4.2. The Java application uses postgresql-7.4.1.jar. It is a custom developed application. I am wondering what these log messages mean. Any ideas? Dennis
On Tue, Apr 19, 2005 at 05:39:42PM -0700, Dennis Sacks wrote: > > I am Seeing twelve of these messages every five to ten seconds in the > Postgresql serverlog when my java application is running: > > 2005-04-19 16:43:03 LOG: 00000: duration: 0.246 ms > LOCATION: exec_simple_query, postgres.c:960 > 2005-04-19 16:43:03 LOG: 00000: statement: rollback; begin; > LOCATION: pg_parse_query, postgres.c:464 Looks like the application is aborting its transaction (rollback) and starting a new one (begin). If you're not doing this explicitly then the API is probably doing it under the hood. If you're logging queries then you should be able to figure out where this is happening in the application. -- Michael Fuhr http://www.fuhr.org/~mfuhr/
Michael Fuhr <mike@fuhr.org> writes:
> On Tue, Apr 19, 2005 at 05:39:42PM -0700, Dennis Sacks wrote:
>> I am Seeing twelve of these messages every five to ten seconds in the
>> Postgresql serverlog when my java application is running:
>>
>> 2005-04-19 16:43:03 LOG: 00000: duration: 0.246 ms
>> LOCATION: exec_simple_query, postgres.c:960
>> 2005-04-19 16:43:03 LOG: 00000: statement: rollback; begin;
>> LOCATION: pg_parse_query, postgres.c:464
> Looks like the application is aborting its transaction (rollback)
> and starting a new one (begin). If you're not doing this explicitly
> then the API is probably doing it under the hood.
I think older versions of the JDBC driver will do that behind your back
... try the latest driver, and if you still see it then inquire on
pgsql-jdbc.
regards, tom lane
On Wed, 20 Apr 2005, Tom Lane wrote: > > On Tue, Apr 19, 2005 at 05:39:42PM -0700, Dennis Sacks wrote: > >> I am Seeing twelve of these messages every five to ten seconds in the > >> Postgresql serverlog when my java application is running: > >> > >> 2005-04-19 16:43:03 LOG: 00000: statement: rollback; begin; > >> LOCATION: pg_parse_query, postgres.c:464 > > I think older versions of the JDBC driver will do that behind your back > ... try the latest driver, and if you still see it then inquire on > pgsql-jdbc. The latest driver will do that as well, but in two statements now that transaction end doesn't automatically start a new one immediately. The difference is that the server doesn't log it for the 8.0 driver because it prepares the begin/commit/rollback statements just once and executes them from then on. Kris Jurka
Kris Jurka <books@ejurka.com> writes:
> The latest driver will do that as well, but in two statements now that
> transaction end doesn't automatically start a new one immediately. The
> difference is that the server doesn't log it for the 8.0 driver because
> it prepares the begin/commit/rollback statements just once and executes
> them from then on.
Hmm. ISTM the value of preparing a utility statement like begin/commit/
rollback would be minuscule at best. Is there a reason for not just
issuing those as plain queries?
regards, tom lane