Hi all,
We are having an issue here trying to automate our db log rotations. We were
using the Apache rotatelogs program and we thought it was working fine.
However, when we had a server crash and had to recover and roll forward using
the postgresql logs (we are logging all sql), we discovered that some of the
sql records in the log were being over written. This has caused us to go back
to just having postgresql log directly to the drives. (The problem with
rotatelogs looked like this "[2005-01-14 08:00:01] [123] LOG: query: select *
fr[2005-01-14 08:00:01] ....")
Anyway, we are now manually rotating the logs. We tried to rotate the logs via
a simple script and cron, but we ended up causing strange index issues. The
data would be in the tables and would show if a table scan was forced. But
many tables would not show the data if an index scan (esp. if the primary key
was used) was used. We also had issues with system allowing records to be
inserted that violated the primary key.
Manually logging into the servers and running the same script from the shell
prompt works fine and does not cause any index issues.
Any ideas on what is going on here? We do not have any postgresql related
environmental variables set in the shell. Do we need to execute a db bounce
via cron with a "special" call from cron?
Also, has anyone else seen the rotatelogs issue?
Is there a better way to rotate the logs w/o bouncing the db every night? Due
to recovery requirements, we must have the sql logged to the postgresql log.
These logs grow to between 2 and 5 GB every day. Running for more than 2 days
without rotating the logs tends to cause a noticable slowdown to our users.
Any help would be appreciated.
Chris
P.S.
Here is the cron line:
01 20 * * * /pgsql/tmp/bin/rotate_logs.sh 50001
Here is the rotate_log.sh script:
source ~postgres/etc/dba.profile
PORT=$1
LOGPATH=${LOG_PATH}/${PORT}/pg_log
echo "`date` - `hostname` - log rotation started" | mail -s "`hostname`
rotation" $DBAPAGER
## shutdown the database
${POSTGRES_BIN}/pg_ctl -D ${DB_PATH}/${PORT} -m fast stop >
~postgres/db_${PORT}_stop.log 2>&1
STOPPED=`cat ~postgres/db_${PORT}_stop.log | grep "postmaster successfully shut
down" | wc -l`
if [ $STOPPED != 1 ]
then
echo "POSTGRES DID NOT STOP" | mail -s "`hostname` stop fail" $DBAPAGER
exit
fi
sleep 150
mv $LOGPATH/postgres.log $LOGPATH/postgres.log.`date +%m%d%y%H%M`
sleep 150
${POSTGRES_BIN}/pg_ctl -D ${DB_PATH}/${PORT} -l ${LOGPATH}/postgres.log start >
~postgres/db_${PORT}_start.log 2>&1
STARTED=`grep "successfully start" ~postgres/db_${PORT}_start.log | wc -l `
if [ $STARTED != 1 ]
then
echo "POSTGRES DID NOT START" | mail -s "`hostname` start fail" $DBAPAGER
fi
echo "`date` - `hostname` - log rotation finished" | mail -s "`hostname`
rotation" $DBAPAGER
Here is the dba.profile file:
DBAPAGER=<my pager number>
POSTGRES=/pgsql/
POSTGRES_BIN=${POSTGRES}/bin
DB_PATH=/data
LOG_PATH=/data
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TIP 4: Don't 'kill -9' the postmaster
