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Cron DB Bounce causes index problems && Help rotating logs

From: "Chris Hoover" <revoohc(at)sermonaudio(dot)com>
To: <pgsql-admin(at)postgresql(dot)org>
Subject: Cron DB Bounce causes index problems && Help rotating logs
Date: 2005-01-14 15:16:52
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-admin
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.



Here is the cron line:
01 20 * * * /pgsql/tmp/bin/ 50001

Here is the script:

source ~postgres/etc/dba.profile



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 ]
  echo "POSTGRES DID NOT STOP" | mail -s "`hostname` stop fail" $DBAPAGER

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 ]
  echo "POSTGRES DID NOT START" | mail -s "`hostname` start fail" $DBAPAGER

echo "`date` - `hostname` - log rotation finished" | mail -s "`hostname` rotation" $DBAPAGER

Here is the dba.profile file:
DBAPAGER=<my pager number>






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