Обсуждение: Cron-job for checking up on pg_autovacuum

Hi!

I haven't found anything in terms of startup- and check-scripts for
pg_autovacuum yet; usually I like to have some sort of mechanism to
check if some daemon is running and restart it if it isn't.

Of course this sort of script shouldn't be too much of a bother for more
experienced users; however you might actually find this small
checkup-script more or less useful - just save it in /opt/pgsql/bin/ as
autovachk, chmod +x and follow the included instructions for adding it
to your crontab.

Regards

    Markus

#!/bin/sh
#
# This is a script suitable for use in a crontab.  It checks to make
sure
# your pg_autovacuum daemon is running.
#
# To check for the daemon every 5 minutes, put the following line in
your
# crontab:
#    2,7,12,17,22,27,32,37,42,47,52,57 * * * *
#      /opt/pgsql/bin/autovachk >/dev/null 2>&1

# change this to the directory you run the daemon from:
dir="/opt/pgsql/bin"

# change this to the complete commandline you usually start the daemon
with
daemoninvoc="pg_autovacuum -D -U postgres -L /var/log/pgautovac.log"

# I wouldn't touch this if I were you.
daemonpid=`eval ps ax | sed -n '/[p]g_autovacuum/p' | awk '{ print $1
}'`
########## you probably don't need to change anything below here
##########

cd $dir
if `kill -CHLD $daemonpid >/dev/null 2>&1`; then
  # it's still going, so back out quietly
  exit 0
fi
echo ""
echo "Couldn't find the pg_autovacuum daemon running.  Reloading it..."
echo ""
./$daemoninvoc
sleep 3

Markus Wollny wrote:

>Hi!
>
>I haven't found anything in terms of startup- and check-scripts for
>pg_autovacuum yet; usually I like to have some sort of mechanism to
>check if some daemon is running and restart it if it isn't.
>
>

Agreed, this needs to be improved.  In the long term, pg_autovacuum
should be started and stopped with the postmaster.  However, as it is a
contrib module right now, it won't happen.

I know I heard from at least one person who said they were running it
from there inittab with respawn, which seems like overkill.

On Tue, 2003-11-25 at 02:13, Markus Wollny wrote:
> Hi!
>
> I haven't found anything in terms of startup- and check-scripts for
> pg_autovacuum yet; usually I like to have some sort of mechanism to
> check if some daemon is running and restart it if it isn't.

The Debian package of 7.4 starts pg_autovacuum in the rc script if it is
so configured.

--
Oliver Elphick                                Oliver.Elphick@lfix.co.uk
Isle of Wight, UK                             http://www.lfix.co.uk/oliver
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                 ========================================
     "Who shall ascend into the hill of the LORD? or who
      shall stand in his holy place? He that hath clean
      hands, and a pure heart..."            Psalms 24:3,4

When grilled further on (Tue, 25 Nov 2003 11:19:32 -0500),
"Matthew T. O'Connor" <matthew@zeut.net> confessed:

> I know I heard from at least one person who said they were running it
> from there inittab with respawn, which seems like overkill.

Nah, it works great (it was me).  I just had an unclean shutdown/reboot, and
pg_autovacuum couldn't connect on start because PGSQL was coming up.  inittab
took note of the quick respawning and put a 5 minute delay in there.  And I got
to ignore it.

Also works great when PGSQL is down for any reason.  You don't have to worry
about stopping/starting pg_autovacuum...

Overkill is a good thing!  It keeps stuff working ;-)

Cheers,
Rob

my /etc/inittab line (Mandrake 9.1 system)

vac:235:respawn:su - postgres -c "/usr/local/pgsql/bin/pg_autovacuum -d 0"

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