Re: Warm-Backup configuration question - Mailing list pgsql-admin

You need to make the script wait forever for the next archive file, or
return 1 only if you want to complete the recovery.  Here's a stub of
what we do:

#!/usr/bin/ksh

set -e

# Where copy.sh fetches WALs from
ARCHDIR=/data3/archive_log

# Name of log file that copy.sh writes to
copy_log=copy.log
# Name of stop file that copy looks for to signal "go live"
copy_stop=copy.stop

# How many seconds sleep between copy iterations
seconds=15
# Expected size of WAL file
size=16777216

src=$1
dest=$2
base=$(basename $src)

exec >>$copy_log
exec 2>&1

echo $base

case $base in
     *.history)
         echo "\tignored"
         exit 1
         ;;
     *.backup)
         size=+0
         ;;
esac


while :; do

     if [ -f $copy_stop ]; then
         echo "\tstop file"
         rm $copy_stop
         exit 1
     fi

     if [ -f "$src" ]; then
         if [ "$(find $src -size ${size}c)" ]; then

             echo "\tfound"
             cp $src $dest

             exit 0
         else
             echo "\ttoo small"
         fi
     fi

     echo "\tsleeping $seconds"
     sleep $seconds
done


Kenji Morishige wrote:
> I've got 2 identical servers configured exactly the same way, except for some
> minor differences for the WAL logging directories.  I have both machines set up
> as a NFS server and client, so that the WAL archive gets written out to the
> local filesystem of the backup machine depending on which role the machine is
> currently configured for.
>
> I've been able to get the backup server syncronized by using the recover.conf
> file as described in the documenation, but I can't seem to write a generic shell
> script that will keep the warm-backup in a continously syncronizing mode.  It
> always stops and renames the recover.conf to recover.done.
>
> I've tried to write an alternate restore command as follows:
>
> #!/usr/local/bin/bash
> if [ -e /export/raid/pgsql/recovery.stop ]; then
>   exit 1
> fi
> if [ -e $1 ]; then
>   `/bin/cp $1 $2`
> fi
> sleep 5
> exit 0
>
> The documenation says that it should return 0 only if it is successfull.  My
> understanding is that the recovery script should continuously try to copy the
> archived data to the WAL directory so that the WARM-BACKUP server can
> syncronize.  I'd like to have the WARM-BACKUP always be only a few minutes
> behind in syncronization from the PRIMARY without human intervention. I can
> write a cronjob to clean out the WAL archive directory accordingly.
>
> I would be extremely gratefull for any assistance from anyone with a similar
> configuration.  I must be confused by how the restore_command is supposed to
> work.
>
> Sincerely,
> Kenji
>
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