follow_master_command = '/path/to/pgpool_follow_master.sh %d %h %H %r %R'

pgpool_follow_master.sh

#!/bin/bash

set -e

SSH=/usr/bin/ssh
PGCTL=/usr/bin/pg_ctl
PCP_ATTACH_NODE=/usr/sbin/pcp_attach_node
DEVNULL=/dev/null

if [ -z "$PCP_HOST" ]; then
  PCP_HOST=localhost
fi

if [ -z "$PCP_PORT" ]; then
  PCP_PORT=9898
fi

if [ -z "$PCP_USER" ]; then
  PCP_USER=your_pcp_account
fi

if [ -z "$PCP_PASSWORD" ]; then
  PCP_PASSWORD=your_pcp_pass
fi

if [ -z "$REPLICATION_USER" ]; then
  REPLICATION_USER=replication
fi

if [ $# != 5 ]; then
  echo "Usage: $(basename $0) failed_node failed_host new_master new_master_port cluster_path" >&2
  exit 1
fi

failed_node=$1
failed_host=$2
new_master=$3
new_master_port=$4
cluster_path=$5

recovery_conf=$cluster_path/recovery.conf

# Do nothing if standby goes down.
if [ $failed_node = 0 -o $failed_node = 1 ]; then
  echo "node number:$failed_node is not target node number. skip"
  exit 0;
fi

# execute new master restart
$SSH -T $new_master "$PGCTL restart -w -m fast -D $cluster_path >$DEVNULL 2>&1 <$DEVNULL"
echo "$new_master postgres restart. ok"

# make recovery.conf for slave host
cat <<EOL | $SSH -T $failed_host "cat >$recovery_conf"
standby_mode = 'on'
primary_conninfo = 'host=$new_master port=$new_master_port user=$REPLICATION_USER application_name=$failed_host'
trigger_file = '$cluster_path/trigger_file'
recovery_target_timeline='latest'
restore_command = '/bin/cp /data/pgsql/archlog/%f "%p"'
archive_cleanup_command = 'pg_archivecleanup /data/pgsql/archlog %r'
EOL
echo "make recovery.conf for $failed_host. ok"

# execute slave restart
$SSH -T $failed_host "$PGCTL restart -w -m fast -D $cluster_path >$DEVNULL 2>&1 <$DEVNULL"
echo "$failed_host postgres restart. ok"

# attach failed node
$PCP_ATTACH_NODE 0 $PCP_HOST $PCP_PORT $PCP_USER $PCP_PASSWORD $failed_node
echo "pcp_attach_node:$failed_node. ok"