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首页 / PGPOOL部署安装，高可用切换测试

PGPOOL部署安装，高可用切换测试

原创 向前龙 2021-11-24
4425

一，简介

https://www.modb.pro/db/176706

二，pgpool PCP命令集

pcp_detach_node - 将给定节点从 Pgpool-II 分离。与Pgpool-II的外泄连接被迫断开。
pcp_attach_node - 将给定的节点连接到 Pgpool-II。
pcp_stop_pgpool - 终止Pgpool-II进程
pcp_reload_config - 重新加载 pgpool-II 配置文件
pcp_recovery_node - 将给定的后端节点与恢复连接

三，pgpool脚本样本

image.png

故障转移脚本介绍

image.png
failover_command触发条件：
1，health check(网络问题或者pg无法工作)
2，若没有连接链接到pgpool，
则pg关闭不会触发
脚本逻辑
1，如果是从库down
那么在主库上drop replication slot
2，如果是主库down 那么提升从库为新主

image.png
follow_primary_command触发条件
1，在主节点故障转移后要运行的用户命令
2，pcp_promote_node命令
(仅在流复制模式下有效)
脚本逻辑
同步从库到新主
1，pg_rewind
2，pg_basebackup（pcp_recovery_node）

四，pgpool部署

image.png
端口规划：

image.png

在100/101/102上关闭防火墙和selinux：

[root@allserver ~]# systemctl disable firewalld
[root@allserver ~]# systemctl stop firewalld
[root@allserver ~]# setenforce 0
[root@allserver ~]# sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/confi

安装/配置 pgpool：

[root@allserver src]# tar -zxf pgpool-II-4.2.4.tar.gz
[root@allserver pgpool-II-4.2.4]# ./configure --prefix=/usr/local/pgpool
[root@allserver pgpool-II-4.2.4]# make && make install 
[root@allserver pgpool-II-4.2.4]# cd  /usr/local/pgpool/etc
[root@allserver etc]# cp pcp.conf.sample pcp.conf;cp pgpool.conf.sample-stream pgpool.conf;
cp follow_primary.sh.sample follow_primary.sh; chmod +x failover.sh;cp failover.sh.sample failover.sh; chmod +x failover.sh;
cp escalation.sh.sample escalation.sh;chmod +x escalation.sh;
chown postgres:postgres /usr/local/pgpool/etc/{failover.sh,follow_primary.sh,escalation.sh};
cp recovery_1st_stage.sample recovery_1st_stage;chmod +x recovery_1st_stage;
mv recovery_1st_stage /data/pg_data/;cp pgpool_remote_start.sample pgpool_remote_start;
chmod +x pgpool_remote_start;mv pgpool_remote_start /data/pg_data/;chown postgres:
postgres /data/pg_data -R;cp pool_hba.conf.sample pool_hba.conf;
echo "export  PATH=\$PATH:/usr/local/pgpool/bin/">> /etc/profile; . /etc/profile

设置密码

[root@allserver etc]# pg_md5 -p -m -u postgres pool_passwd
password: (输入密码123qwert)
[root@allserver etc]# pg_md5 -p -m -u pgpool pool_passwd
password: (输入密码123qwert)
[root@allserver etc]# cat /usr/local/pgpool/etc/pool_passwd 
postgres:md569d08236c8e9fc9e0fd97e9d74afe7de
pgpool:md560cd0c52f2f43bb1eb5f18c70ae85a59

修改：

[postgres@allserver ~]$ vim /usr/local/pgpool/etc/failover.sh
PGHOME=/usr/local/pgsql

/data/pg_data/recovery_1st_stage脚本内容：
[postgres@allserver pgpool_logs]$ vim  /data/pg_data/recovery_1st_stage
PGHOME=/usr/local/pgsql/
ARCHIVEDIR=/data/pg_archive/
REPLUSER=replic

在53行左右的pg_basebackup的后面加上-R参数
image.png

以及第56行左右的.pgpass文件路径由/var/lib/pgsql/.pgpass更改为 ~/.pgpass
image.png

修改/data/pg_data/pgpool_remote_start里面的内容

PGHOME=/usr/local/pgsql/

修改/usr/local/pgpool/etc/follow_primary.sh里面内容

#!/bin/bash
# This script is run after failover_command to synchronize the Standby with the new Primary.
# First try pg_rewind. If pg_rewind failed, use pg_basebackup.

set -o xtrace
# Special values:
# 1)  %d = node id
# 2)  %h = hostname
# 3)  %p = port number
# 4)  %D = node database cluster path
# 5)  %m = new primary node id
# 6)  %H = new primary node hostname
# 7)  %M = old main node id
# 8)  %P = old primary node id
# 9)  %r = new primary port number
# 10) %R = new primary database cluster path
# 11) %N = old primary node hostname
# 12) %S = old primary node port number
# 13) %% = '%' character

NODE_ID="$1"
NODE_HOST="$2"
NODE_PORT="$3"
NODE_PGDATA="$4"
NEW_PRIMARY_NODE_ID="$5"
NEW_PRIMARY_NODE_HOST="$6"
OLD_MAIN_NODE_ID="$7"
OLD_PRIMARY_NODE_ID="$8"
NEW_PRIMARY_NODE_PORT="$9"
NEW_PRIMARY_NODE_PGDATA="${10}"

FAILED_NODE_ID="$1"
FAILED_NODE_HOST="$2"
FAILED_NODE_PORT="$3"
FAILED_NODE_DATA="$4"
NEW_MASTER_NODE_ID="$5"
NEW_MASTER_NODE_HOST="$6"
OLD_MASTER_NODE_ID="$7"
OLD_PRIMARY_NODE_ID="$8"
NEW_MASTER_NODE_PORT="$9"
NEW_MASTER_NODE_PGDATA="${10}"
OLD_PRIMARY_NODE_HOST="${11}"
OLD_PRIMARY_NODE_PORT="${12}"

PGHOME=/usr/local/pgsql/
ARCHIVEDIR=/data/pg_archive
REPLUSER=replic
PCP_USER=pgpool
PGPOOL_PATH=/usr/local/pgpool/bin/
PCP_PORT=9898
REPL_SLOT_NAME=${NODE_HOST//[-.]/_}

#超级用户
PGUSER_SUPER=postgres
#超级用户pgdb密码
PGUSER_SUPER_PWD='123qwert'
#dbname
PGUSER_SUPER_DBNAME=postgres

#复制用户
PGUSER_REPLI=replic
#复制用户密码
PGUSER_REPLI_PWD='123qwert'

echo follow_primary.sh: start: Standby node ${FAILED_NODE_ID}

## Get PostgreSQL major version
PGVERSION=`${PGHOME}/bin/initdb -V | awk '{print $3}' | sed 's/\..*//' | sed 's/\([0-9]*\)[a-zA-Z].*/\1/'`

if [ $PGVERSION -ge 12 ]; then
    RECOVERYCONF=${FAILED_NODE_DATA}/myrecovery.conf
else
    RECOVERYCONF=${FAILED_NODE_DATA}/recovery.conf
fi

## Test passwrodless SSH
ssh -T -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null $PGUSER_SUPER@${NEW_PRIMARY_NODE_HOST} -i ~/.ssh/id_rsa_pgpool ls /tmp > /dev/null

if [ $? -ne 0 ]; then
    echo follow_main.sh: passwrodless SSH to $PGUSER_SUPER@${NEW_PRIMARY_NODE_HOST} failed. Please setup passwrodless SSH.
    exit 1
fi

## Check the status of Standby
ssh -T -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null \
$PGUSER_SUPER@${FAILED_NODE_HOST} -i ~/.ssh/id_rsa_pgpool ${PGHOME}/bin/pg_ctl -w -D ${FAILED_NODE_DATA} status

## If Standby is running, synchronize it with the new Primary.
if [ $? -eq 0 ]; then

    echo follow_primary.sh: pg_rewind for node ${FAILED_NODE_ID}

    # Create replication slot "${REPL_SLOT_NAME}"
    echo 'this is create_physical_replication_slot-->'${REPL_SLOT_NAME}
    ${PGHOME}/bin/psql -h ${NEW_PRIMARY_NODE_HOST} -p ${NEW_PRIMARY_NODE_PORT} \
        -c "SELECT pg_create_physical_replication_slot('${REPL_SLOT_NAME}');"  >/dev/null 2>&1

    if [ $? -ne 0 ]; then
        echo follow_primary.sh: create replication slot \"${REPL_SLOT_NAME}\" failed. You may need to create replication slot manually.
    fi

    ssh -T -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null $PGUSER_SUPER@${FAILED_NODE_HOST} -i ~/.ssh/id_rsa_pgpool "

        set -o errexit

        ${PGHOME}/bin/pg_ctl -w -m f -D ${FAILED_NODE_DATA} stop

        ${PGHOME}/bin/pg_rewind -R -D ${FAILED_NODE_DATA} --source-server=\"user=$PGUSER_SUPER host=${NEW_PRIMARY_NODE_HOST} port=${NEW_PRIMARY_NODE_PORT}\"

        rm -rf ${FAILED_NODE_DATA}/pg_replslot/*

    cat > ${RECOVERYCONF} << EOT
primary_conninfo = 'host=${NEW_PRIMARY_NODE_HOST} port=${NEW_PRIMARY_NODE_PORT} user=${REPLUSER} application_name=${FAILED_NODE_HOST} user=$PGUSER_REPLI password=$PGUSER_REPLI_PWD'
recovery_target_timeline = 'latest'
restore_command = 'scp ${NEW_PRIMARY_NODE_HOST}:${ARCHIVEDIR}/%f %p'
primary_slot_name = '${REPL_SLOT_NAME}'
EOT
        if [ ${PGVERSION} -ge 12 ]; then
            sed -i -e \"\\\$ainclude_if_exists = '$(echo ${RECOVERYCONF} | sed -e 's/\//\\\//g')'\" \
                   -e \"/^include_if_exists = '$(echo ${RECOVERYCONF} | sed -e 's/\//\\\//g')'/d\" ${FAILED_NODE_DATA}/postgresql.auto.conf
            touch ${FAILED_NODE_DATA}/standby.signal
        else
            echo \"standby_mode = 'on'\" >> ${RECOVERYCONF}
        fi
"
sleep 2
ssh -T -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null $PGUSER_SUPER@${FAILED_NODE_HOST} -i ~/.ssh/id_rsa_pgpool "
        ${PGHOME}/bin/pg_ctl -l /dev/null -w -D ${FAILED_NODE_DATA} restart -mf 
    "
    if [ $? -ne 0 ]; then
      echo 'pg_rewind is failed ,will try to use pcp_recovery_node'
      ssh -i ~/.ssh/id_rsa_pgpool -T $FAILED_NODE_HOST "${PGPOOL_PATH}/pcp_recovery_node -h NEW_MASTER_NODE_HOST -v -p $PGPOOL_PORT -U $PGUSER_SUPER -n $FAILED_NODE_ID "
      sleep 2
      ssh -i ~/.ssh/id_rsa_pgpool -T $FAILED_NODE_HOST "${PGPOOL_PATH}/pcp_recovery_node -h FAILED_NODE_HOST -v -p $PGPOOL_PORT -U $PGUSER_SUPER -n $FAILED_NODE_ID "
      if [ $? -ne 0 ]; then
       echo 'the old primary pg_rewind and pcp_recovery_node is failed!'
      fi
    fi
   # If start Standby successfully, attach this node
    ssh -T -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null $PGUSER_SUPER@${FAILED_NODE_HOST} -i ~/.ssh/id_rsa_pgpool $PGHOME/bin/pg_ctl -w -D /data/pg_data status
    if [ $? -eq 0 ]; then

        # Run pcp_attact_node to attach Standby node to Pgpool-II.
       echo "pgpool_follow_master pcp_attach_node 111 id-->"${FAILED_NODE_ID} 
       ${PGPOOL_PATH}/pcp_attach_node -w -h $NEW_MASTER_NODE_HOST -U $PCP_USER -p ${PCP_PORT} -n ${FAILED_NODE_ID}

       if [ $? -ne 0 ]; then
        ssh -i ~/.ssh/id_rsa_pgpool -T $NEW_MASTER_NODE_HOST "${PGPOOL_PATH}/pcp_attach_node  -d -w -h $NEW_MASTER_NODE_HOST -p $PCP_PORT -U $PGUSER_SUPER -n $FAILED_NODE_ID "
       fi
       if [ $? -ne 0 ]; then
        ssh -i ~/.ssh/id_rsa_pgpool -T $NEW_MASTER_NODE_HOST "${PGPOOL_PATH}/pcp_attach_node  -d -w -h $FAILED_NODE_HOST -p $PCP_PORT -U $PGUSER_SUPER -n $FAILED_NODE_ID "
       fi

        if [ $? -ne 0 ]; then
                echo ERROR: follow_primary.sh: end: pcp_attach_node failed
                exit 1
        fi
   # If start Standby failed, drop replication slot "${REPL_SLOT_NAME}"
    else

        ${PGHOME}/bin/psql -h ${NEW_PRIMARY_NODE_HOST} -p ${NEW_PRIMARY_NODE_PORT} \
            -c "SELECT pg_drop_replication_slot('${REPL_SLOT_NAME}');"  >/dev/null 2>&1

        if [ $? -ne 0 ]; then
            echo ERROR: follow_primary.sh: drop replication slot \"${REPL_SLOT_NAME}\" failed. You may need to drop replication slot manually.
        fi

        echo ERROR: follow_primary.sh: end: follow primary command failed
        exit 1
    fi

else
    echo "follow_primary.sh: failed_nod_id=${FAILED_NODE_ID} is not running. try to fix it"
    ###对失败的数据节点尝试操作####################### start 
    echo '对失败的数据节点尝试操作--start'
    echo "pgpool_follow_master stop pgdb "
    ssh -i ~/.ssh/id_rsa_pgpool -T $FAILED_NODE_HOST "${PGHOME}/bin/pg_ctl stop -m fast -D $FAILED_NODE_DATA"
    echo "failover.sh: failed_node_id=$FAILED_NODE_ID failed_node_host=${FAILED_NODE_HOST} stop The action has been completed!"
#    echo "pgpool_follow_master pg_rewind pgdb "
#    ssh -i ~/.ssh/id_rsa_pgpool -T $FAILED_NODE_HOST "${PGHOME}/bin/pg_rewind --target-pgdata=$FAILED_NODE_DATA --source-server='host=$NEW_MASTER_NODE_HOST port=$NEW_MASTER_NODE_PORT user=$PGUSER_SUPER password=$PGUSER_SUPER_PWD dbname=$PGUSER_SUPER_DBNAME' -P -R"
    echo "pgpool_follow_master touch the FAILED_NODE_ID:${FAILED_NODE_ID} pgdb conf file ${PGRECOVERYCONF}"
   # Create replication slot "${REPL_SLOT_NAME}"

 echo 'this is start create replication'${REPL_SLOT_NAME}
    ${PGHOME}/bin/psql -h ${NEW_PRIMARY_NODE_HOST} -p ${NEW_PRIMARY_NODE_PORT} \
        -c "SELECT pg_create_physical_replication_slot('${REPL_SLOT_NAME}');"  >/dev/null 2>&1

    if [ $? -ne 0 ]; then
        echo follow_primary.sh: create replication slot \"${REPL_SLOT_NAME}\" failed. You may need to create replication slot manually.
    fi

echo "pgpool_follow_master pg_rewind pgdb "
    ssh -T -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null $PGUSER_SUPER@${FAILED_NODE_HOST} -i ~/.ssh/id_rsa_pgpool "
        set -o errexit
        ${PGHOME}/bin/pg_rewind -R -D ${FAILED_NODE_DATA} --source-server=\"user=$PGUSER_SUPER host=${NEW_PRIMARY_NODE_HOST} port=${NEW_PRIMARY_NODE_PORT}\"

        rm -rf ${FAILED_NODE_DATA}/pg_replslot/*
       cat > ${RECOVERYCONF} << EOT
primary_conninfo = 'host=${NEW_PRIMARY_NODE_HOST} port=${NEW_PRIMARY_NODE_PORT} user=${REPLUSER} application_name=${FAILED_NODE_DATA} user=$PGUSER_REPLI password=$PGUSER_REPLI_PWD'
recovery_target_timeline = 'latest'
restore_command = 'scp ${NEW_PRIMARY_NODE_HOST}:${ARCHIVEDIR}/%f %p'
primary_slot_name = '${REPL_SLOT_NAME}'
EOT

    if [ ${PGVERSION} -ge 12 ]; then
            sed -i -e \"\\\$ainclude_if_exists = '$(echo ${RECOVERYCONF} | sed -e 's/\//\\\//g')'\" \
                   -e \"/^include_if_exists = '$(echo ${RECOVERYCONF} | sed -e 's/\//\\\//g')'/d\" ${FAILED_NODE_DATA}/postgresql.auto.conf
            touch ${FAILED_NODE_DATA}/standby.signal
        else
           echo \"standby_mode = 'on'\" >> ${RECOVERYCONF}
        fi
"
    sleep 2
    echo "pgpool_follow_master start pgdb "
    ssh -i ~/.ssh/id_rsa_pgpool -T $FAILED_NODE_HOST "${PGHOME}/bin/pg_ctl  start -D $FAILED_NODE_DATA 2>/dev/null 1>/dev/null < /dev/null &"
    #####################################  如果pg_rewind失败进行recovery操作 -- start
    if [ $? -ne 0 ]; then
     ssh -i ~/.ssh/id_rsa_pgpool -T $FAILED_NODE_HOST "${PGPOOL_PATH}/pcp_recovery_node -h NEW_MASTER_NODE_HOST -v -p $PGPOOL_PORT -U $PGUSER_SUPER -n $FAILED_NODE_ID "
    sleep 2
     ssh -i ~/.ssh/id_rsa_pgpool -T $FAILED_NODE_HOST "${PGPOOL_PATH}/pcp_recovery_node -h FAILED_NODE_HOST -v -p $PGPOOL_PORT -U $PGUSER_SUPER -n $FAILED_NODE_ID "
     if [ $? -ne 0 ]; then
      echo 'the old primary pg_rewind and pcp_recovery_node is failed!'
     fi
    fi
    #####################################  如果pg_rewind失败进行recovery操作 -- end
    sleep 2

    echo "pgpool_follow_master pcp_attach_node 222  id->"${FAILED_NODE_ID}
    ${PGPOOL_PATH}/pcp_attach_node -w -h $NEW_MASTER_NODE_HOST -U $PCP_USER -p ${PCP_PORT} -n ${FAILED_NODE_ID}
    sleep 2
    ssh -i ~/.ssh/id_rsa_pgpool -T $NEW_MASTER_NODE_HOST "${PGPOOL_PATH}/pcp_attach_node  -d -w -h $NEW_MASTER_NODE_HOST -p $PCP_PORT -U $PGUSER_SUPER -n $FAILED_NODE_ID "
    sleep 2
    ssh -i ~/.ssh/id_rsa_pgpool -T $FAILED_NODE_HOST "${PGPOOL_PATH}/pcp_attach_node  -d -w -h $FAILED_NODE_HOST -p $PCP_PORT -U $PGUSER_SUPER -n $FAILED_NODE_ID "
    echo "pgpool_follow_master exit 0 "
    echo '对失败的数据节点尝试操作--start'
    ###对失败的数据节点尝试操作####################### end
    exit 0
fi

echo follow_primary.sh: end: follow primary command is completed successfully
exit 0

修改 $VIP/24为$VIP/20 掩码;并且修改vip；以及DEVICE配置为机器自己的网卡

[root@allserver etc]# vim escalation.sh

set -o xtrace
PGPOOLS=(server1 server2 server3)

VIP=192.168.254.99
DEVICE=ens33

for pgpool in "${PGPOOLS[@]}"; do
    [ "$HOSTNAME" = "$pgpool" ] && continue

    ssh -T -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null postgres@$pgpool -i ~/.ssh/id_rsa_pgpool "
        /usr/bin/sudo /sbin/ip addr del $VIP/20 dev $DEVICE
    "
done

exit 0

如果某一个网卡名称不一样，需要另外处理：
[postgres@server1 ~]$ vim /usr/local/pgpool/etc/escalation.sh

#!/bin/bash
# This script is run by wd_escalation_command to bring down the virtual IP on other pgpool nodes
# before bringing up the virtual IP on the new active pgpool node.

set -o xtrace

PGPOOLS=(server1 server2 server3)

VIP=192.168.254.99
DEVICE=ens33
DEVICE2=eth0

for pgpool in "${PGPOOLS[@]}"; do
    [ "$HOSTNAME" = "$pgpool" ] && continue
    if [[ $pgpool != 'server2' ]]
    then
    ssh -T -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null postgres@$pgpool -i ~/.ssh/id_rsa_pgpool "
        /usr/bin/sudo /sbin/ip addr del $VIP/20 dev $DEVICE
    "
   else
    ssh -T -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null postgres@$pgpool -i ~/.ssh/id_rsa_pgpool "
         /usr/bin/sudo /sbin/ip addr del $VIP/20 dev $DEVICE2
    "
  fi
done
exit 0

配置postgres用户的sudo权限：

[root@allserver etc]# cat /etc/sudoers |grep postgres
postgres ALL=(ALL)       NOPASSWD:ALL

配置目录：

[root@allserver etc]# mkdir /runpg;mkdir /runpg/pgpool_log/;mkdir /runpg/pgpool ;mkdir /runpg/postgres  ; chown postgres:postgres /runpg -R

#enable_pool_hba = on

[all servers]# vi /usr/local/pgpool/etc/pool_hba.conf
# 官方文档为 scram-sha-256，改为md5
host    all         pgpool           0.0.0.0/0          md5
host    all         postgres         0.0.0.0/0          md5

修改pgpool.conf相关配置
[root@localhost etc]# vim pgpool.conf

# [CONNECTIONS]
listen_addresses = '*'
port = 9999
socket_dir = '/runpg/postgresql'
pcp_socket_dir = '/runpg/postgres'
## - Backend Connection Settings -
backend_hostname0 = 'server1'
backend_port0 = 5432
backend_weight0 = 1
backend_data_directory0 = '/data/pg_data'
backend_flag0 = 'ALLOW_TO_FAILOVER'
backend_application_name0 = 'server1'

backend_hostname1 = 'server2'
backend_port1 = 5432
backend_weight1 = 1
backend_data_directory1 = '/data/pg_data'
backend_flag1 = 'ALLOW_TO_FAILOVER'
backend_application_name1 = 'server2'

backend_hostname2 = 'server3'
backend_port2 = 5432
backend_weight2 = 1
backend_data_directory2 = '/data/pg_data'
backend_flag2 = 'ALLOW_TO_FAILOVER'
backend_application_name2 = 'server3'

## - Authentication -
enable_pool_hba = on
pool_passwd = 'pool_passwd'
# [LOGS]
logging_collector = on
log_directory = '/data/pgpool_log'
log_filename = 'pgpool-%d.log'
log_file_mode = 0600
log_truncate_on_rotation = on
log_rotation_age = 1d
log_rotation_size = 100MB
# [FILE LOCATIONS]
pid_file_name = '/runpg/pgpool/pgpool.pid'
## 此目录用来存放 pgpool_status 文件，此文件保存集群状态（刷新有问题时会造成show pool_status不正确）
logdir = '/tmp'
# [Streaming REPLICATION MODE]
sr_check_user = 'pgpool'
sr_check_password = '123qwert'
follow_primary_command = '/usr/local/pgpool/etc/follow_primary.sh %d %h %p %D %m %H %M %P %r %R'

# [HEALTH CHECK GLOBAL PARAMETERS]
health_check_period = 5
health_check_timeout = 20
health_check_user = 'pgpool'
## 为健康检查时查找 pool_passwd
health_check_password = '123qwert'
health_check_max_retries = 3
# [FAILOVER AND FAILBACK]
failover_command = '/usr/local/pgpool/etc/failover.sh %d %h %p %D %m %H %M %P %r %R %N %S'
# [ONLINE RECOVERY]
recovery_user = 'postgres'
recovery_password = '123qwert'
recovery_1st_stage_command = 'recovery_1st_stage'
# [WATCHDOG]
use_watchdog = on
hostname0 = 'server1'
wd_port0 = 9000
pgpool_port0 = 9999

hostname1 = 'server2'
wd_port1 = 9000
pgpool_port1 = 9999

hostname2 = 'server3'
wd_port2 = 9000
pgpool_port2 = 9999

wd_ipc_socket_dir = '/runpg/postgresql'

## - Virtual IP control Setting -
delegate_IP = '192.168.254.99'
## - Behaivor on escalation Setting -
wd_escalation_command=''
或者
wd_escalation_command = '/usr/local/pgpool/etc/escalation.sh'

## - Lifecheck Setting -
wd_lifecheck_method = 'heartbeat'
### -- heartbeat mode --
heartbeat_hostname0 = 'server1'
heartbeat_port0 = 9694
heartbeat_device0 = ''

heartbeat_hostname1 = 'server2'
heartbeat_port1 = 9694
heartbeat_device1 = ''

heartbeat_hostname2 = 'server3'
heartbeat_port2 = 9694
heartbeat_device2 = ''

在100/101/102上面安装PG：

[root@localhost src]# tar -zxf postgresql-13.4.tar.gz
[root@localhost src]# cd postgresql-13.4/
[root@localhost src]# ./configure  --prefix=/usr/local/pgsql
[root@localhost src]# make world	&& make install-world
[root@localhost src]# groupadd postgres && useradd -g postgres postgres
[root@localhost src]# passwd postgres
[root@localhost src]# mkdir -p /data/pg_data &&  mkdir -p /data/pg_archive && mkdir -p /data/pg_log&& mkdir -p /data/pgpool_logs
[root@localhost src]# chown -R postgres:postgres /data

在100/101/102上环境设置：
/root/.bash_profile和/home/postgres/.bash_profile配置

# .bash_profile
# Get the aliases and functions
if [ -f ~/.bashrc ]; then
	. ~/.bashrc
fi
# User specific environment and startup programs

PATH=$PATH:$HOME/.local/bin:$HOME/bin

export PATH
export PGPORT=5432
export PGDATA=/data/pg_data
export PGHOME=/usr/local/pgsql
export LD_LIBRARY_PATH=$PGHOME/lib:/lib64:/usr/lib64:/usr/local/lib64:/lib:/usr/lib:/usr/local/lib:$LD_LIBRARY_PATH
export PATH=$PGHOME/bin:$PATH:.
export MANPATH=$PGHOME/share/man:$MANPATH
export PGUSER=postgres
export PGDATABASE=postgres

alias rm='rm -i'
alias ll='ls -lh'
export LANG="zh_CN.UTF8"

安装pgpool-recovery

[root@allserver etc]# cd /usr/local/src/pgpool-II-4.2.4/src/sql/pgpool-recovery/
[root@allserver pgpool-recovery]# make && make install

在100上初始化数据库：

[postgres@server1 ~]$ initdb -D /data/pg_data -E UTF-8 --locale=C -U postgres -W

100数据库配置文件postgresql.conf:

listen_addresses = '*'
archive_mode = on
archive_command = 'test ! -f /data/pg_archive/%f && cp %p /data/pg_archive/%f '
max_wal_senders = 10
max_replication_slots = 10
wal_level = replica
hot_standby = on
wal_log_hints = on

进入数据库：

postgres=# CREATE user pgpool  password '123qwert';
postgres=# CREATE user replic  password '123qwert';
postgres=# GRANT pg_monitor TO pgpool;
postgres=# \c template1 
template1=# CREATE EXTENSION pgpool_recovery;

配置认证文件pg_hba.conf 添加：

host    all             all             192.168.254.1/24     **粗体**     md5
host    replication     all             192.168.254.1/24           md5

在101/102上面建立基础备份并启动：

[postgres@server2/3 ~]$ pg_basebackup  -h 192.168.254.100 -Ureplic -R -P --verbose -c fast -D /data/pg_data/ -F p  -C --slot='slot101' 
(在102上就是--slot='slot102')
[postgres@server2/3 ~]$ pg_ctl -D /data/pg_data/ start

在100上查看主从复制信息：

postgres=# select pid,usesysid,usename,client_addr,backend_start,state,flush_lsn,replay_lsn,write_lsn,write_lag,flush_lag,sync_state from pg_stat_replication ;

image.png

在100/101/102上设置host：

echo "192.168.254.100 server1" >> /etc/hosts
echo "192.168.254.101 server2" >> /etc/hosts
echo "192.168.254.102 server3" >> /etc/hosts

分别修改 hostname

[server1]# hostnamectl set-hostname server1
[server2]# hostnamectl set-hostname server2
[server3]# hostnamectl set-hostname server3

查看是否修改成功：

[root@localhost postgresql-13.4]# uname -a
Linux server1 3.10.0-957.el7.x86_64 #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

配置ssh互信（分别在root和postgres用户下面进行配置）：

[root@allserver ~]#  mkdir ~/.ssh;  cd ~/.ssh
[root@allserver .ssh]# ssh-keygen -t rsa -f id_rsa_pgpool
[root@allserver .ssh]# ssh-copy-id -i id_rsa_pgpool.pub postgres@server1
[root@allserver .ssh]# ssh-copy-id -i id_rsa_pgpool.pub postgres@server2
[root@allserver .ssh]# ssh-copy-id -i id_rsa_pgpool.pub postgres@server3

[root@allserver .ssh]# su - postgres
[postgres@allserver ~]$ cd ~/.ssh/
[postgres@allserver .ssh]$ ssh-keygen -t rsa -f id_rsa_pgpool
[postgres@allserver .ssh]$  ssh-copy-id -i id_rsa_pgpool.pub postgres@server1
[postgres@allserver .ssh]$  ssh-copy-id -i id_rsa_pgpool.pub postgres@server2
[postgres@allserver .ssh]$  ssh-copy-id -i id_rsa_pgpool.pub postgres@server3

测试看是否免密登录：

ssh postgres@serverNo -i ~/.ssh/id_rsa_pgpool

在100/101/102上面的PG安装目录下面创建.pgpass文件：

[postgres@allserver ~]$ su - postgres
[postgres@allserver ~]$ vim ~/.pgpass
server1:5432:replication:replic:123qwert
server2:5432:replication:replic:123qwert
server3:5432:replication:replic:123qwert
server1:5432:postgres:postgres:123qwert
server2:5432:postgres:postgres:123qwert
server3:5432:postgres:postgres:123qwert
[postgres@allserver ~]$ chmod 0600 ~/.pgpass

从 Pgpool-II 4.2 中，现在所有主机的所有配置参数都相同。如果启用了监视器功能，以消除对哪个主机是哪个主机的干扰，则需要pgpool_node_id文件。需要创建一个pgpool_node_id文件，并指定pgpool（看门狗）节点编号（例如0，1，2…）来识别pgpool（看门狗）主机。

[root@server1 etc]# echo "0" >> /usr/local/pgpool/etc/pgpool_node_id
[root@server2 etc]# echo "1" >> /usr/local/pgpool/etc/pgpool_node_id
[root@server3 etc]# echo "2" >> /usr/local/pgpool/etc/pgpool_node_id

为follow_primary.sh中的PCP_USER=pgpool配置免密登录

[root@allserver etc]# 
echo 'pgpool:'`pg_md5 123qwert` >>/usr/local/pgpool/etc/pcp.conf
  echo 'postgres:'`pg_md5 123qwert` >>/usr/local/pgpool/etc/pcp.conf
[root@allserver etc]# su - postgres
[postgres@allserver ~]$ 
echo 'localhost:9898:pgpool:123qwert' >> ~/.pcppass;
echo '192.168.254.99:9898:pgpool:123qwert' >> ~/.pcppass;
echo 'server1:9898:pgpool:123qwert' >> ~/.pcppass; 
echo 'server2:9898:pgpool:123qwert' >> ~/.pcppass;
echo 'server3:9898:pgpool:123qwert' >> ~/.pcppass;
[postgres@allserver ~]$ chmod 600 ~/.pcppass

#启动pgpool(先后分别在server 1、2、3上启动)

[postgres@allserver ~]$ pgpool -D -d -n &

主从模式
可以用两种方式进行实现
1，手动使用pg_basebackup来操作
2，可以使用pcp_recovery_node来进行添加
2.1，

[server1]# pcp_recovery_node -h 192.168.254.99 -p 9898 -U pgpool -n 1

2.2，

[server1]# pcp_recovery_node -h 192.168.254.99 -p 9898 -U pgpool -n 2

image.png
添加成功之后，会自动的启动从库，无需再手动启动

集群管理

pgpool 集群
查看集群配置信息

pcp_pool_status -h 192.168.254.99 -p 9898 -U pgpool -v

查看集群节点详情
#-h 表示集群IP，-p 表示PCP管道端口（默认是9898），-U 表示 PCP管道用户，-v表示查看详细内容

pcp_watchdog_info -h  192.168.254.99 -p 9898 -U pgpool -v -w

查看节点数量

pcp_node_count -h 192.168.254.99 -p 9898 -U pgpool -w

查看指定节点信息

pcp_node_info -h 192.168.254.99 -p 9898 -U pgpool -n 0 -v -w

增加一个集群节点
#-n 表示节点序号（从0开始）

pcp_attach_node -h 192.168.254.99 -p 9898 -U pgpool -n 0 -v -w

脱离一个集群节点

pcp_detach_node -h 192.168.254.99 -p 9898 -U pgpool -n 0 -v -w

提升一个备用节点为活动节点

pcp_promote_node -h 192.168.254.99 -p 9898 -U pgpool -n 0 -v -w

恢复一个离线节点为集群节点

pcp_recovery_node -h 192.168.254.99 -p 9898 -U pgpool -n 0 -v -w

PostgresSQL集群
连接集群

[all servers]$ psql -h 192.168.254.99 -p 9999

查看集群状态

[all servers]$ psql -h 192.168.254.99 -p 9999 -U postgres postgres -c "show pool_nodes"

image.png

show pool_status;查看相关参数配置
image.png

五，PGpool-II高可用测试

高可用测试：
目前状态：
image.png
Vip位于100上。

1，停掉100上面的pg数据库
image.png
结果：主库原来的server2上面的从库被提升为主库，原来的sever1的主库将为从库，server3的从库被重新指向新的主库

2， 再次切换：
停掉101上面的主库。
image.png
结果：主库原来的server1上面的从库被提升为主库，原来的sever2的主库将为从库，server3的从库被重新指向新的主库

3，关闭100虚拟机
image.png
image.png
结果：原来的server2的从库被提升为新主库，server3的从库重新指向server2，原来在sever1上的vip漂移到server3 102上。

4，恢复100
image.png
image.png
结果：server1启动之后，sever1依然是“down”状态，需要进行手动加入到集群中。

手动恢复节点1
image.png

测试完毕

pgpool-ii高可用postgresql高可用pg高可用pgpool部署pg安装部署
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