postgresql集羣的搭建

目錄

  • 架構圖
  • 部署詳情
  • postgresql的安裝與配置
  • pgpool的安裝與配置

寫在安裝前

postgresql是一款很強大的數據庫,具體有多強大呢,請谷歌。。。
網上的相關資料不是不少,參考了大神們的文檔,結合本身趟了的坑,寫了pg集羣的安裝文檔。可能有一些參數沒有配置好,但願大神們指出,謝謝。參照本文檔,基本能實現pg的高可用,稍後會寫出測試文檔。javascript

架構圖

 
 

部署詳情

ip host 系統 vip 部署
192.168.123.180 master CentOS 6.8 192.168.123.183 postgresql、pgpool
192.168.123.181 slave1 CentOS 6.8 192.168.123.183 postgresql、pgpool
192.168.123.182 slave2 CentOS 6.8 192.168.123.183 postgresql

postgresql的安裝

一、安裝

一、Rpm包下載地址:
https://yum.postgresql.org/rpmchart.php
下載下面的包:
postgresql95-libs-9.5.8-1PGDG.rhel6.x86_64.rpm
postgresql95-contrib-9.5.8-1PGDG.rhel6.x86_64.rpm
postgresql95-9.5.8-1PGDG.rhel6.x86_64.rpm
postgresql95-server-9.5.8-1PGDG.rhel6.x86_64.rpmphp

二、安裝:css

yum install -y postgresql95-libs-9.5.8-1PGDG.rhel6.x86_64.rpm yum install -y postgresql95-contrib-9.5.8-1PGDG.rhel6.x86_64.rpm yum install -y postgresql95-9.5.8-1PGDG.rhel6.x86_64.rpm yum install -y postgresql95-server-9.5.8-1PGDG.rhel6.x86_64.rpm 

三、初始化db:
service postgresql-9.5 initdb
四、設置爲開機啓動:
chkconfig postgresql-9.5 on
五、安裝的目錄:
/var/lib/pgsql/9.5前端

配置白名單與流複製

一、 master的配置java

PostgreSQL流複製默認是異步的。在主服務器上提交事務和從服務器上變化可見之間有一個小的延遲,這個延遲遠小於基於文件日誌傳送,一般1秒能完成。若是主服務器忽然崩潰,可能會有少許數據丟失。
同步複製必須等主服務器和從服務器都寫完WAL後才能提交事務。這樣在必定程度上會增長事務的響應時間。
配置同步複製僅須要一個額外的配置步驟: synchronous_standby_names必須設置爲一個非空值。synchronous_commit也必須設置爲on。
這裏部署的是異步的流複製node

1.二、配置白名單:
vim /var/lib/pgsql/9.5/data/pg_hba.conf
在配置文件最後加上:sql

host   all             all              192.168.123.180/32      trust
host   all             all              192.168.123.181/32      trust
host   all             all              192.168.123.182/32      trust
host   replication      replica          192.168.123.181/32      trust
host   replication      replica          192.168.123.182/32      trust

保存退出
我這裏因爲是內網,所有用的trust,若是要用密碼,請修改成passwd數據庫

1.三、修改配置文件:
vim /var/lib/pgsql/9.5/data/postgresql.confvim

data_directory = '/app/pgsql/data' #自定義data目錄 listen_addresses = '*' #監聽全部ip archive_mode = on #容許歸檔 archive_command = 'cp %p /app/pgsql/pg_archive/%f' #使用命令歸檔 wal_level = hot_standby #選擇熱備 max_wal_senders = 16 #最多多少個流複製連接 wal_keep_segments = 256 #流複製保留最多的xlog數 wal_sender_timeout = 60s #流複製主機發送數據超時時間 max_connections = 99 #從庫的max_connections必須大於主庫的 

1.四、建立data目錄,賦權並修改啓動文件後端

mkdir -p /app/pgsql/data && chown postgres:postgres /app/pgsql/data
mkdir -p /app/pgsql/pg_archive && chown postgres:postgres /app/pgsql/pg_archive

cd /app/pgsql && chmod 700 data cd /app/pgsql && chmod 700 pg_archive 

1.五、修改啓動文件

vim /etc/init.d/postgresql-9.5 PGDATA=/app/pgsql/data 

1.六、把原data目錄下的文件copy到新的data的目錄下,並改變屬組:

cp -r /var/lib/pgsql/9.5/data/* /app/pgsql/data/ cd /app/pgsql && chown -R postgres:postgres data 

1.七、啓動
service postgresql-9.5 start
之後修改配置文件就在/app/pgsql/data下面修改

1.八、建立一個數據庫用戶進行主從同步。建立用戶replica,並賦予登陸和複製的權限
登錄到數據庫裏:

su postgres
psql
CREATE ROLE replica login replication encrypted password 'replica'; 
 
 

防火牆開放5432端口
在從庫上:
psql -h 192.168.123.180 -U postgres

 
 

 

登錄主庫成功

二、從庫的配置
2.一、自定義data目錄:

mkdir -p /app/pgsql/data/&&chmod 700 /app/pgsql/data/
chown -R  postgres:postgres pgsql

mkdir /app/pgsql/pg_archive
cd /app/pgsql chmod 700 pg_archive && chown postgres:postgres pg_archive/ 

2.二、切換用戶:
su – postgres
2.三、備份數據:
pg_basebackup -h 192.168.123.180 -U replica -D /app/pgsql/data -X stream –P
2.四、修改啓動文件:

vim /etc/init.d/postgresql-9.5 PGDATA=/app/pgsql/data 

2.五、配置recovery.conf

su postgres
cp /usr/pgsql-9.5/share/recovery.conf.sample /app/pgsql/data/recovery.conf

vim /app/pgsql/data/recovery.conf

standby_mode = on        \#該節點爲從 primary_conninfo = 'host=192.168.123.180 port=5432 user=replica password=replica' \#主服務器的ip、user recovery_target_timeline = 'latest' trigger_file = '/tmp/trigger_file0' 

2.六、配置postgresql.conf
vim /app/pgsql/data/postgresql.conf

max_connections = 999     #大於主的鏈接數 max_standby_streaming_delay = 30s wal_receiver_status_interval = 10s hot_standby_feedback = on 

2.七、重啓服務:
service postgresql-9.5 restart

驗證流複製

3.一、在master上登錄psql
查看狀態:
select client_addr,sync_state from pg_stat_replication;

 
 

 

3.二、建立test庫
Create database test;

3.三、slave上登錄psql
查看庫
playboy => \l

 
 

 

發現已同步。

pgpool的安裝

pgpool-II是PostgreSQL服務器之間一種有效的中間件和PostgreSQL數據庫客戶端。它提供瞭如下功能。
鏈接池
pgpool-II保存到PostgreSQL服務器的鏈接,當一個相同新鏈接(如用戶名、數據庫、協議版本)進來時,重用他們。它減小了鏈接開銷,提升了系統的總體吞吐量。
複製
pgpool-II能夠管理多個PostgreSQL服務器。使用複製功能可使2個或更多的物理磁盤上建立一個實時備份,這樣服務不會因服務器的磁盤故障而中斷。
負載平衡
若是數據庫是複製的,在任何服務器上執行一個SELECT查詢會返回相同的結果。pgpool-II複製特性的優點在於減小每一個PostgreSQL服務器上的負載,由於它可使用分佈在多個服務器之間進行SELECT查詢,從而提升系統的總體吞吐量。最好是查詢和PostgreSQL服務器數量成必定比例,多用戶同時執行多查詢達到負載均衡最好的效果。
限制鏈接數
PostgreSQL的最大併發鏈接數有必定限制的,當超過限制的鏈接數後,鏈接會被拒絕。然而,設置增長最大鏈接數又會增長資源消耗,影響系統性能。pgpool-II也有最大鏈接數限制,但超過的鏈接進來時是進行當即排隊,而不是返回一個錯誤。
pgpool-II交互PostgreSQL的後端和前端協議時,起着繼電器的做用。所以,數據庫應用程序(前端)認爲pgpool-II是真實的PostgreSQL服務器,服務器(後端)認爲pgpool-II是它的客戶端之一。由於pgpool-II在服務器和客戶端是透明的,因此pgpool-II可使用現有的數據庫應用程序而作到幾乎不修改它們。

版本:3.6
機器:192.168.123.180
192.168.123.181
4.一、免密碼登錄
安裝以前先配置密鑰使master和slave1這兩臺虛擬機的postgres用戶能免密鏈接

先修改postgres的密碼,在root用戶下
passwd postgres
新密碼123456

Master到slave1的免密碼登錄:
在master上切換至postgres用戶,生成密鑰
su postgres ssh-keygen -t rsa
而後全輸入回車

切換到postgres用戶:
su postgres ssh-copy-id -i /var/lib/pgsql/.ssh/id_rsa 192.168.123.181
而後ssh 192.168.123.181 成功,實現master到slave1的免密碼登錄

Slave1到master的免密碼登錄:
流程同上
4.二、安裝
Rpm包下載地址:
http://www.pgpool.net/yum/rpms/3.6/redhat/rhel-6-x86_64/pgpool-II-pg95-3.6.0-1pgdg.rhel6.x86_64.rpm

安裝:
yum install pgpool-II-pg95-3.6.0-1pgdg.rhel6.x86_64.rpm

4.三、配置
Master的配置:

配置白名單:
要和pg_hba.conf登錄權限一致,這裏因爲是私有云,都用trust
vim /etc/pgpool-II/pool_hba.conf
在最後改爲:


 
 

配置pcp管理工具密碼:
pg_md5 pwd
密碼加密


 
 

vim /etc/pgpool-II/pcp.conf
把剛纔加密的密碼粘貼到文件裏

 
 

配置系統命令權限:
Root用戶下:
chmod u+s /sbin/ifconfig &&chmod u+s /usr/sbin

配置中間件配置文件:
vim /etc/pgpool-II/pgpool.conf

# CONNECTIONS listen_addresses = '*' port = 9999 pcp_listen_addresses = '*' pcp_port = 9898 # - Backend Connection Settings - backend_hostname0 = 'master' backend_port0 = 5432 backend_weight0 = 1 backend_data_directory0 = ' /app/pgsql/data' backend_flag0 = 'ALLOW_TO_FAILOVER' backend_hostname1 = 'slave' backend_port1 = 5432 backend_weight1 = 1 backend_data_directory1 = ' /app/pgsql/data'' backend_flag1 = 'ALLOW_TO_FAILOVER' # - Authentication - enable_pool_hba = off pool_passwd = 'pool_passwd' # FILE LOCATIONS pid_file_name = '/opt/pgpool/pgpool.pid' replication_mode = off load_balance_mode = on master_slave_mode = on master_slave_sub_mode = 'stream' sr_check_period = 5 sr_check_user = 'repuser' sr_check_password = 'repuser' sr_check_database = 'postgres' #------------------------------------------------------------------------------ # HEALTH CHECK 健康檢查 #------------------------------------------------------------------------------ health_check_period = 10 # Health check period # Disabled (0) by default health_check_timeout = 20 # Health check timeout # 0 means no timeout health_check_user = ' repuser ' # Health check user health_check_password = ' repuser ' #數據庫密碼 # Password for health check user health_check_database = 'postgres' #必須設置,不然primary數據庫down了,pgpool不知道,不能及時切換。從庫流複製還在鏈接數據,報鏈接失敗。 #只有下次使用pgpool登陸時,發現鏈接不上,而後報錯,這時候,才知道掛了,pgpool進行切換。 #主備切換的命令行配置 #------------------------------------------------------------------------------ # FAILOVER AND FAILBACK #------------------------------------------------------------------------------ failover_command = ' /opt/pgpool/failover_stream.sh %d %H /tmp/trigger_file0 ' #------------------------------------------------------------------------------ # WATCHDOG #------------------------------------------------------------------------------ # - Enabling - use_watchdog = on # - Watchdog communication Settings - wd_hostname = 'master' # Host name or IP address of this watchdog # (change requires restart) wd_port = 9000 # port number for watchdog service # (change requires restart) # - Virtual IP control Setting - delegate_IP = ' 192.168.123.183 ' # delegate IP address # If this is empty, virtual IP never bring up. # (change requires restart) if_cmd_path = '/sbin' # path to the directory where if_up/down_cmd # (change requires restart) if_up_cmd = 'ifconfig eth0:0 inet $_IP_$ netmask 255.255.255.0' # startup delegate IP command # (change requires restart) if_down_cmd = 'ifconfig eth0:0 down' # shutdown delegate IP command # (change requires restart) # -- heartbeat mode -- wd_heartbeat_port = 9694 # Port number for receiving heartbeat signal # (change requires restart) wd_heartbeat_keepalive = 2 # Interval time of sending heartbeat signal (sec) # (change requires restart) wd_heartbeat_deadtime = 30 # Deadtime interval for heartbeat signal (sec) # (change requires restart) heartbeat_destination0 = 'slave1' # Host name or IP address of destination 0 # for sending heartbeat signal. # (change requires restart) heartbeat_destination_port0 = 9694 # Port number of destination 0 for sending # heartbeat signal. Usually this is the # same as wd_heartbeat_port. # (change requires restart) heartbeat_device0 = 'eth0' # Name of NIC device (such like 'eth0') # used for sending/receiving heartbeat # signal to/from destination 0. # This works only when this is not empty # and pgpool has root privilege. # (change requires restart) # - Other pgpool Connection Settings - other_pgpool_hostname0 = 'slave' #對端 # Host name or IP address to connect to for # (change requires restart) other_pgpool_port0 = 9999 # Port number for othet pgpool 0 # (change requires restart) other_wd_port0 = 9000 # Port number for othet watchdog 0 # (change requires restart) 

4.四、Slave1的配置:

配置白名單:
要和pg_hba.conf登錄權限一致,這裏因爲是私有云,都用trust
vim /etc/pgpool-II/pool_hba.conf
在最後改爲:

配置pcp管理工具密碼:
pg_md5 pwd
密碼加密

vim /etc/pgpool-II/pcp.conf
把剛纔加密的密碼粘貼到文件裏

配置系統命令權限:
Root用戶下:
chmod u+s /sbin/ifconfig &&chmod u+s /usr/sbin

配置中間件配置文件:
vim /etc/pgpool-II/pgpool.conf

# CONNECTIONS listen_addresses = '*' port = 9999 pcp_listen_addresses = '*' pcp_port = 9898 # - Backend Connection Settings - backend_hostname0 = 'master' backend_port0 = 5432 backend_weight0 = 1 backend_data_directory0 = ' /app/pgsql/data' backend_flag0 = 'ALLOW_TO_FAILOVER' backend_hostname1 = 'slave1' backend_port1 = 5432 backend_weight1 = 1 backend_data_directory1 = '/app/pgsql/data ' backend_flag1 = 'ALLOW_TO_FAILOVER' # - Authentication - enable_pool_hba = off pool_passwd = 'pool_passwd' # FILE LOCATIONS pid_file_name = '/opt/pgpool/pgpool.pid' replication_mode = off load_balance_mode = on master_slave_mode = on master_slave_sub_mode = 'stream' sr_check_period = 5 sr_check_user = 'repuser' sr_check_password = 'repuser' sr_check_database = 'postgres' #------------------------------------------------------------------------------ # HEALTH CHECK 健康檢查 #------------------------------------------------------------------------------ health_check_period = 10 # Health check period # Disabled (0) by default health_check_timeout = 20 # Health check timeout # 0 means no timeout health_check_user = ' repuser ' # Health check user health_check_password = ' repuser ' #數據庫密碼 # Password for health check user health_check_database = 'postgres' #必須設置,不然primary數據庫down了,pgpool不知道,不能及時切換。從庫流複製還在鏈接數據,報鏈接失敗。 #只有下次使用pgpool登陸時,發現鏈接不上,而後報錯,這時候,才知道掛了,pgpool進行切換。 #主備切換的命令行配置 #------------------------------------------------------------------------------ # FAILOVER AND FAILBACK #------------------------------------------------------------------------------ failover_command = '/opt/pgpool/failover_stream.sh %d %H /tmp/trigger_file0 ' #------------------------------------------------------------------------------ # WATCHDOG #------------------------------------------------------------------------------ # - Enabling - use_watchdog = on # - Watchdog communication Settings - wd_hostname = 'slave1' #本端 # Host name or IP address of this watchdog # (change requires restart) wd_port = 9000 # port number for watchdog service # (change requires restart) # - Virtual IP control Setting - delegate_IP = '192.168.123.183' # delegate IP address # If this is empty, virtual IP never bring up. # (change requires restart) if_cmd_path = '/sbin' # path to the directory where if_up/down_cmd exists # (change requires restart) if_up_cmd = 'ifconfig eth0:0 inet $_IP_$ netmask 255.255.255.0' # startup delegate IP command # (change requires restart) if_down_cmd = 'ifconfig eth0:0 down' # shutdown delegate IP command # (change requires restart) # -- heartbeat mode -- wd_heartbeat_port = 9694 # Port number for receiving heartbeat signal # (change requires restart) wd_heartbeat_keepalive = 2 # Interval time of sending heartbeat signal (sec) # (change requires restart) wd_heartbeat_deadtime = 30 # Deadtime interval for heartbeat signal (sec) # (change requires restart) heartbeat_destination0 = 'master' #對端 # Host name or IP address of destination 0 # for sending heartbeat signal. # (change requires restart) heartbeat_destination_port0 = 9694 # Port number of destination 0 for sending # heartbeat signal. Usually this is the # same as wd_heartbeat_port. # (change requires restart) heartbeat_device0 = 'eth0' # Name of NIC device (such like 'eth0') # used for sending/receiving heartbeat # signal to/from destination 0. # This works only when this is not empty # and pgpool has root privilege. # (change requires restart) # - Other pgpool Connection Settings - other_pgpool_hostname0 = 'master' #對端 # Host name or IP address to connect to for # (change requires restart) other_pgpool_port0 = 9999 # Port number for othet pgpool 0 # (change requires restart) other_wd_port0 = 9000 # Port number for othet watchdog 0 # (change requires restart) 

下面在master和slave1這兩臺機器上
mkdir /opt/pgpool &&chown postgres:postgres /opt/pgpool

master上:

cd /opt/pgpool vim failover_stream.sh 
# Failover command for streaming replication. # This script assumes that DB node 0 is primary, and 1 is standby. # # If standby goes down, do nothing. If primary goes down, create a # trigger file so that standby takes over primary node. # # Arguments: $1: failed node id. $2: new master hostname. $3: path to # trigger file. failed_node=192.168.123.180 new_master=192.168.123.181 trigger_file=$3 # Do nothing if standby goes down. if [ $failed_node = 1 ]; then exit 0; fi # Create the trigger file. /usr/bin/ssh -T $new_master /bin/touch $trigger_file exit 0; 

保存退出,並賦權
chown postgres:postgres failover_stream.sh &&chmod 777 failover_stream.sh

slave1上:

cd /opt/pgpool vim failover_stream.sh 
#! /bin/sh # Failover command for streaming replication. # This script assumes that DB node 0 is primary, and 1 is standby. # # If standby goes down, do nothing. If primary goes down, create a # trigger file so that standby takes over primary node. # # Arguments: $1: failed node id. $2: new master hostname. $3: path to # trigger file. failed_node=192.168.123.181 new_master=192.168.123.180 trigger_file=$3 # Do nothing if standby goes down. if [ $failed_node = 1 ]; then exit 0; fi # Create the trigger file. /usr/bin/ssh -T $new_master /bin/touch $trigger_file exit 0; 

保存退出並賦權:
chown postgres:postgres failover_stream.sh &&chmod 777 failover_stream.sh

在master和salve1上建立日誌文件:

mkdir /var/log/pgpool chown -R postgres.postgres /var/log/pgpool mkdir /var/run/pgpool chown -R postgres.postgres /var/run/pgpool 

配置host:
在master、slave一、slave2的/etc/hosts配置ip映射

192.168.123.180 master 192.168.123.181 slave1 192.168.123.182 slave2 

在master上建立repusr帳號:

su postgres
psql
create user repuser with password 'repuser'; 

防火牆開放:5432 9999 9898 9000 9694
4.五、啓動pgpool
先在master上啓動pgpool:
pgpool -n -d -D > /var/log/pgpool/pgpool.log 2>&1 &

再在slave1上啓動pgpool:
pgpool -n -d -D > /var/log/pgpool/pgpool.log 2>&1 &
Master上的ifconfig會多一個虛擬ip出來

快速中止pgpool的指令:
pgpool -m fast stop
鏈接虛擬ip進入數據庫:

Su postgres psql -h 192.168.123.183 -p 9999 

查看集羣節點狀態:
show pool_nodes;

寫在安裝後

寫文檔才發現,邊安裝邊趟坑邊記錄,還要注意格式是多麼愉(xin)快(ku)的事,本着開源精神,貼出來給要用到pg集羣的小夥伴們參考,本文侵刪

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