咱們一般說的雙機熱備是指兩臺機器都在運行,但並非兩臺機器都同時在提供服務。當提供服務的一臺出現故障的時候,另一臺會立刻自動接管而且提供服務,並且切換的時間很是短。MySQL雙主複製,即互爲Master-Slave(只有一個Master提供寫操做),能夠實現數據庫服務器的熱備,可是一個Master宕機後不能實現動態切換。使用Keepalived,能夠經過虛擬IP,實現雙主對外的統一接口以及自動檢查、失敗切換機制,從而實現MySQL數據庫的高可用方案。以前梳理了Mysql主從/主主同步,下面說下Mysql+keeoalived雙主熱備高可用方案的實施。html
Keepalived看名字就知道,保持存活,在網絡裏面就是保持在線了,也就是所謂的高可用或熱備,用來防止單點故障(單點故障是指一旦某一點出現故障就會導 整個系統架構的不可用)的發生,那說到keepalived不得不說的一個協議不是VRRP協議,能夠說這個協議就是keepalived實現的基礎。 1)Keepalived的工做原理是VRRP(Virtual Router Redundancy Protocol)虛擬路由冗餘協議。在VRRP中有兩組重要的概念:VRRP路由器和虛擬路由器,主控路由器和備份路由器。 2)VRRP路由器是指運行VRRP的路由器,是物理實體,虛擬路由器是指VRRP協議建立的,是邏輯概念。一組VRRP路由器協同工做,共同構成一臺虛擬路由器。 Vrrp中存在着一種選舉機制,用以選出提供服務的路由即主控路由,其餘的則成了備份路由。當主控路由失效後,備份路由中會從新選舉出一個主控路由,來繼 續工做,來保障不間斷服務。
過多內容在這裏就不作詳細介紹了,下面詳細記錄下Mysql+Keepalived雙主熱備的高可用方案的操做記錄mysql
1)先實施Master->Slave的主主同步。主主是數據雙向同步,主從是數據單向同步。通常狀況下,主庫宕機後,須要手動將鏈接切換到從庫上。(可是用keepalived就能夠自動切換) 2)再結合Keepalived的使用,經過VIP實現Mysql雙主對外鏈接的統一接口。即客戶端經過Vip鏈接數據庫;當其中一臺宕機後,VIP會漂移到另外一臺上,這個過程對於客戶端的數據鏈接來講幾乎無感受,從而實現高可用。
環境描述: mysql的安裝能夠參考:http://www.cnblogs.com/kevingrace/p/6109679.html Centos6.8版本 Master1:182.148.15.238 安裝mysql和keepalived Master2: 182.148.15.237 安裝mysql和keepalived VIP:182.148.15.236 要實現主主同步,能夠先實現主從同步,即master1->master2的主從同步,而後master2->master1的主從同步. 這樣,雙方就完成了主主同步。 注意下面幾點: 1)要保證同步服務期間之間的網絡聯通。即能相互ping通,能使用對方受權信息鏈接到對方數據庫(防火牆開放3306端口)。 2)關閉selinux。 3)同步前,雙方數據庫中須要同步的數據要保持一致。這樣,同步環境實現後,再次更新的數據就會如期同步了。
可能出現的問題linux
報錯: Last_IO_Error: Fatal error: The slave I/O thread stops because master and slave have equal MySQL server ids; these ids must be different for replication to work (or the --replicate-same-server-id option must be used on slave but this does not always make sense; please check the manual before using it). 解決辦法: 刪除mysql數據目錄下的auto.cnf文件,重啓mysql服務便可! 另:Keepalived必須使用root帳號啓動!!
1、Mysql主主同步環境部署sql
---------------master1服務器操做記錄--------------- 在my.cnf文件的[mysqld]配置區域添加下面內容: [root@master1 ~]# vim /usr/local/mysql/my.cnf server-id = 1 log-bin = mysql-bin sync_binlog = 1 binlog_checksum = none binlog_format = mixed auto-increment-increment = 2 auto-increment-offset = 1 slave-skip-errors = all [root@master1 ~]# /etc/init.d/mysql restart Shutting down MySQL. SUCCESS! Starting MySQL.. SUCCESS! 數據同步受權(iptables防火牆開啓3306端口)這樣I/O線程就能夠以這個用戶的身份鏈接到主服務器,而且讀取它的二進制日誌。 mysql> grant replication slave,replication client on *.* to wang@'182.148.15.%' identified by "wang@123"; Query OK, 0 rows affected (0.00 sec) mysql> flush privileges; Query OK, 0 rows affected (0.00 sec) 最好將庫鎖住,僅僅容許讀,以保證數據一致性;待主主同步環境部署後再解鎖; 鎖住後,就不能往表裏寫數據,可是重啓mysql服務後就會自動解鎖! mysql> flush tables with read lock; //注意該參數設置後,若是本身同步對方數據,同步前必定要記得先解鎖! Query OK, 0 rows affected (0.00 sec) 查看下log bin日誌和pos值位置 mysql> show master status; +------------------+----------+--------------+--------------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+--------------------------+-------------------+ | mysql-bin.000004 | 430 | | mysql,information_schema | | +------------------+----------+--------------+--------------------------+-------------------+ 1 row in set (0.00 sec) ---------------master2服務器操做記錄--------------- 在my.cnf文件的[mysqld]配置區域添加下面內容: [root@master2 ~]# vim /usr/local/mysql/my.cnf server-id = 2 log-bin = mysql-bin sync_binlog = 1 binlog_checksum = none binlog_format = mixed auto-increment-increment = 2 auto-increment-offset = 2 slave-skip-errors = all [root@master2 ~]# /etc/init.d/mysql restart Shutting down MySQL.. SUCCESS! Starting MySQL.. SUCCESS! mysql> grant replication slave,replication client on *.* to wang@'182.148.15.%' identified by "wang@123"; Query OK, 0 rows affected (0.00 sec) mysql> flush privileges; Query OK, 0 rows affected (0.00 sec) mysql> flush tables with read lock; Query OK, 0 rows affected (0.00 sec) mysql> show master status; +------------------+----------+--------------+--------------------------+-------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+--------------------------+-------------------+ | mysql-bin.000003 | 430 | | mysql,information_schema | | +------------------+----------+--------------+--------------------------+-------------------+ 1 row in set (0.00 sec) ---------------master1服務器作同步操做--------------- mysql> unlock tables; //先解鎖,將對方數據同步到本身的數據庫中 mysql> slave stop; mysql> change master to master_host='182.148.15.237',master_user='wang',master_password='wang@123',master_log_file='mysql-bin.000003',master_log_pos=430; Query OK, 0 rows affected, 2 warnings (0.01 sec) mysql> start slave; Query OK, 0 rows affected (0.01 sec) 查看同步狀態,以下出現兩個「Yes」,代表同步成功! mysql> show slave status \G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 182.148.15.237 Master_User: wang Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000003 Read_Master_Log_Pos: 430 Relay_Log_File: mysql-relay-bin.000002 Relay_Log_Pos: 279 Relay_Master_Log_File: mysql-bin.000003 Slave_IO_Running: Yes Slave_SQL_Running: Yes ......................... Seconds_Behind_Master: 0 ......................... 這樣,master1就和master2實現了主從同步,即master1同步master2的數據。 ---------------master2服務器作同步操做--------------- mysql> unlock tables; //先解鎖,將對方數據同步到本身的數據庫中 mysql> slave stop; mysql> change master to master_host='182.148.15.238',master_user='wang',master_password='wang@123',master_log_file='mysql-bin.000004',master_log_pos=430; Query OK, 0 rows affected, 2 warnings (0.06 sec) mysql> start slave; Query OK, 0 rows affected (0.01 sec) mysql> show slave status \G; *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 182.148.15.238 Master_User: wang Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000004 Read_Master_Log_Pos: 430 Relay_Log_File: mysql-relay-bin.000002 Relay_Log_Pos: 279 Relay_Master_Log_File: mysql-bin.000004 Slave_IO_Running: Yes Slave_SQL_Running: Yes ........................ Seconds_Behind_Master: 0 ........................ 這樣,master2就和master1實現了主從同步,即master2也同步master1的數據。 以上代表雙方已經實現了mysql主主同步。 當運行一段時間後,要是發現同步有問題,好比只能單向同步,雙向同步失效。能夠從新執行下上面的change master同步操做,只不過這樣同步後,只能同步在此以後的更新數據。下面開始進行數據驗證: -----------------主主同步效果驗證--------------------- 1)在master1數據庫上寫入新數據 mysql> unlock tables; Query OK, 0 rows affected (0.00 sec) mysql> create database huanqiu; Query OK, 1 row affected (0.01 sec) mysql> use huanqiu; Database changed mysql> create table if not exists haha ( -> id int(10) PRIMARY KEY AUTO_INCREMENT, -> name varchar(50) NOT NULL); Query OK, 0 rows affected (0.04 sec) mysql> insert into haha values(1,"王士博"); Query OK, 1 row affected (0.00 sec) mysql> insert into haha values(2,"郭慧慧"); Query OK, 1 row affected (0.00 sec) mysql> select * from haha; +----+-----------+ | id | name | +----+-----------+ | 1 | 王士博 | | 2 | 郭慧慧 | +----+-----------+ 2 rows in set (0.00 sec) 而後在master2數據庫上查看,發現數據已經同步過來了! mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | huanqiu | | mysql | | performance_schema | | test | +--------------------+ 5 rows in set (0.00 sec) mysql> use huanqiu; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed mysql> show tables; +-------------------+ | Tables_in_huanqiu | +-------------------+ | haha | +-------------------+ 1 row in set (0.00 sec) mysql> select * from haha; +----+-----------+ | id | name | +----+-----------+ | 1 | 王士博 | | 2 | 郭慧慧 | +----+-----------+ 2 rows in set (0.00 sec) 2)在master2數據庫上寫入新數據 mysql> create database hehe; Query OK, 1 row affected (0.00 sec) mysql> insert into huanqiu.haha values(3,"周正"),(4,"李敏"); Query OK, 2 rows affected (0.00 sec) Records: 2 Duplicates: 0 Warnings: 0 而後在master1數據庫上查看,發現數據也已經同步過來了! mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | hehe | | huanqiu | | mysql | | performance_schema | | test | +--------------------+ 6 rows in set (0.00 sec) mysql> select * from huanqiu.haha; +----+-----------+ | id | name | +----+-----------+ | 1 | 王士博 | | 2 | 郭慧慧 | | 3 | 周正 | | 4 | 李敏 | +----+-----------+ 4 rows in set (0.00 sec) 至此,Mysql主主同步環境已經實現。
2、配置Mysql+Keepalived故障轉移的高可用環境數據庫
1)安裝keepalived並將其配置成系統服務。master1和master2兩臺機器上一樣進行以下操做: [root@master1 ~]# yum install -y openssl-devel [root@master1 ~]# cd /usr/local/src/ [root@master1 src]# wget http://www.keepalived.org/software/keepalived-1.3.5.tar.gz [root@master1 src]# tar -zvxf keepalived-1.3.5.tar.gz [root@master1 src]# cd keepalived-1.3.5 [root@master1 keepalived-1.3.5]# ./configure --prefix=/usr/local/keepalived [root@master1 keepalived-1.3.5]# make && make install [root@master1 keepalived-1.3.5]# cp /usr/local/src/keepalived-1.3.5/keepalived/etc/init.d/keepalived /etc/rc.d/init.d/ [root@master1 keepalived-1.3.5]# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/ [root@master1 keepalived-1.3.5]# mkdir /etc/keepalived/ [root@master1 keepalived-1.3.5]# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/ [root@master1 keepalived-1.3.5]# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/ [root@master1 keepalived-1.3.5]# echo "/etc/init.d/keepalived start" >> /etc/rc.local 2)master1機器上的keepalived.conf配置。(下面配置中沒有使用lvs的負載均衡功能,因此不須要配置虛擬服務器virtual server) [root@master1 ~]# cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak [root@master1 ~]# vim /etc/keepalived/keepalived.conf #清空默認內容,直接採用下面配置: ! Configuration File for keepalived global_defs { notification_email { ops@wangshibo.cn tech@wangshibo.cn } notification_email_from ops@wangshibo.cn smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id MASTER-HA } vrrp_script chk_mysql_port { #檢測mysql服務是否在運行。有不少方式,好比進程,用腳本檢測等等 script "/opt/chk_mysql.sh" #這裏經過腳本監測 interval 2 #腳本執行間隔,每2s檢測一次 weight -5 #腳本結果致使的優先級變動,檢測失敗(腳本返回非0)則優先級 -5 fall 2 #檢測連續2次失敗纔算肯定是真失敗。會用weight減小優先級(1-255之間) rise 1 #檢測1次成功就算成功。但不修改優先級 } vrrp_instance VI_1 { state MASTER interface eth0 #指定虛擬ip的網卡接口 mcast_src_ip 182.148.15.238 virtual_router_id 51 #路由器標識,MASTER和BACKUP必須是一致的 priority 101 #定義優先級,數字越大,優先級越高,在同一個vrrp_instance下,MASTER的優先級必須大於BACKUP的優先級。這樣MASTER故障恢復後,就能夠將VIP資源再次搶回來 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 182.148.15.236 } track_script { chk_mysql_port } } 編寫切換腳本。KeepAlived作心跳檢測,若是Master的MySQL服務掛了(3306端口掛了),那麼它就會選擇自殺。Slave的KeepAlived經過心跳檢測發現這個狀況,就會將VIP的請求接管 [root@master1 ~]# vim /opt/chk_mysql.sh #!/bin/bash counter=$(netstat -na|grep "LISTEN"|grep "3306"|wc -l) if [ "${counter}" -eq 0 ]; then /etc/init.d/keepalived stop fi [root@master1 ~]# chmod 755 /opt/chk_mysql.sh 啓動keepalived服務 [root@master1 ~]# /etc/init.d/keepalived start 正在啓動 keepalived: [肯定] 4)master2機器上的keepalived配置。master2機器上的keepalived.conf文件只修改priority爲90、nopreempt不設置、real_server設置本地IP。 [root@master2 ~]# cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak [root@master2 ~]# >/etc/keepalived/keepalived.conf [root@master2 ~]# vim /etc/keepalived/keepalived.conf ! Configuration File for keepalived global_defs { notification_email { ops@wangshibo.cn tech@wangshibo.cn } notification_email_from ops@wangshibo.cn smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id MASTER-HA } vrrp_script chk_mysql_port { script "/opt/chk_mysql.sh" interval 2 weight -5 fall 2 rise 1 } vrrp_instance VI_1 { state BACKUP interface eth0 mcast_src_ip 182.148.15.237 virtual_router_id 51 priority 99 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 182.148.15.236 } track_script { chk_mysql_port } } [root@master2 ~]# cat /opt/chk_mysql.sh #!/bin/bash counter=$(netstat -na|grep "LISTEN"|grep "3306"|wc -l) if [ "${counter}" -eq 0 ]; then /etc/init.d/keepalived stop fi [root@master2 ~]# chmod 755 /opt/chk_mysql.sh [root@master2 ~]# /etc/init.d/keepalived start 正在啓動 keepalived: [肯定] 5)master1和master2兩臺服務器都要受權容許root用戶遠程登陸,用於在客戶端登錄測試! mysql> grant all on *.* to root@'%' identified by "1234567"; Query OK, 0 rows affected (0.00 sec) mysql> flush privileges; Query OK, 0 rows affected (0.01 sec) 6)在master1和master2兩臺機器上設置iptables防火牆規則,以下: [root@master1 ~]# cat /etc/sysconfig/iptables ........ -A INPUT -s 182.148.15.0/24 -d 224.0.0.18 -j ACCEPT #容許組播地址通訊 -A INPUT -s 182.148.15.0/24 -p vrrp -j ACCEPT #容許VRRP(虛擬路由器冗餘協)通訊 -A INPUT -m state --state NEW -m tcp -p tcp --dport 3306 -j ACCEPT #開放mysql的3306端口 [root@master1 ~]# /etc/init.d/iptables restart
3、Mysql+keepalived故障轉移的高可用測試vim
1)經過Mysql客戶端經過VIP鏈接,看是否鏈接成功。 好比,在遠程一臺測試機上鍊接,經過vip地址能夠正常鏈接(下面的鏈接權限要是在服務端提早受權的) [root@dev-new-test ~]# mysql -h182.148.15.236 -uroot -p123456 Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 60 Server version: 5.6.35-log Source distribution Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> select * from huanqiu.haha; +----+-----------+ | id | name | +----+-----------+ | 1 | 王士博 | | 2 | 郭慧慧 | | 3 | 周正 | | 4 | 李敏 | +----+-----------+ 4 rows in set (0.00 sec) 2)默認狀況下,vip是在master1上的。使用"ip addr"命令查看vip切換狀況 [root@master1 ~]# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:3c:25:42 brd ff:ff:ff:ff:ff:ff inet 182.148.15.238/27 brd 182.148.15.255 scope global eth0 inet 182.148.15.236/32 scope global eth0 //這個32位子網掩碼的vip地址表示該資源目前還在master1機器上 inet 182.148.15.236/27 brd 82.48.115.255 scope global secondary eth0:0 inet6 fe80::5054:ff:fe3c:2542/64 scope link valid_lft forever preferred_lft forever 中止master1機器上的mysql服務,根據配置中的腳本,mysql服務停了,keepalived也會停,從而vip資源將會切換到master2機器上。(mysql服務沒有起來的時候,keepalived服務也沒法順利啓動!) [root@master1 ~]# /etc/init.d/mysql stop Shutting down MySQL.. SUCCESS! [root@master1 ~]# ps -ef|grep mysql root 25812 21588 0 17:30 pts/0 00:00:00 grep mysql [root@master1 ~]# ps -ef|grep keepalived root 25814 21588 0 17:30 pts/0 00:00:00 grep keepalived [root@master1 ~]# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:3c:25:42 brd ff:ff:ff:ff:ff:ff inet 182.148.15.238/27 brd 182.148.15.255 scope global eth0 inet 182.148.15.236/27 brd 82.48.115.255 scope global secondary eth0:0 inet6 fe80::5054:ff:fe3c:2542/64 scope link valid_lft forever preferred_lft forever 如上結果,發現32位子網掩碼的vip沒有了,說明此時vip資源已不在master1機器上了 查看下master1的系統日誌,以下,會發現vip資源已經切換走了 [root@master1 ~]# tail -f /var/log/messages Apr 15 17:17:43 localhost Keepalived_vrrp[23037]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:17:48 localhost Keepalived_vrrp[23037]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:17:48 localhost Keepalived_vrrp[23037]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on eth0 for 182.148.15.236 Apr 15 17:17:48 localhost Keepalived_vrrp[23037]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:17:48 localhost Keepalived_vrrp[23037]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:17:48 localhost Keepalived_vrrp[23037]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:17:48 localhost Keepalived_vrrp[23037]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:39 localhost Keepalived_healthcheckers[23036]: Stopped Apr 15 17:30:39 localhost Keepalived_vrrp[23037]: VRRP_Instance(VI_1) sent 0 priority Apr 15 17:30:39 localhost Keepalived_vrrp[23037]: VRRP_Instance(VI_1) removing protocol VIPs. 再到master2機器上,發現vip資源的確切換過來了 [root@master2 ~]# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:95:1f:6d brd ff:ff:ff:ff:ff:ff inet 182.148.15.237/27 brd 182.148.15.255 scope global eth0 inet 182.148.15.236/32 scope global eth0 inet6 fe80::5054:ff:fe95:1f6d/64 scope link valid_lft forever preferred_lft forever 查看master2的系統日誌 [root@master2 ~]# tail -f /var/log/messages Apr 15 17:30:41 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:41 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:41 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:41 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 3)再次啓動master1的mysql和keepalived服務。(注意:若是restart重啓mysql,那麼還要啓動下keepalived,由於mysql重啓,根據腳本會形成keepalived關閉) 注意:必定要先啓動mysql服務,而後再啓動keepalived服務。若是先啓動keepalived服務,按照上面的配置,mysql沒有起來,就會自動關閉keepalived。 [root@master1 ~]# /etc/init.d/mysql start Starting MySQL.. SUCCESS! [root@master1 ~]# /etc/init.d/keepalived start 正在啓動 keepalived: [肯定] 啓動這兩個服務器後,稍微等過一下子,注意觀察會發現vip資源再次從master2機器上切換回來了。 [root@master1 ~]# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:3c:25:42 brd ff:ff:ff:ff:ff:ff inet 182.148.15.238/27 brd 182.148.15.255 scope global eth0 inet 182.148.15.236/32 scope global eth0 inet 182.148.15.236/27 brd 82.48.115.255 scope global secondary eth0:0 inet6 fe80::5054:ff:fe3c:2542/64 scope link valid_lft forever preferred_lft forever [root@master1 ~]# tail -f /var/log/messages Apr 15 17:40:41 localhost Keepalived_vrrp[27002]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:40:41 localhost Keepalived_vrrp[27002]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:40:41 localhost Keepalived_vrrp[27002]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:40:41 localhost Keepalived_vrrp[27002]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:40:46 localhost Keepalived_vrrp[27002]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:40:46 localhost Keepalived_vrrp[27002]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on eth0 for 182.148.15.236 Apr 15 17:40:46 localhost Keepalived_vrrp[27002]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:40:46 localhost Keepalived_vrrp[27002]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:40:46 localhost Keepalived_vrrp[27002]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:40:46 localhost Keepalived_vrrp[27002]: Sending gratuitous ARP on eth0 for 182.148.15.236 再看看master2機器,發現vip資源又被恢復後的master1搶過去了 [root@master2 ~]# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:95:1f:6d brd ff:ff:ff:ff:ff:ff inet 182.148.15.237/27 brd 182.148.15.255 scope global eth0 inet6 fe80::5054:ff:fe95:1f6d/64 scope link valid_lft forever preferred_lft forever [root@master2 ~]# tail -f /var/log/messages Apr 15 17:30:41 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: VRRP_Instance(VI_1) Sending/queueing gratuitous ARPs on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:30:46 localhost Keepalived_vrrp[8731]: Sending gratuitous ARP on eth0 for 182.148.15.236 Apr 15 17:40:41 localhost Keepalived_vrrp[8731]: VRRP_Instance(VI_1) Received advert with higher priority 101, ours 99 Apr 15 17:40:41 localhost Keepalived_vrrp[8731]: VRRP_Instance(VI_1) Entering BACKUP STATE Apr 15 17:40:41 localhost Keepalived_vrrp[8731]: VRRP_Instance(VI_1) removing protocol VIPs. 4)一樣,關閉master1機器的keepalived服務,vip資源會自動切換到master2機器上。當master1的keepalived服務恢復後,會將vip資源再次切回來。 [root@master1 ~]# /etc/init.d/keepalived stop 中止 keepalived: [肯定] [root@master1 ~]# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:3c:25:42 brd ff:ff:ff:ff:ff:ff inet 182.148.15.238/27 brd 182.148.15.255 scope global eth0 inet 182.148.15.236/27 brd 82.48.115.255 scope global secondary eth0:0 inet6 fe80::5054:ff:fe3c:2542/64 scope link valid_lft forever preferred_lft forever 查看master2,發現vip切過來了 [root@master2 ~]# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:95:1f:6d brd ff:ff:ff:ff:ff:ff inet 182.148.15.237/27 brd 182.148.15.255 scope global eth0 inet 182.148.15.236/32 scope global eth0 inet6 fe80::5054:ff:fe95:1f6d/64 scope link valid_lft forever preferred_lft forever 再次恢復master1的keepalived服務,發現vip資源很快油切回來了。 [root@master1 ~]# /etc/init.d/keepalived start 正在啓動 keepalived: [肯定] [root@master1 ~]# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:3c:25:42 brd ff:ff:ff:ff:ff:ff inet 182.148.15.238/27 brd 182.148.15.255 scope global eth0 inet 182.148.15.236/32 scope global eth0 inet 182.148.15.236/27 brd 82.48.115.255 scope global secondary eth0:0 inet6 fe80::5054:ff:fe3c:2542/64 scope link valid_lft forever preferred_lft forever 在此查看master2,發現vip資源被切走了 [root@master2 ~]# ip addr 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 52:54:00:95:1f:6d brd ff:ff:ff:ff:ff:ff inet 182.148.15.237/27 brd 182.148.15.255 scope global eth0 inet6 fe80::5054:ff:fe95:1f6d/64 scope link valid_lft forever preferred_lft forever 以上在vip資源切換過程當中,對於客戶端鏈接mysql(使用vip鏈接)來講幾乎是沒有任何影響的。
------------------------------------舒適提示(Keepalived的搶佔和非搶佔模式)---------------------------------------bash
keepalive是基於vrrp協議在linux主機上以守護進程方式,根據配置文件實現健康檢查。 VRRP是一種選擇協議,它能夠把一個虛擬路由器的責任動態分配到局域網上的VRRP路由器中的一臺。 控制虛擬路由器IP地址的VRRP路由器稱爲主路由器,它負責轉發數據包到這些虛擬IP地址。 一旦主路由器不可用,這種選擇過程就提供了動態的故障轉移機制,這就容許虛擬路由器的IP地址能夠做爲終端主機的默認第一跳路由器。 keepalive經過組播,單播等方式(自定義),實現keepalive主備推選。工做模式分爲搶佔和非搶佔(經過參數nopreempt來控制)。 1)搶佔模式: 主服務正常工做時,虛擬IP會在主上,備不提供服務,當主服務優先級低於備的時候,備會自動搶佔虛擬IP,這時,主不提供服務,備提供服務。 也就是說,工做在搶佔模式下,不分主備,只管優先級。 如上配置,無論keepalived.conf裏的state配置成master仍是backup,只看誰的priority優先級高(通常而言,state爲MASTER的優先級要高於BACKUP)。 priority優先級高的那一個在故障恢復後,會自動將VIP資源再次搶佔回來!! 2)非搶佔模式: 這種方式經過參數nopreempt(通常設置在advert_int的那一行下面)來控制。無論priority優先級,只要MASTER機器發生故障,VIP資源就會被切換到BACKUP上。 而且當MASTER機器恢復後,也不會去將VIP資源搶佔回來,直至BACKUP機器發生故障時,才能自動切換回來。 千萬注意: nopreempt這個參數只能用於state爲backup的狀況,因此在配置的時候要把master和backup的state都設置成backup,這樣纔會實現keepalived的非搶佔模式! 也就是說: a)當state狀態一個爲master,一個爲backup的時候,加不加nopreempt這個參數都是同樣的效果。即都是根據priority優先級來決定誰搶佔vip資源的,是搶佔模式! b)當state狀態都設置成backup,若是不配置nopreempt參數,那麼也是看priority優先級決定誰搶佔vip資源,即也是搶佔模式。 c)當state狀態都設置成backup,若是配置nopreempt參數,那麼就不會去考慮priority優先級了,是非搶佔模式!即只有vip當前所在機器發生故障,另外一臺機器才能接管vip。即便優先級高的那一臺機器恢復 後也不會主動搶回vip,只能等到對方發生故障,纔會將vip切回來。
---------------------------------mysql狀態檢測腳本優化---------------------------------服務器
上面的mysql監測腳本有點過於簡單且粗暴,即腳本一旦監測到Master的mysql服務關閉,就馬上把keepalived服務關閉,從而實現vip轉移! 下面對該腳本進行優化,優化後,當監測到Master的mysql服務關閉後,就會將vip切換到Backup上(但此時Master的keepalived服務不會被暴力kill) 當Master的mysql服務恢復後,就會再次將VIP資源切回來! [root@master ~]# cat /opt/chk_mysql.sh #!/bin/bash MYSQL=/usr/local/mysql/bin/mysql MYSQL_HOST=localhost MYSQL_USER=root MYSQL_PASSWORD=123456 CHECK_TIME=3 #mysql is working MYSQL_OK is 1 , mysql down MYSQL_OK is 0 MYSQL_OK=1 function check_mysql_helth (){ $MYSQL -h $MYSQL_HOST -u $MYSQL_USER -p${MYSQL_PASSWORD} -e "show status;" >/dev/null 2>&1 if [ $? = 0 ] ;then MYSQL_OK=1 else MYSQL_OK=0 fi return $MYSQL_OK } while [ $CHECK_TIME -ne 0 ] do let "CHECK_TIME -= 1" check_mysql_helth if [ $MYSQL_OK = 1 ] ; then CHECK_TIME=0 exit 0 fi if [ $MYSQL_OK -eq 0 ] && [ $CHECK_TIME -eq 0 ] then pkill keepalived exit 1 fi sleep 1 done