文章目錄
前言
- MHA目前在MySQL高可用方面是一個相對成熟的解決方案
- 但是在搭建的過程中會經常報錯,且MHA的構建綜合了主從複製,所以MHA的安裝要思路清晰纔可
一:MHA概述
1.1:什麼是MHA?
- 日本DeNA公司 youshimaton(現就職於 Facebook公司)開發
- 一套優秀的作爲MySQL高可用性環境下故障切換和主從提升的高可用軟件
- 支持故障切換
- 在MySQL故障切換過程中,MHA能做到在0~30秒之內自動完成數據庫的故障切換操作,並且在進行故障切換的過程中,MHA能在最大程度上保證數據的一致性,以達到真正意義上的高可用
- MHA還提供在線主庫切換的功能,能夠安全地切換當前運行的主庫到一個新的主庫中(通過將從庫提升爲主庫),大概0.5-2秒內即可完成
1.2:MHA的組成
- MHA Manager(管理節點)
- 用來接收外部信號,監控下方數據節點的工作狀態
- MHA Node(數據節點)
- 工作的單位,負責具體的工作
1.3:MHA有什麼特點?
- 自動故障切換過程中,MHA試圖從宕機的主服務器上保存二進制日誌,最大程度的保證數據的不丟失
- 使用 MySQL55的半同步複製,可以大大降低數據丟失的風險
1.4:MHA形成的原因
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傳統mysql主從架構存在單點故障的問題
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傳統架構中,只有一個mysql主服務器,所以當出現單點故障的時候,整個服務器羣集就會癱瘓掉
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爲了解決這種情況,我們需要在主服務器宕機的時候,重新建立一臺主服務器,負責監控等工作
二:MHA實驗
2.1:實驗環境
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VMware軟件
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一臺centos7作爲MHA
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三臺centos7作爲mysql服務器
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搭建好mysql主從複製環境
沒有搭建的可以看我之前的博客
https://blog.csdn.net/CN_TangZheng/article/details/103897251
2.2:拓撲圖
2.3:實驗目的
- 通過MHA監控MySQL數據庫,在故障時自動進行切換,不影響業務
- 當主庫失效時,備選主庫自動成爲主庫
2.4:實驗過程
- 因爲操作系統是centos7,所以要下載MHA 0.57版本
2.4.1:安裝gmake編譯軟件
[root@slave2 ~]# mount.cifs //192.168.11.11/ccc /mnt
Password for root@//192.168.11.11/ccc:
[root@slave2 ~]# cd /mnt/shuju數據庫/mha
[root@slave2 mha]#
[root@slave2 mha]# tar zxvf cmake-2.8.6.tar.gz -C /opt
[root@slave2 mha]# cd /opt/cmake-2.8.6/
[root@slave2 cmake-2.8.6]# ./configure
[root@slave1 cmake-2.8.6]# gmake
[root@slave1 cmake-2.8.6]# gmake install
2.4.2:搭建mysql主從複製環境
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https://blog.csdn.net/CN_TangZheng/article/details/103897251
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記得關閉防火牆
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主從複製環境中的mysql同步的用戶名爲:myslave 密碼:123456
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額外調整
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所有數據庫授權mha用戶對數據庫的操作權限,每一個mysql數據庫都要設置
'//下面三條授權按理論是不用添加的,但是做案例實驗環境時候誦過MHA檢查MySQL主從有報錯,報兩個從庫通過主機名連接不上主庫,所以所有數據庫加上下面的授權;' mysql> grant all privileges on *.* to 'mha'@'master' identified by 'manager'; mysql> grant all privileges on *.* to 'mha'@'slave1' identified by 'manager'; mysql> grant all privileges on *.* to 'mha'@'slave2' identified by 'manager'; '//三臺mysql服務器的授權增加一個給mha管理' mysql> grant all privileges on *.* to 'mha'@'192.168.79.%' identified by 'manager'; '//主備mysql服務器添加用戶和權限' '//192.168.79.0段的從服務器擁有複製權限,可以使用myslave身份123456密碼複製所有的庫和表' mysql> GRANT REPLICATION SLAVE ON *.* TO 'myslave'@'192.168.79.%' IDENTIFIED BY '123456';
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slave1和slave2兩個從數據庫設置爲只讀
mysql> set global read_only=1;
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所有slave節點配置二進制日誌,註釋掉client段的默認字符集
[root@slave1 ~]# vim /etc/my.cnf [mysqld]段落添加 log-bin=slave1-bin '//添加二進制日誌' 所以slave節點都要配置,我就不一一展示了 '//從服務器上都註釋掉client段的默認字符集' [root@slave1 ~]# vim /etc/my.cnf [client] #default-character-set=utf8 '//註釋掉此'
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創建軟連接
所有節點創建軟連接 ln -s /usr/local/mysql/bin/mysqlbinlog /usr/local/bin/ 創建mysql軟連接 ln -s /usr/local/mysql/bin/mysql /usr/local/bin/
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2.4.3:所有節點安裝環境和Node組件和Manager組件
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所有服務器上都要安裝mha依賴的環境,此處僅展示mha_manager的安裝
[root@mha_manager ~]# yum install epel-release --nogpgcheck -y [root@mha_manager ~]# yum install -y perl-DBD-MySQL \ perl-Config-Tiny \ perl-Log-Dispatch \ perl-Parallel-ForkManager \ perl-ExtUtils-CBuilder \ perl-ExtUtils-MakeMaker \ perl-CPAN
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所有服務器都安裝安裝node組件,此處僅展示master服務器的安裝
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[root@master ~]# tar zxvf /mnt/shuju數據庫/mha/mha4mysql-node-0.57.tar.gz [root@master ~]# cd mha4mysql-node-0.57/ [root@master mha4mysql-node-0.57]# yum install perl-Module-Install -y [root@master mha4mysql-node-0.57]# perl Makefile.PL ==> Auto-install the 1 mandatory module(s) from CPAN? [y] y '//輸入y' [root@master mha4mysql-node-0.57]# make [root@master mha4mysql-node-0.57]# make install
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僅mha_manager服務器安裝manager組件
[root@mha_manager ~]# tar zxvf /mnt/shuju數據庫/mha/mha4mysql-manager-0.57.tar.gz [root@mha_manager ~]# cd mha4mysql-manager-0.57/ [root@mha_manager mha4mysql-manager-0.57]# perl Makefile.PL [root@mha_manager mha4mysql-manager-0.57]# make [root@mha_manager mha4mysql-manager-0.57]# make install
2.4.4:配置節點間SSH面交互登陸
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mha_manager主機配置到所有數據庫節點的密鑰對驗證
[root@mha_manager ~]# ssh-keygen -t rsa '//創建非對稱密鑰對' '//因爲想要免密登陸,所以三個都直接回車就行,不需要設置密碼' Enter file in which to save the key (/root/.ssh/id_rsa): Enter passphrase (empty for no passphrase): Enter same passphrase again: '//上傳祕鑰到節點服務器' [root@mha_manager ~]# ssh-copy-id 192.168.79.134 Are you sure you want to continue connecting (yes/no)? yes [email protected]'s password: //輸入密碼' '//相同方法建立其他服務器' [root@mha_manager ~]# ssh-copy-id 192.168.79.135 [root@mha_manager ~]# ssh-copy-id 192.168.79.136
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在master上配置到數據庫節點slave1和slave2的免密驗證
[root@master mha4mysql-node-0.57]# ssh-keygen -t rsa '//創建非對稱密鑰對' '//用上述方法建立其他服務器' [root@master mha4mysql-node-0.57]# ssh-copy-id 192.168.79.135 [root@master mha4mysql-node-0.57]# ssh-copy-id 192.168.79.136
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在slave1上配置到數據庫節點master和slave2的免密驗證
[root@slave1 ~]# ssh-keygen -t rsa [root@slave1 ~]# ssh-copy-id 192.168.79.134 [root@slave1 ~]# ssh-copy-id 192.168.79.136
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在slave2上配置到數據庫節點master和slave1的免密驗證
[root@slave2 ~]# ssh-keygen -t rsa [root@slave2 ~]# ssh-copy-id 192.168.79.134 [root@slave2 ~]# ssh-copy-id 192.168.79.135
2.4.5:配置MHA-Manager組件
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複製相關腳本到/usr/local/bin目錄
[root@mha_manager ~]# cp -ra /root/mha4mysql-manager-0.57/samples/scripts /usr/local/bin [root@mha_manager samples]# ls -l /usr/local/bin/scripts/ -rwxr-xr-x. 1 1001 1001 3648 5月 31 2015 master_ip_failover 自動切換時 VIP管理的腳本 -rwxr-xr-x. 1 1001 1001 9870 5月 31 2015 master_ip_online_change 在線切換VIP的管理 -rwxr-xr-x. 1 1001 1001 11867 5月 31 2015 power_manager 故障發生後關閉主機的腳本 -rwxr-xr-x. 1 1001 1001 1360 5月 31 2015 send_report 因故障切換後發送報警的腳本 [root@mha_manager ~]# cp /usr/local/bin/scripts/master_ip_failover /usr/local/bin/ '//自動切換時 VIP管理的腳本'
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修改master_ip_failover 腳本
[root@mha_manager ~]# vim /usr/local/bin/master_ip_failover '//刪除內容,重新編寫腳本' #!/usr/bin/env perl '//第一行要最頂行寫,不要有空格' use strict; use warnings FATAL => 'all'; use Getopt::Long; my ( $command, $ssh_user, $orig_master_host, $orig_master_ip, $orig_master_port, $new_master_host, $new_master_ip, $new_master_port ); my $vip = '192.168.79.100'; my $brdc = '192.168.79.255'; my $ifdev = 'ens33'; my $key = '1'; my $ssh_start_vip = "/sbin/ifconfig ens33:$key $vip"; my $ssh_stop_vip = "/sbin/ifconfig ens33:$key down"; my $exit_code = 0; #my $ssh_start_vip = "/usr/sbin/ip addr add $vip/24 brd $brdc dev $ifdev label $ifdev:$key;/usr/sbin/arping -q -A -c 1 -I $ifdev $vip;iptables -F;"; #my $ssh_stop_vip = "/usr/sbin/ip addr del $vip/24 dev $ifdev label $ifdev:$key"; GetOptions( 'command=s' => \$command, 'ssh_user=s' => \$ssh_user, 'orig_master_host=s' => \$orig_master_host, 'orig_master_ip=s' => \$orig_master_ip, 'orig_master_port=i' => \$orig_master_port, 'new_master_host=s' => \$new_master_host, 'new_master_ip=s' => \$new_master_ip, 'new_master_port=i' => \$new_master_port, ); exit &main(); sub main { print "\n\nIN SCRIPT TEST====$ssh_stop_vip==$ssh_start_vip===\n\n"; if ( $command eq "stop" || $command eq "stopssh" ) { my $exit_code = 1; eval { print "Disabling the VIP on old master: $orig_master_host \n"; &stop_vip(); $exit_code = 0; }; if ($@) { warn "Got Error: $@\n"; exit $exit_code; } exit $exit_code; } elsif ( $command eq "start" ) { my $exit_code = 10; eval { print "Enabling the VIP - $vip on the new master - $new_master_host \n"; &start_vip(); $exit_code = 0; }; if ($@) { warn $@; exit $exit_code; } exit $exit_code; } elsif ( $command eq "status" ) { print "Checking the Status of the script.. OK \n"; exit 0; } else { &usage(); exit 1; } } sub start_vip() { `ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`; } # A simple system call that disable the VIP on the old_master sub stop_vip() { `ssh $ssh_user\@$orig_master_host \" $ssh_stop_vip \"`; } sub usage { print "Usage: master_ip_failover --command=start|stop|stopssh|status --orig_master_host=host --orig_master_ip=ip --orig_master_port=port --new_master_host=host --new_master_ip=ip --new_master_port=port\n"; }
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創建MHA軟件目錄並拷貝配置文件
[root@mha_manager ~]# mkdir /etc/masterha [root@mha_manager ~]# cp /root/mha4mysql-manager-0.57/samples/conf/app1.cnf /etc/masterha/ [root@mha_manager ~]# vim /etc/masterha/app1.cnf '//刪除內容,重新編寫腳本' [server default] manager_log=/var/log/masterha/app1/manager.log manager_workdir=/var/log/masterha/app1 master_binlog_dir=/usr/local/mysql/data master_ip_failover_script=/usr/local/bin/master_ip_failover master_ip_online_change_script=/usr/local/bin/master_ip_online_change password=manager ping_interval=1 remote_workdir=/tmp repl_password=123456 repl_user=myslave secondary_check_script=/usr/local/bin/masterha_secondary_check -s 192.168.79.135 -s 192.168.79.136 shutdown_script="" ssh_user=root user=mha [server1] hostname=192.168.79.134 port=3306 [server2] candidate_master=1 hostname=192.168.79.135 check_repl_delay=0 port=3306 [server3] hostname=192.168.79.136 port=3306
2.4.6:測試SSH與mysql主從連接
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驗證密鑰對
[root@mha_manager ~]# masterha_check_ssh -conf=/etc/masterha/app1.cnf Fri Jan 10 01:14:10 2020 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping. Fri Jan 10 01:14:10 2020 - [info] Reading application default configuration from /etc/masterha/app1.cnf.. Fri Jan 10 01:14:10 2020 - [info] Reading server configuration from /etc/masterha/app1.cnf.. Fri Jan 10 01:14:10 2020 - [info] Starting SSH connection tests.. Fri Jan 10 01:14:11 2020 - [debug] Fri Jan 10 01:14:10 2020 - [debug] Connecting via SSH from [email protected].135(192.168.79.135:22) to [email protected].136(192.168.79.136:22).. Fri Jan 10 01:14:11 2020 - [debug] ok. Fri Jan 10 01:14:12 2020 - [debug] Fri Jan 10 01:14:10 2020 - [debug] Connecting via SSH from [email protected].136(192.168.79.136:22) to [email protected].135(192.168.79.135:22).. Fri Jan 10 01:14:11 2020 - [debug] ok. Fri Jan 10 01:14:12 2020 - [info] All SSH connection tests passed successfully.
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測試mysql主從連接
[root@mha_manager ~]# masterha_check_repl -conf=/etc/masterha/app1.cnf
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相關報錯,請查閱我的博客
https://blog.csdn.net/CN_TangZheng/article/details/103925515
2.4.7:配置虛擬IP,啓動MHA
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添加虛擬IP
[root@master ~]# /sbin/ifconfig ens33:1 192.168.79.100/24
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啓動MHA
[root@mha_manager ~]# nohup masterha_manager --conf=/etc/masterha/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > [root@mha_manager ~]# /var/log/masterha/app1/manager.log 2>&1 & '//查看到當前的master節點是誰' [root@mha_manager ~]# masterha_check_status --conf=/etc/masterha/app1.cnf '//查看當前日誌信息' [root@mha_manager ~]# cat /var/log/masterha/app1/manager.log
2.4.8:模擬故障
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啓動監控觀察日誌記錄
[root@mha_manager ~]# tailf /var/log/masterha/app1/manager.log
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關掉master服務器
[root@master ~]# pkill -9 mysqld
2.5:實驗驗證
2.5.1:主服務器變更成功
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此時發現主服務器已經變更
slave1查看
[root@slave1 ~]# ifconfig ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.79.135 netmask 255.255.255.0 broadcast 192.168.79.255 inet6 fe80::159a:a8d1:5769:74d0 prefixlen 64 scopeid 0x20<link> ether 00:0c:29:34:57:c1 txqueuelen 1000 (Ethernet) RX packets 347068 bytes 28229347 (26.9 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 528201 bytes 67755670 (64.6 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 ens33:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.79.100 netmask 255.255.255.0 broadcast 192.168.79.255 ether 00:0c:29:34:57:c1 txqueuelen 1000 (Ethernet)
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mha_manager查看
'//會動態顯示後續信息' Generating relay diff files from the latest slave succeeded. 192.168.79.136(192.168.79.136:3306): OK: Applying all logs succeeded. Slave started, replicating from 192.168.79.135(192.168.79.135:3306) 192.168.79.135(192.168.79.135:3306): Resetting slave info succeeded. Master failover to 192.168.79.135(192.168.79.135:3306) completed successfully.
2.5.2:嘗試從客戶端通過虛擬IP連接上數據庫
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直接在mha_manager上安裝mysql
[root@mha_manager ~]# yum install mysql -y
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在vip的數據庫服務器上提取
[root@slave1 ~]# mysql -uroot -p Enter password: mysql> grant all on *.* to 'root'@'%' identified by 'abc123';
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在客戶機(mha_manager)上用虛擬IP進行登錄
[root@mha_manager ~]# mysql -h 192.168.79.100 -uroot -pabc123 MySQL [(none)]> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | yiku | | mysql | | performance_schema | | erku | | sanku | | sys | +--------------------+ 8 rows in set (0.00 sec)