三．MHA架构
四．部署MHA 环境要求：四台虚拟机server1是master，server2是备选master，server3和server4是slave 在所有节点安装MHA Node所需的perl模块，需要软件包perl-DBD-Mysql 然后yum install 在所有节点安装mha node,需要软件包mha4mysql-node-0.53.tar.gz tar xf mha4mysql-node-0.53.tar.gz cd mha4mysql-node-0.53 Perl Makefile.PL make && make install 安装MHA Manager 首先安装MHA Manager依赖和perl模块 yum install perl-DBD-Mysql perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes -y 需要软件包mha4mysql-manager-0.53.tar.gz tar xf mha4mysql-manager-0.53.tar.gz cd mha4mysql-manager-0.53 Perl Makefile.PL make && make install 安装完成后在/usr/local/bin下生成脚本文件 进入 cd /root/mha4mysql-manager-0.53/samples/scripts下 将master_ip_failover master_ip_online_change复制到/usr/local/bin下，与之前生成的脚本合在一起 配置SSH登录无密码验证 搭建主从复制环境 在server2上执行备份：mysqldump --master-data=2 --sigle-transaction -R --triggers -A > all.sql --master-data=2 ##备份时刻记录master的binlog的位置和position --single-transaction ##获取一致性快照 -R ##备份存储过程和函数 --tiggers ##备份触发器 -A ##备份所有的库 在server2上创建复制用户：grant replication slave on *.* to ‘repl’@‘172.25.15.%’ identified by ‘westos’; flush privileges 查看主库备份时的binlog名称和位置，MASTER_LOG_FILE和MASTER_LOG_POS： Head -n 30 all.sql | grep ‘CHANGE MASTER TO’ 把备份复制到server3和server4 Scp all.sql server3:/data Scp all.sql server4:/data 导入备份到server3,执行复制相关命令 mysql < /data/all.sql CHANGE MASTER TO MASTER—HOST=‘172.2515.3’，MASTER_USER=‘repl’,MASTER_PASSWORD=‘westos’,MASTER_LOG_FILE=‘mysql-bin.000010’,MASTER_LOG_POS=112; start slave 在server4上也搭建复制环境 mysql < /data/all.sql CHANGE MASTER TO MASTER—HOST=‘172.2515.3’，MASTER_USER=‘repl’,MASTER_PASSWORD=‘westos’,MASTER_LOG_FILE=‘mysql-bin.000010’,MASTER_LOG_POS=112; start slave 两台slave服务器server3和server4设置read_only Mysql -e ‘set global read_only=1’ 在master上创建监控用户 Grant all privileges on *.* to ‘root’@‘172.25.15.%’identified by ‘westos’; flush privileges 集群环境搭建完毕 五．配置MHA 创建MHA工作目录，并且创建相关配置文件 mkdir -p /etc/mastermha cp mha4mysql-manager-0.53/samples/conf/appl.cnf /etc/mastermha 修改app1.cnf配置文件 manager_workdir=/var/log/mastermha/app1.log ##设置manager的工作目录 manager_log=/var/log/mastermha/app1.log ##设置manager的日志 master_binlog_dir=/data/mysql ##设置master保存binlog的位置 master_ip_failover_script=/usr/local/bin/master_ip_failover ##设置自动failover时候的切换脚本 master_ip_online_change_script=/usr/local/bin/master_ip_online_change ##设置手动切换时候的切换脚本 password=westos ##设置mysql中root用户的密码 user=root ##设置监控用户root ping_interval=1 ##设置监控主库，发送ping包的时间间隔默认是3秒，尝试3次没有回应的时候自动进行railover remote_workdir=/tmp ##设置远端mysql在发生切换时binlog的保存位置 repl_password=westos ##设置复制用户的密码 repl_user=repl ##设置复制环境中的复制用户名 report_script=/usr/local/send_report ##设置发生切换后发送的报警的脚本 secondary_check_script=/usr/local/bin/mastermha_secondary_check -s server3 -s server2 shutdown_script=“” ##设置故障发生后关闭故障主机脚本 ssh_user=root ##设置ssh的登录用户名 [server1] hostname=172.25.15.1 port=3306 [server2] hostname=172.25.15.2 port=3306 candidate_master=1 ##设置为候选master。如果设置该参数以后，发生主从切换以后将会将此从库提升为主库，即使这个主库不是集群中最新的slave check_repl_delay=0 ##默认情况下如果一个slave落后master100M的relay logs的话 [server3] hostname=172.25.15.3 port=3306 修改完成 检查ssh配置 mastermaha_check_ssh --conf=/etc/mastermha/app1.cnf 检查整个复制环境状况 mastermaha_check_repl --conf=/etc/mastermha/app1.cnf 检查MHA Manager的状态 mastermaha_check_status --conf=/etc/mastermha/app1.cnf 开启MHA Manager监控 nohup mastermha_manager --conf=/etc/mastermha/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/mastermha/app1/manager.log 2>&1 & --remove_dead_master_conf ##该参数表示当发生主从切换后，老的主库的ip将会从配置文件中移除 --manager.log ##日志存放位置 --ignore_last_failover ##缺省情况下，MHA监测到连续宕机，且两次间隔不足8小时，则不会进行failover 六．配置vip 配置vip可以采用两种方式，一种通过keepalived的方式，另一种通过脚本方式启动虚拟ip 需要软件包keepalived-1.2.12.tar.gz tar xf keepalived-1.2.12.tar.gz cd keepalived-1.2.12 ./configure --prefix=/usr/local/keepalived make && make install cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig mkdir /etc/keepalived cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived cp /usr/local/keepalived/sbin/keepalived /usr/sbin 在master配置keepalived的配置文件 Vim /etc/keepalived/keepalived.conf Global_defs { notification_email { root@localhost } notification_email_from dba@dbaserver.com smtp_server 127.0.0.1 Smtp_connect_timeout 30 router_id Mysql-HA } vrrp_instance VI_1 { state BACKUP interface eth1 virtual_router_id 51 priority 150 advert_int 1 nopreempt authentication { auth_type PASS auth_pass 1111 } Virtual_ipaddress { 172.25.15.100 router_id Mysql-HA ##设定keepalived组的名称 172.25.15.100这个虚拟IP绑定到该主机的eth1网卡上，并且设置为backup状态 在候选master上也如此配置，但优先级更低 启动keepalived服务 /etc/init.d/keepalived start 七．MHA引入keepalived 在主库上编辑脚本/usr/local/bin/master_ip_failover #!/usr/bin/env perl 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 = '172.25.0.100/24'; my $key = '1'; my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip"; my $ssh_stop_vip = "/sbin/ifconfig eth0:$key down"; 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 \" $ssh_start_vip \"`; } sub stop_vip() { return 0 unless ($ssh_user); `ssh $ssh_user\@$orig_master_host \" $ssh_stop_vip \"`; } sub usage { Print 检查集群状态 master_check_repl --conf=/etc/mastermha/app1.cnf 八．MHA的工作情况 1.自动failover 开启slave上的IO线程 start slave io_thread 杀掉主库mysql进程,进行自动failover kill -9 mysqld 2.手动failover 手动切换命令 mastermha_master_switch --master_state=dead --conf=/etc/mastermha/app1.cnf --dead_master_host=172.25.15.1 --dead_master_port=3306 --new_master_host=172.25.15..2 --new_master_port=3306 --ignore_last_failover 3.在线切换 停掉MHA监控 master_stop --conf=/etc/mastermha/app1.cnf 在线切换操作 mastermha_master_switch --conf=/etc/mastermha/app1.cnf --master_state=alive --new_master_host=172.25.15.2 --new_master_port=3306 --orig_master_is_new_slave --running_update_limit=10000 --orig_master_is_new_slave ##将原master变为slave --running_update_limit=10000 ##故障切换时，延迟在此时间范围内都可切换
