centos7 mysql+MHA高可用安装

https://qiniu.wsfnk.com/%E7%AC%AC12%E8%AF%BE-4%E4%BC%81%E4%B8%9A%E5%B8%B8%E8%A7%81MySQL%E6%9E%B6%E6%9E%84%E5%BA%94%E7%94%A8%E5%AE%9E%E6%88%98%E4%B9%8BMHA%E6%9E%B6%E6%9E%84.pdf

一、配置主从同步

1.1 本例中主从ip及端口

Master：192.168.20.50:3306

Slave1：192.168.31.3:3306 （候选master）

Slave2：192.168.31.2:3306

1.2、安装mysql

wget -i -c http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm

yum -y install mysql57-community-release-el7-10.noarch.rpm

yum -y install mysql-community-server
systemctl start mysqld.service

grep "password" /var/log/mysqld.log

mysql -uroot -p  #登录

ALTER USER 'root'@'localhost' IDENTIFIED BY 'My2019..';

#因为安装了Yum Repository，以后每次yum操作都会自动更新，需要把这个卸载掉

yum -y remove mysql57-community-release-el7-10.noarch

1.3.Master配置参数

[mysqld]

user=mysql

pid_file               = /var/lib/mysql/mysqld.pid

socket                 = /var/lib/mysql/mysql.sock

port                    =

basedir                 = /usr

datadir                 = /var/lib/mysql

tmpdir                 = /tmp

log-bin                 = master-bin

log-bin-index           = master-bin.index

server_id               =

innodb_log_file_size         = 256M

expire-logs-days = 1
validate_password=off #取消密码验证

#mysql5.6已上的特性，开启gtid，必须主从全开
gtid_mode = on
enforce_gtid_consistency = 1
log_slave_updates = 1

#开启半同步复制否则自动切换主从的时候会报主键错误
plugin_load = "rpl_semi_sync_master=semisync_master.so;rpl_semi_sync_slave=semisync_slave.so"
loose_rpl_semi_sync_master_enabled = 1
loose_rpl_semi_sync_slave_enabled = 1
loose_rpl_semi_sync_master_timeout = 5000

1.4.在master创建一个复制用户

主节点：
mysql> create user repl_user;

所有主机上授权：

mysql> grant replication slave on *.*  to repl_user identified by 'tt123456';

mysql> flush privileges;

mysql>grant all on *.* to root identified by 'my'; #很重要

1.5. Slave1 配置参数

[mysqld]

pid_file = /var/lib/mysql/mysqld.pid
socket = /var/lib/mysql/mysql.sock

basedir=/usr
port=3306
user=mysql
tmpdir= /tmp
server_id= 2
relay_log_index = slave_relay_bin.index
relay_log= slave_relay_bin
innodb_log_file_size= 256M
expire-logs-days = 1

log-bin = mysql-bin （候选需要配）
log-bin-index = mysql-bin.index （候选需要配）
read_only=1
relay_log_purge=0 #（一主一丛不需要此项，两从及以上建议开次参数，防止切换为成主库的从库自动删除中继日志后，无法给其他从库应用这部分日志）

validate_password=off #取消密码验证

gtid_mode = on
enforce_gtid_consistency = 1
log_slave_updates = 1

#开启半同步复制否则自动切换主从的时候会报主键错误
plugin_load = "rpl_semi_sync_master=semisync_master.so;rpl_semi_sync_slave=semisync_slave.so"（候选需要配）
loose_rpl_semi_sync_master_enabled = 1（候选需要配）
loose_rpl_semi_sync_slave_enabled = 1（候选需要配）
loose_rpl_semi_sync_master_timeout = 5000（候选需要配）

1.6.连接Master和Slave

参考：https://blog.csdn.net/lichangzai/article/details/50423906

mysql> CHANGE MASTER TO

MASTER_HOST='192.168.31.3',
MASTER_PORT=3306,
MASTER_AUTO_POSITION=1,
MASTER_USER='repl_user',
MASTER_PASSWORD='tt123456';

#master_log_file='master-bin.000007',#5.6后不需要指定
#master_log_pos=194;

mysql> start slave;
mysql> show slave status\G;

1.7查看半同步是否开启

master：

mysql> show status like 'Rpl_semi_sync_master_status';

+-----------------------------+-------+

| Variable_name              | Value |

+-----------------------------+-------+

| Rpl_semi_sync_master_status | ON    |

+-----------------------------+-------+

slave：

mysql> show status like 'Rpl_semi_sync_slave_status';

+----------------------------+-------+

| Variable_name              | Value |

+----------------------------+-------+

| Rpl_semi_sync_slave_status | ON    |

+----------------------------+-------+

二、配置ssh公钥互信

2.1. 本例中manager节点和node节点ip

manager：192.168.20.50

node1：192.168.20.50

node2：192.168.31.3

node3：192.168.31.2

注：manager节点可以安装独立的服务器上，本例为了节省机器，manager安装在了主库（192.168.20.50）上.

2.2. 配置manager和node各节点间的root用户的ssh公钥互信

在三个 mysql 节点分别执行如下操作：（三个都有，包括自己ssh自己）

ssh-keygen -t rsa

ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.20.50

ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.31.2

ssh-copy-id -i /root/.ssh/id_rsa.pub root@192.168.31.3

三、安装 MHA 包

3.1. MHA安装

manager和node节点安装：

　　 #先安装依赖

      wget http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm

      rpm -ivh epel-release-latest-7.noarch.rpm

　 　yum install -y perl-DBD-MySQL perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager

　　 wget https://qiniu.wsfnk.com/mha4mysql-node-0.58-0.el7.centos.noarch.rpm

　　 rpm -ivh mha4mysql-node-0.58-0.el7.centos.noarch.rpm

manager上安装：

wget https://qiniu.wsfnk.com/mha4mysql-manager-0.58-0.el7.centos.noarch.rpm

　　 rpm -ivh mha4mysql-manager-0.58-0.el7.centos.noarch.rpm

3.2、MHA Manager 端配置

配置主配置文件

 vi /etc/mha/app1.cnf

[server default]

manager_workdir=/var/log/mha/app1

manager_log=/var/log/mha/app1/manager.log

user=root #mysql用户
password=my123456 #mysql密码
ssh_user=root
repl_user=repl_user
repl_password=tt123456
ping_interval=1
#master_binlog_dir= /var/lib/mysql,/var/log/mysql
#secondary_check_script=masterha_secondary_check -s 192.168.20.50 -s 192.168.31.3 -s 192.168.31.2
#master_ip_failover_script="/etc/mha/scripts/master_ip_failover"
#master_ip_online_change_script="/etc/mha/scripts/master_ip_online_change"
#report_script="/etc/mha/scripts/send_report"

[server1]#这里模块不注释，ssh测试会报错，不过没影响

hostname=192.168.20.50

port=

master_binlog_dir=/var/lib/mysql

candidate_master=

check_repl_delay=

[server2]

hostname=192.168.31.3

port=

master_binlog_dir=/var/lib/mysql

candidate_master=  #如果候选master有延迟的话，relay日志超过100m，failover切换不能成功，加上此参数后会忽略延迟日志大小。

check_repl_delay=

[server3]

hostname=192.168.31.2

port=

master_binlog_dir=/var/lib/mysql

ignore_fail=  #如果这个节点挂了，mha将不可用，加上这个参数，slave挂了一样可以用

no_master=  #从不将这台主机转换为master
PS:以上注释不能写在配置文件里，不然会报错

四、运行

4.1. 检查SSH配置

masterha_check_ssh --conf=/etc/masterha/app1/app1.cnf

4.2检查MHA当前配置

masterha_check_repl --conf=/etc/masterha/app1/app1.cnf

4.3启动mha

nohup masterha_manager --conf=/etc/masterha/app1/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/mha/app1/manager.log 2>&1 &

4.4查看状态

masterha_check_status --conf=/etc/masterha/app1/app1.cnf

4.5关闭mha

masterha_stop --conf=/etc/masterha/app1/app1.cnf

4.6查看日志

tail -f /etc/masterha/app1/mha_manager.log

4.7从库从新加入新主

grep "CHANGE MASTER TO MASTER" /var/log/mha/app1/manager.log | tail -1

五、Failover应用场景测试

自动failover测试

应用场景1：master dead后，MHA当时已经开启，候选Master库（Slave）会自动failover为Master.

后面我的主库改为192.168.31.3，在这机器执行：systemctl stop mysqld.service

然后192.168.20.50执行：mysql> show master status\G;

从库机器192.168.31.2执行：mysql> show slave status\G;

最后把原主库192.168.31.3修复成一个新的slave：

#查看具体修复语句
# grep "CHANGE MASTER TO MASTER"  /etc/masterha/app1/manager.log | tail -

   CHANGE MASTER TO MASTER_HOST='192.168.20.50',MASTER_PORT=, MASTER_LOG_FILE='master-bin.000009', MASTER_AUTO_POSITION=,MASTER_USER='repl_user', MASTER_PASSWORD='xxx';

mysql> CHANGE MASTER TO MASTER_HOST='192.168.20.50',MASTER_PORT=3306, MASTER_LOG_FILE='master-bin.000009', MASTER_AUTO_POSITION=1,MASTER_USER='repl_user', MASTER_PASSWORD='tt123456';

mysql>start slave;

mysql>show slave status\G;

验证。

报错

1.replicates is not defined in the configuration file!

masterha_check_repl --conf=/etc/masterha/app1/app1.cnf

Thu Jan  ::  - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.

Thu Jan  ::  - [info] Reading application default configuration from /etc/masterha/app1/app1.cnf..

Thu Jan  ::  - [info] Reading server configuration from /etc/masterha/app1/app1.cnf..

Thu Jan  ::  - [info] MHA::MasterMonitor version 0.58.

Thu Jan  ::  - [error][/usr/share/perl5/vendor_perl/MHA/ServerManager.pm, ln671] Master 192.168.20.50: from w

hich slave 192.168.31.2(192.168.31.2:) replicates is not defined in the configuration file!

Thu Jan  ::  - [error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm, ln427] Error happened on checking confi

gurations.  at /usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm line .

Thu Jan  ::  - [error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm, ln525] Error happened on monitoring ser

vers.

Thu Jan  ::  - [info] Got exit code  (Not master dead).

解决：配置文件里面没有manager的主机信息，添加上去。

[server1]

hostname=192.168.20.50

port=3306

master_binlog_dir=/var/lib/mysql

candidate_master=1

check_repl_delay=0

2、[error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm

[error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm, ln427] Error happened on checking confi

gurations. Argument "1  #M-dM-;M-^NM-dM-8M-\rM-eM-0M-^FM-hM-?M-^YM-eM-^OM-0M-d..." isn't numeric in numeric ge (>=) at /usr/s

hare/perl5/vendor_perl/MHA/ServerManager.pm line .

Thu Jan  ::  - [error][/usr/share/perl5/vendor_perl/MHA/MasterMonitor.pm, ln525] Error happened on monitoring ser

vers.
解决：
配置文件不能有中文注释。。