MySQL-MMM的读写分离及高可用

用途
 mmm是基于信息探测方式进行mysql主从复制架构的监测与故障转移
 mmm可以做到负载均衡,100%的数据可用性
 mmm所涉及的检查项   服务器可达性,服务可达性,复制线程可控性

 如图: 当 master1在宕机时, mmm可以将之前分摊的流量进行转移,甚至于将从服务器提升为主

延续双主模型.

mmm-agent端状态一览
   online 节点可用
   replication_delay 复制延迟或无法进行(检查req_backlog文件)
   replication_fail 复制失败
   awating_recovery 等待恢复
   hard_offline  主机离线
   admin_offline  主控端离线
   unknown  未知错误

规划如下
172.16.43.200  主控机器负责监测与资源的管理
172.16.43.1  vip(172.16.43.11)  master1 主主复制第一台(可读写)
172.16.43.2  vip(172.16.43.12)  master2 主主复制第二台(只读)
172.16.43.3  vip(172.16.43.13)  slave   主从方式复制 1 , 2 的信息(只读)

实验过程如下

主控安装安装: ansible, mysql客户端, mysql-mmm
集群节点安装如下: mariadb, mysql-agent

i)  主机互信,ansible部署的关键

yum -y install ansible-1.5.4-1.el6.noarch.rpm
vim /etc/ansible/hosts
# 主控节点完成
[masterserver]
master1.king.com
master2.king.com
.
[slaveserver]
slave.king.com
# 主控节点完成互信多个被管理节点不重复了
ssh-keygen -t rsa
ssh-copy-id -i .ssh/id_rsa.pub [email protected]
.
# 主控节点完成安装mysql-mmm*
yum -y install mysql mysql-mmm*
.
# 实现mmm配置文件有两种
# 1. 主控端   mmm_common, mmm_mon
# 2. 集群端   mmm_common, mmm_agent
# 主控端配置common   /etc/mysql-mmm/mmm_common.conf
active_master_role  writer
.

cluster_interface       eth0
pid_path                /var/run/mysql-mmm/mmm_agentd.pid
bin_path                /usr/sbin
replication_user        repl
replication_password    repl
agent_user              mmm_agent
agent_password          agent_password

.

ip 172.16.43.1
mode master
peer master2

.

ip 172.16.43.2
mode master
peer master1

.

ip 172.16.43.3
mode slave

.
# 谁能写  vip是多少(参照本文配置)

hosts master1, master2
ips 172.16.43.11
mode exclusive

.
# 谁能读  vip是多少(参照本文配置)

hosts master1, master2
ips 172.16.43.11, 172.16.43.12, 172.16.43.13
mode balanced

.
# 主控节点完成
vim /etc/mysql-mmm/mmm_mon.conf
# 需要改 ping_ips, 把你想监控的集群加入进入就可以了
# 172.16.0.1 是网关ip
ping_ips 172.16.0.1, 172.16.43.1, 172.16.43.2, 172.16.43.3
.

    monitor_user        mmm_monitor
    monitor_password    monitor_password

ii) 安装 mariadb, mysql-agent安装与配置

# 编写 install.yaml, 使用ansible-playbook执行按成安装配置
- hosts: masterserver:slaveserver
  remote_user: root
  tasks:
    - name: mariadb install
      copy: src=/root/mariadb-10.0.10-linux-x86_64.tar.gz dest=/tmp
    - name: conf service
      command: tar xf /tmp/mariadb-10.0.10-linux-x86_64.tar.gz -C /usr/local
    ###############################################################
    # 见谅下面的 name: x , 写了半天才知道不能在一个name中包含多个command,所以..  #
    ###############################################################
    - name: 1
      command: ln -sv /usr/local/mariadb-10.0.10-linux-x86_64 /usr/local/mysql
    - name: 2
      command: cp /usr/local/mysql/support-files/mysql.server /etc/rc.d/init.d/mysqld
    - name: 3
      command: chmod +x /etc/rc.d/init.d/mysqld
    - name: 4
      command: mkdir /mydata/data -p
    - name: 5
      command: mkdir /mydata/binlogs -p
    - name: 6
      command: mkdir /mydata/relaylogs -p
    - name: 7
      command: useradd -r -s /sbin/nologin mysql -U
    - name: 8
      command: chown mysql.mysql /mydata -R
    - name: 9
      command: chown mysql.mysql /usr/local/mysql -R
    - name: 9-1
      # 将本地配置好的安装文件移植到集群节点, 解压的配置文件可能不符合要求
      copy: src=/usr/local/mysql/scripts/mysql_install_db dest=/usr/local/mysql/scripts/
    - name: 10
      command: /usr/local/mysql/scripts/mysql_install_db --user=mysql --datadir=/mydata/data
    - name: mariadb conf
      # 此处配置文件 /etc/my.cnf 配置好
      # log-bin=/mydata/binlogs/mysql-bin
      # relay-log=/mydata/relaylogs/relay-bin
      # datadir=/mydata/data
      copy: src=/etc/my.cnf dest=/etc/my.cnf
      notify:
        - restart mariadb
    - name: install mysql-mmm-agent
      yum: name=mysql-mmm-agent state=present
    - name: conf mysql-mmm-agent
      copy: src=/etc/mysql-mmm/mmm_common.conf dest=/etc/mysql-mmm
    - name: modify mmm_agent.conf
      command: sed -i 's@^\(this[[:space:]]\).*@\1` item `@' /etc/mysql-mmm/mmm_agent.conf
      with_items:
        - master1
        - master2
        - slave
    - name: 11
      command: sed -i 's@^\(ENABLED=\).*@\11@' /etc/default/mysql-mmm-agent
  handlers:
    - name: restart mariadb
      service: name=mysqld state=restarted

不熟yaml的童鞋可以 yaml.org

iii) 实现双主复制与主从复制

1. 双主配置 (master1.king.com , master2.king.com)
vim /etc/my.cnf
service-id  = 1 | 2 (不可相同分别设置)
log-slave-updates = 1
*** 自动增长列的配置要隔开
auto-increment-offset = 1
auto-increment-increment = 2
2. 均授权复制账号给对方, 进入命令行
mysql> grant replication client, replication slave on *.* to repl@'172.16.%.%' identified by 'repl';
mysql> flush privileges;
3. 均授权监控账号
mysql> grant replication client on *.* to 'mmm_monitor'@'172.16.%.%' identified by 'monitor_password';
mysql> grant super, replication client, process on *.* to 'mmm_agent'@'172.16.%.%' identified by 'agent_password';
4. 均连接对方服务器
mysql> change master to master_host='172.16.43.1',master_user='repl', master_password='repl', master_log_file='mysql-bin.000001', master_log_pos=312;
5. 均启动复制线程
mysql> start salve;
.
.
# 主从复制 (slave.king.com)
1、改server-id 配置文件中
vim /etc/my.cnf
server-id       = 3
2, 授权监控账号,进入命令行 mysql
mysql> grant replication client on *.* to 'mmm_monitor'@'172.16.%.%' identified by 'monitor_password';
mysql> grant super, replication client, process on *.* to 'mmm_agent'@'172.16.%.%' identified by 'agent_password';
3、连接主服务器
mysql> change master to master_host='172.16.43.1',master_user='repl', master_password='repl', master_log_file='mysql-bin.000001', master_log_pos=312;
4、启动复制线程
mysql> start slave;

iv) 启动测试

# mmm的停止与启动
/etc/init.d/mysql-mmm-agent stop | start
/etc/init.d/mysql-mmm-monitor stop | start
.
# 离线或上线一个节点
mmm_control set_offline master1
mmm_control set_online master1
.
# 查看节点状态
mmm_control show

测试1

如图: 让 master2 离线,读写均不受影响 (抱歉此图没有截图下来,,但最后结果图中有所显示  : )

测试2:

再来一次测试,将master1主节点下线,我们观察一下情况, 在图中我们可以看到读写资源已经迁移到了master2节点

总结

经过测试可以看出MMM在mysql的高可用表现非常良好,无论是只剩一主还是一主一从,数据的同步确实比较及时准确

生产环境还需观察...