MySQL主从replication半同步设置及支持基于ssl复制配置


一、mysql的主从复制过程:

     master中的dump进程将二进制文件读出,具有此服务器中replication client 和replication slave权限的从服务器的I/O 线程
  读入主服务器的二进制文件并记录到relay-log中,从服务器的sql线程按照my.cnf中定义的规则,去读取relay-log,并更新到数据库中
  
 由上述过程可知,master维护bin-log ,slave维护relay-log 从而实现主从复制
 
 主从实现:
    主服务器中的配置 (172.16.21.1)
#vim my.cnf
[mysqld]
  server-id=1
  sync_binlog=1        //当执行事务时,将产生的数据和DDL立即同步到binlog中
  innodb_flush_logs_at_trx_commit=1 
    
#service mysqld restart
     登录数据库并添加用户,此用户具有replication client 和replication slave 的权限
        mysql>grant replication client,replication slave on *.* to repl@'172.16.%.%' identifided by '123456';
        mysql>show grants for  repl@'172.16.%.%';       
        mysql> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000001 | 11404543 |              |                  |
+------------------+----------+--------------+------------------+
   
    从服务器中的配置 (172.16.21.2)
      vim my.cnf
       [mysqld]
         server-id=11
         skip_slave_start=1
         read_only=1
        
         #bin-log=mysql-bin
         relay-log=relay-bin
         relay-log-index=relay-bin.index
       登录数据库,将主服务器指向172.16.21.1 用户是repl 密码为123456  与上面的主服务器设置相对应
          mysql>change master to master_user='repl',master_host='172.16.21.1',master_bin_log='mysql-bin.000001';
          mysql>start slave;
          mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 172.16.21.1
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 11404543
               Relay_Log_File: relay-bin.000002
                Relay_Log_Pos: 11404689
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB:
          Replicate_Ignore_DB:
           Replicate_Do_Table:
       Replicate_Ignore_Table:
      Replicate_Wild_Do_Table:
  Replicate_Wild_Ignore_Table:
                   Last_Errno: 0
                   Last_Error:
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 11404543
              Relay_Log_Space: 11404839
              Until_Condition: None
               Until_Log_File:
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File:
           Master_SSL_CA_Path:
              Master_SSL_Cert:
            Master_SSL_Cipher:
               Master_SSL_Key:
        Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error:
               Last_SQL_Errno: 0
               Last_SQL_Error:
  Replicate_Ignore_Server_Ids:
             Master_Server_Id: 1
1 row in set (0.00 sec)
         
          如果主从服务器都是第一次搭建,且没有数据存入时,在开启slave出错时的解决方法:
            在主服务器中的数据库执行
             mysql>flush master;    //滚动二进制日志
            在从服务器中执行
             mysql>flush slave;    //滚动中继日志
         
二、主主复制:
 
主1:(172.16.21.2)
   如果是第一次开启:
       开启二进制日志 和中继日志功能
         [mysqld]
             server-id=1
             log-bin=mysql-bin
             relay-log=relay-bin
             relay-log-index=realy-bin.index
        >grant replication client,replication slave on *.* to repl@'172.16.%.%'
        >change MASTER TO MASTER_HOST='172.16.21.1',MASTER_USER='repl',MASTER_PASSWORD='123456'
              MASTER_LOG_FILE='mysql-bin.000003', MASTER_LOG_POS=811      //这里的MASTER_LOG_FILE 和MASTER_LOG_POS是主服务器的
                                                                       show master status;信息
         >start slave;
         >show slave status;
                
 主2:(172.16.21.1)
   如果是第一次开启:
       开启二进制日志 和中继日志功能
         [mysqld]
             server-id=1
             log-bin=mysql-bin
             relay-log=relay-bin
             relay-log-index=relay-bin.index
        >grant replication client,replication slave on *.* to repl@'172.16.%.%'
        >change MASTER TO MASTER_HOST='172.16.21.2',MASTER_USER='repl',MASTER_PASSWORD='123456'
              MASTER_LOG_FILE='mysql-bin.000003', MASTER_LOG_POS=811      //这里的MASTER_LOG_FILE 和MASTER_LOG_POS是主服务器的
                                                                       show master status;信息
         >start slave;
         >show slave status;
 
三、设置半同步:
 mysql的主从复制是基于异步实现的,可以通过在master端安装  semisync_master.so 插件
   在slave端安装 semisync_slave.so 插件来实现半同步,这里所谓的半同步是当一主多从时,
   主给一个从实现同步,当此过程超过时间限定后(通过rpl_semi_sync_master_timeout 来设置),
   则降级为异步。
  设置方法:
    主服务器(172.16.21.1)
       mysql> INSTALL PLUGIN rpl_semi_sync_master SONAME 'semisync_master.so'; 
       mysql> SET GLOBAL rpl_semi_sync_master_enabled = 1; 
       mysql> SET GLOBAL rpl_semi_sync_master_timeout = 1000; 
     从服务器(172.16.21.2)
         mysql> INSTALL PLUGIN rpl_semi_sync_slave SONAME 'semisync_slave.so'; 
         mysql> SET GLOBAL rpl_semi_sync_slave_enabled = 1; 
         mysql> STOP SLAVE IO_THREAD; START SLAVE IO_THREAD; 
         // 重启从服务器的IO线程 以实现插件功能
         
查看从服务器是否开启semi_sync
 mysql> show global status like 'rpl_semi%';
+----------------------------+-------+
| Variable_name              | Value |
+----------------------------+-------+
| Rpl_semi_sync_slave_status | ON    |
+----------------------------+-------+
1 row in set (0.04 sec)
 
 查看主服务器是否开启semi_sync
  mysql> show global status like 'rpl_semi%';
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients               | 1     |
| Rpl_semi_sync_master_net_avg_wait_time     | 0     |
| Rpl_semi_sync_master_net_wait_time         | 0     |
| Rpl_semi_sync_master_net_waits             | 0     |
| Rpl_semi_sync_master_no_times              | 0     |
| Rpl_semi_sync_master_no_tx                 | 0     |
| Rpl_semi_sync_master_status                | ON    |
| Rpl_semi_sync_master_timefunc_failures     | 0     |
| Rpl_semi_sync_master_tx_avg_wait_time      | 0     |
| Rpl_semi_sync_master_tx_wait_time          | 0     |
| Rpl_semi_sync_master_tx_waits              | 0     |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |
| Rpl_semi_sync_master_wait_sessions         | 0     |
| Rpl_semi_sync_master_yes_tx                | 0     |
+--------------------------------------------+-------+
14 rows in set (0.01 sec)
         
    上述命令中的set后的参数可以写在各自服务器中的my.cnf  [mysqld] 下,以实现永久生效
       取消加载插件 可使用命令;
    mysql> UNINSTALL PLUGIN rpl_semi_sync_master;
  
四、基于ssl的主从复制
    主从复制是数据在网络中是明文传输 所以设置主从服务基于ssl的复制就显得必要  这里有官方文档,也可使用下列相关配置
  官方文档地址: http://dev.mysql.com/doc/refman/5.1/en/replication-solutions-ssl.html 
   
    以下配置需要在主从复制建立的基础上进行,所以只添加ssl的配置选项,其他选项可参照主从复制配置
     首先分别为主从申请证书(证书申请相关步骤略过)
     master(172.16.21.1):
        CA证书:/etc/pki/CA/cacert.pem
        私钥:/usr/local/mysql/ssl/master.key
        服务器证书:/usr/local/mysql/ssl/master.crt
       
        vim my.cnf   
        [mysqld]
ssl-ca=/etc/pki/CA/cacert.pem
ssl-cert=/usr/local/mysql/ssl/master.crt
ssl-key=/usr/local/mysql/ssl/master.key
#serivce mysqld restart
 
     slave (172.16.21.2):
        CA证书:/etc/pki/CA/cacert.pem
        私钥:/usr/local/mysql/ssl/slave.key
        服务器证书:/usr/local/mysql/ssl/slave.crt
        vim my.cnf
        [client]
        ssl-ca=/etc/pki/CA/cacert.pem
        ssl-cert=/usr/local/mysql/ssl/slave.crt
        ssl-key=/usr/local/mysql/ssl/slave.key
 
service mysqld restart  //因为要更改master的相关选项,所以重启mysql不需要立即启动slave,可以在配置文件中定义skip_slave_start=1来实现之
 
登录从服务器mysql 更改master的相关选项,以实现ssl功能
mysql> CHANGE MASTER TO
    -> MASTER_HOST='172.16.21.1',
    -> MASTER_USER='repl',
    -> MASTER_PASSWORD='123456',
    -> MASTER_SSL=1,
    -> MASTER_SSL_CA = '/etc/pki/CA/cacert.pem',
    -> MASTER_SSL_CAPATH = '/etc/pki/CA',
    -> MASTER_SSL_CERT = '/usr/local/mysql/ssl/master.crt',
    -> MASTER_SSL_KEY = '/usr/local/mysql/ssl/master.key';
mysql>start slave;
mysql>show slave status;
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
           Master_SSL_Allowed: Yes
           Master_SSL_CA_File: /etc/pki/CA/cacert.pem
           Master_SSL_CA_Path: /etc/pki/CA
              Master_SSL_Cert: /usr/local/mysql/ssl/slave.crt
            Master_SSL_Cipher:
               Master_SSL_Key: /usr/local/mysql/slave.key
              
至此基于ssl功能实现  

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