Home > Database > Mysql Tutorial > body text

How to enable semi-synchronous replication in mysql 5.7

一个新手
Release: 2017-09-08 14:40:40
Original
3140 people have browsed it

1. Install related plug-ins

show plugins;  查看模块
help --uninstall; 查看卸载模块
Copy after login
master:
mysql> install plugin rpl_semi_sync_master soname 'semisync_master.so';  --安装 semisync_master.so插件 
Query OK, 0 rows affected (0.03 sec)
slave:
root@localhost [zw3306]>install plugin rpl_semi_sync_slave soname 'semisync_slave.so'; --安装 semisync_slave.so插件
Query OK, 0 rows affected (0.00 sec)
root@localhost [zw3306]>install plugin rpl_semi_sync_master soname 'semisync_master.so';
Query OK, 0 rows affected (0.00 sec)
Copy after login

2. Modified parameters:

set global rpl_semi_sync_master_enabled=1;
set global rpl_semi_sync_master_timeout=1000;
set global rpl_semi_sync_slave_enabled=1;
Copy after login

You can also write directly to the configuration file [mysqld]

master:
[mysqld]
rpl_semi_sync_master_enabled = 1 
rpl_semi_sync_master_timeout = 1000 # 1 second
slave:
[mysqld]
rpl_semi_sync_slave_enabled = 1
Copy after login

If you modify the parameters, you need to restart:

View the modified parameters

master: 
mysql> show global variables like '%rpl_semi%';
Copy after login
+-------------------------------------------+------------+
| Variable_name                             | Value      |
+-------------------------------------------+------------+
| rpl_semi_sync_master_enabled              | ON         |
| rpl_semi_sync_master_timeout              | 1000       |
| rpl_semi_sync_master_trace_level          | 32         |
| rpl_semi_sync_master_wait_for_slave_count | 1          |
| rpl_semi_sync_master_wait_no_slave        | ON         |
| rpl_semi_sync_master_wait_point           | AFTER_SYNC |
+-------------------------------------------+------------+
6 rows in set (0.00 sec)
Copy after login


##

slave:
root@localhost [(none)]>show global variables like '%rpl_semi%';
Copy after login
+-------------------------------------------+------------+
| Variable_name                             | Value      |
+-------------------------------------------+------------+
| rpl_semi_sync_master_enabled              | ON         |
| rpl_semi_sync_master_timeout              | 1000       |
| rpl_semi_sync_master_trace_level          | 32         |
| rpl_semi_sync_master_wait_for_slave_count | 1          |
| rpl_semi_sync_master_wait_no_slave        | ON         |
| rpl_semi_sync_master_wait_point           | AFTER_SYNC |
| rpl_semi_sync_slave_enabled               | ON         |
| rpl_semi_sync_slave_trace_level           | 32         |
+-------------------------------------------+------------+
8 rows in set (0.00 sec)
Copy after login
Copy after login


##If: If it turns out that the replication structure has already been built, it is very simple:

stop slave io_thread;
start slave io_thread;
Copy after login


3. Do synchronization

change master to master_host='192.168.26.233', master_port=3306, master_user='repl',master_password='repl', master_auto_position=1;
 
root@localhost [(none)]>start slave;
Query OK, 0 rows affected (0.01 sec)
root@localhost [(none)]>show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.26.233
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000002
          Read_Master_Log_Pos: 194
               Relay_Log_File: relay-bin.000004
                Relay_Log_Pos: 407
        Relay_Master_Log_File: mysql-bin.000002
             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: 194
              Relay_Log_Space: 861
              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: 3306100
                  Master_UUID: 7e354a2c-6f5f-11e6-997d-005056a36f08
             Master_Info_File: mysql.slave_master_info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 7e354a2c-6f5f-11e6-997d-005056a36f08:1-9
            Executed_Gtid_Set: 7e354a2c-6f5f-11e6-997d-005056a36f08:1-9,
ba0d5587-74d6-11e6-ab5c-005056a3f46e:1-2
                Auto_Position: 1
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)
ERROR: 
No query specified
Copy after login

5. Check whether the slave has data

root@localhost [zw3306]>show tables;
Copy after login

+------------------+
| Tables_in_zw3306 |
+------------------+
| t1               |
+------------------+
1 row in set (0.00 sec)
Copy after login



root@localhost [zw3306]>select * from t1;
Copy after login
+------+
| id   |
+------+
|    1 |
|    2 |
|    3 |
|    4 |
+------+
4 rows in set (0.00 sec)
Copy after login


6. How to confirm whether it is synchronous or semi-synchronous?

show global variables like '%semi%';
show global status like '%semi%';
Copy after login
master:
root@localhost [zw3306]>show global status like '%semi%';
Copy after login
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients               | 1     | 有多少个Semi-sync的备库
| Rpl_semi_sync_master_net_avg_wait_time     | 0     | 事务提交后,等待备库响应的平均时间
| Rpl_semi_sync_master_net_wait_time         | 0     | 等待网络响应的总次数
| Rpl_semi_sync_master_net_waits             | 7     | 总的网络等待时间
| Rpl_semi_sync_master_no_times              | 0     | 一共有几次从Semi-sync跌回普通状态
| Rpl_semi_sync_master_no_tx                 | 0     | 库未及时响应的事务数,如果这个值很大就有问题
| Rpl_semi_sync_master_status                | ON    | 主库上Semi-sync是否正常开启
| Rpl_semi_sync_master_timefunc_failures     | 0     | 时间函数未正常工作的次数
| Rpl_semi_sync_master_tx_avg_wait_time      | 410   | 开启Semi-sync,事务返回需要等待的平均时间
| Rpl_semi_sync_master_tx_wait_time          | 2876  | 事务等待备库响应的总时间
| Rpl_semi_sync_master_tx_waits              | 7     | 事务等待备库响应的总次数
| Rpl_semi_sync_master_wait_pos_backtraverse | 0     | 改变当前等待最小二进制日志的次数
| Rpl_semi_sync_master_wait_sessions         | 0     | 当前有几个线程在等备库响应
| Rpl_semi_sync_master_yes_tx                | 7     | Semi-sync模式下,成功的事务数
+--------------------------------------------+-------+
15 rows in set (0.00 sec)
Copy after login

root@localhost [zw3306]>show global variables like '%semi%';
Copy after login
+-------------------------------------------+------------+
| Variable_name                             | Value      |
+-------------------------------------------+------------+
| rpl_semi_sync_master_enabled              | ON         |
| rpl_semi_sync_master_timeout              | 1000       |
| rpl_semi_sync_master_trace_level          | 32         |
| rpl_semi_sync_master_wait_for_slave_count | 1          |
| rpl_semi_sync_master_wait_no_slave        | ON         |
| rpl_semi_sync_master_wait_point           | AFTER_SYNC |
| rpl_semi_sync_slave_enabled               | ON         |
| rpl_semi_sync_slave_trace_level           | 32         |
+-------------------------------------------+------------+
8 rows in set (0.00 sec)
Copy after login
Copy after login

##Rpl_semi_sync_master_no_tx

If this value is very large, there will be a problemThere are also other reasons;

mysql> show global status like '%semi%';
Copy after login
+--------------------------------------------+-------+
| 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             | 17    |
| Rpl_semi_sync_master_no_times              | 1     |
| Rpl_semi_sync_master_no_tx                 | 10    | 不是用半同步复制的
| Rpl_semi_sync_master_status                | OFF   |
| Rpl_semi_sync_master_timefunc_failures     | 0     |
| Rpl_semi_sync_master_tx_avg_wait_time      | 410   |
| Rpl_semi_sync_master_tx_wait_time          | 2876  |
| Rpl_semi_sync_master_tx_waits              | 7     |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |
| Rpl_semi_sync_master_wait_sessions         | 0     |
| Rpl_semi_sync_master_yes_tx                | 7     |
+--------------------------------------------+-------+
14 rows in set (0.01 sec)
Copy after login

操作10个事物,可以发现都是  Rpl_semi_sync_master_no_tx 
master接收到N个slave的应答后,才commit事物,等待1s用户可以设置应道slave的数量。
rpl_semi_sync_master_wait_for_slave_count=1 默认是1 
set global rpl_semi_sync_master_wait_for_slave_count=2;
Copy after login
means how many semi-synchronous slaves;

The above is the detailed content of How to enable semi-synchronous replication in mysql 5.7. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template