mysql的主从，主主，半同步

主配置文件
[mysqld]
datadir=/data/mydata
log-bin=/data/binlogs/master-bin
socket=/var/lib/mysql/mysql.sock
innodb_file_per_table=on
server-id=1
sync_binlog=on #在事务提交时，立即把bin-log缓存区中的事件立即刷写到磁盘到的二进制日志区上，保证从服务器尽早同步数据
innodb_flush_log_at_trx_commit=on #当使用innodb引擎，在事务提交时，把内存中跟事务相关的数据立即写到事务日志中
innodb_support_xa=on #innodb支持分布式事务
从配置文件
[mysqld]
datadir=/data/mydata
# log-bin=/data/binlogs/bin-log
socket=/var/lib/mysql/mysql.sock
innodb_file_per_table=on
relay-log=/data/binlogs/relay-bin
server-id=7
read_only=on
skip_slave_start=on #第1次启动START SLAVE后，重启从mysql后，默认slave自动启动,应该关闭自动启动

#在主节点授权具有复制权限用户
为了方便，我这里给的权限十分大，生产环境不建议这么搞。一般给予REPLICATION SLAVE,REPLICATION CLIENT
MariaDB [(none)]> GRANT ALL ON *.* to "test"@"10.0.0.%" identified by "test";
MariaDB [(none)]> flush privileges;
#在从服务器上连接到主
MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST='10.0.0.41',MASTER_USER='test',MASTER_PASSWORD='test';
MariaDB [(none)]> START SLAVE；
#上面的方式，是从数据库从0开始同步主的数据，很简单就没有贴实验
#下面是先做完全还原后再从事件某位置同步主数据
[root@centos7-4 ~]# mysqldump --all-databases --flush-logs --master-data=2 --lock-all-tables >all.sql
[root@centos7-4 ~]# less all.sql
-- CHANGE MASTER TO MASTER_LOG_FILE='master-bin.000004', MASTER_LOG_POS=245;
[root@centos7-4 ~]# scp all.sql 10.0.0.41:/root/
MariaDB [(none)]> create database helloit;
MariaDB [(none)]> use helloit;
MariaDB [helloit]> CREATE TABLE test (id int);
MariaDB [helloit]> INSERT INTO test VALUES (1),(2),(3);
MariaDB [helloit]> show tables;
+-------------------+
| Tables_in_helloit |
+-------------------+
| test              |
+-------------------+
1 row in set (0.00 sec)

MariaDB [helloit]> select * from test;
+------+
| id   |
+------+
|    1 |
|    2 |
|    3 |
+------+

MariaDB [helloit]> GRANT REPLICATION SLAVE,REPLICATION CLIENT ON *.* TO "test"@"10.0.0.88" IDENTIFIED  BY "test";

#在备节点上
#先导入完全备份的数据
MariaDB [(none)]> source /root/all.sql;

MariaDB [test]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| hellodb            |
| mysql              |
| performance_schema |
| test               |
+--------------------+
#并没有 helloit这个
#这时再实行主从同步
MariaDB [test]> CHANGE MASTER TO MASTER_HOST="10.0.0.41",MASTER_USER="test",MASTER_PASSWORD="test",MASTER_LOG_FILE="master-bin.000004",MASTER_LOG_POS=245;
#在从上启动sql和IO线程
MariaDB [test]> START SLAVE;
#验证实验结果
MariaDB [test]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| hellodb            |
| helloit            |
| mysql              |
| performance_schema |
| test               |
+--------------------+

MariaDB [test]> use helloit;
MariaDB [helloit]> select * from test;
+------+
| id   |
+------+
|    1 |
|    2 |
|    3 |
+------+
MariaDB [helloit]> show master status;
+-------------------+----------+--------------+------------------+
| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+-------------------+----------+--------------+------------------+
| master-bin.000004 |     1115 |              |                  |
+-------------------+----------+--------------+------------------+

#再次在主数据库插入数据
MariaDB [helloit]> INSERT INTO test VALUES (4),(5),(6);
Query OK, 3 rows affected (0.02 sec)
Records: 3  Duplicates: 0  Warnings: 0

MariaDB [helloit]> select * from test;
+------+
| id   |
+------+
|    1 |
|    2 |
|    3 |
|    4 |
|    5 |
|    6 |
+------+
#在从数据库上查看结果
MariaDB [helloit]> select * from test;
+------+
| id   |
+------+
|    1 |
|    2 |
|    3 |
|    4 |
|    5 |
|    6 |
+------+
6 rows in set (0.00 sec)
MariaDB [helloit]> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 10.0.0.41
Master_User: test
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: master-bin.000004
Read_Master_Log_Pos: 1115
Relay_Log_File: relay-bin.000002
Relay_Log_Pos: 1400
Relay_Master_Log_File: master-bin.000004
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: 1115
Relay_Log_Space: 1688
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

注意：
1、从服务器应该为只读模式，在配置文件里设置read_only=on，但是对于超级管理用户无效，需要从终端施加读锁，一直在后台运行：
MariaDB [(none)]> FLUSH TABLES WITH READ LOCK;
2、在主从节点分别设置sync_master_info=on、sync_relay_log=on、sync_relay_log_info=on会降低I/O性能

主主复制
配置步骤：
1、各个节点使用一个唯一的server_id
2、都启动binary log 和relay_log
3、创建拥有复制权限的用户帐号
4、各自定义自动增长键为奇数和偶数
5、均把对方指定为主节点，并启动复制线程
主配置文件
[mysqld]
datadir=/data/mydata
log-bin=/data/binlogs/master-bin
relay_log=/data/relogs/relay-bin
socket=/var/lib/mysql/mysql.sock
innodb_file_per_table=on
server-id=1
auto_increment_offset=1
auto_increment_increment=2
从配置文件
[mysqld]
datadir=/data/mydata
log-bin=/data/binlogs/bin-log
relay-log=/data/relogs/relay-bin
socket=/var/lib/mysql/mysql.sock
innodb_file_per_table=on
server-id=7
auto_increment_offset=2
auto_increment_increment=2

各自创建授权帐号
主1
MariaDB [(none)]> GRANT REPLICATION SLAVE,REPLICATION CLIENT ON *.* TO "test"@"10.0.0.88" IDENTIFIED  BY "test";
MariaDB [(none)]> flush privileges;
MariaDB [(none)]> show master status;
+-------------------+----------+--------------+------------------+
| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+-------------------+----------+--------------+------------------+
| master-bin.000001 |      671 |              |                  |
+-------------------+----------+--------------+------------------+
主2
MariaDB [(none)]> GRANT REPLICATION SLAVE,REPLICATION CLIENT ON *.* TO "test"@"10.0.0.41" IDENTIFIED  BY "test";
MariaDB [(none)]> flush privileges;
MariaDB [(none)]> show master status;
+----------------+----------+--------------+------------------+
| File           | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+----------------+----------+--------------+------------------+
| bin-log.000003 |      671 |              |                  |
+----------------+----------+--------------+------------------+
#在主1上连主2
MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST="10.0.0.88",MASTER_USER="test",MASTER_PASSWORD="test",MASTER_LOG_FILE="bin-log.000003",MASTER_LOG_POS=671;
#在主2上连主1
MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST="10.0.0.41",MASTER_USER="test",MASTER_PASSWORD="test",MASTER_LOG_FILE="master-bin.000001",MASTER_LOG_POS=671;
#分别启动从模式
start slave
#在主1上插入一些数据
MariaDB [(none)]> source /root/hellodb.sql
MariaDB [hellodb]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| hellodb            |
| mysql              |
| performance_schema |
| test               |
+--------------------+
5 rows in set (0.02 sec)
#在主2上查看是否同步
MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| hellodb            |
| mysql              |
| performance_schema |
| test               |
+--------------------+
5 rows in set (0.00 sec)
#在主2上创建一个数据库
MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| IT                 |
| hellodb            |
| mysql              |
| performance_schema |
| test               |
+--------------------+
6 rows in set (0.00 sec)
#在主1上查看
MariaDB [hellodb]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| IT                 |
| hellodb            |
| mysql              |
| performance_schema |
| test               |
+--------------------+
6 rows in set (0.02 sec)
已经双主同步
#主1上的二进制日志和中继日志
[root@centos7-4 data]# ls /data/binlogs/
master-bin.000001  master-bin.index
[root@centos7-4 data]# ls binlogs/
master-bin.000001  master-bin.index
[root@centos7-4 data]# ls relogs/
relay-bin.000001  relay-bin.000002  relay-bin.index
#主2上的二进制日志和中继日志
[root@mariadb data]# ls binlogs/
bin-log.000001  bin-log.000002  bin-log.000003  bin-log.index
[root@mariadb data]# ls relogs/
relay-bin.000001  relay-bin.000002  relay-bin.index

半同步
#主配置文件
[mysqld]
datadir=/data/mydata
log-bin=/data/binlogs/master-bin
socket=/var/lib/mysql/mysql.sock
innodb_file_per_table=on
server-id=1
#从配置文件
[mysqld]
datadir=/data/mydata
#log-bin=/data/binlogs/bin-log
relay-log=/data/relogs/relay-bin
socket=/var/lib/mysql/mysql.sock
innodb_file_per_table=on
server-id=7

#主上创建具有复制权限的帐号
MariaDB [(none)]> GRANT REPLICATION SLAVE,REPLICATION CLIENT ON *.* TO "test"@"10.0.0.88" IDENTIFIED  BY "test";
#在从上连接主数据库
MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST="10.0.0.41",MASTER_USER="test",MASTER_PASSWORD="test",MASTER_LOG_FILE="master-bin.000003",MASTER_LOG_POS=413;
MariaDB [(none)]> start slave;
#检查主从能同步后，关闭主从状态，加入半同步插件
MariaDB [(none)]> stop slave;
#在主节点上安装主的半同步插件
MariaDB [(none)]> INSTALL PLUGIN rpl_semi_sync_master SONAME 'semisync_master.so';
MariaDB [(none)]> SET GLOBAL rpl_semi_sync_master_enabled=1;
MariaDB [(none)]> show global variables like "%semi%";
+------------------------------------+-------+
| Variable_name                      | Value |
+------------------------------------+-------+
| rpl_semi_sync_master_enabled       | ON    |
| rpl_semi_sync_master_timeout       | 10000 |
| rpl_semi_sync_master_trace_level   | 32    |
| rpl_semi_sync_master_wait_no_slave | ON    |
+------------------------------------+-------+

#在从节点上安装从的半同步插件
MariaDB [(none)]> INSTALL PLUGIN rpl_semi_sync_slave SONAME 'semisync_slave.so';
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> SET GLOBAL rpl_semi_sync_slave_enabled=1;
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> show global variables like "%semi%";
+---------------------------------+-------+
| Variable_name                   | Value |
+---------------------------------+-------+
| rpl_semi_sync_slave_enabled     | ON    |
| rpl_semi_sync_slave_trace_level | 32    |
+---------------------------------+-------+
2 rows in set (0.00 sec)
MariaDB [(none)]> start slave;
#在主上查看是否有从节点加入
MariaDB [(none)]> SHOW GLOBAL STATUS LIKE '%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     |
+--------------------------------------------+-------+
#已经有一个备用节点加入
#在主上创建新数据，测试效果
MariaDB [(none)]> CREATE DATABASE MBA;
MariaDB [(none)]> SHOW GLOBAL STATUS LIKE '%semi%';
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients               | 1     |
| Rpl_semi_sync_master_net_avg_wait_time     | 17434 |
| Rpl_semi_sync_master_net_wait_time         | 17434 |
| Rpl_semi_sync_master_net_waits             | 1     |
| 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      | 18407 |
| Rpl_semi_sync_master_tx_wait_time          | 18407 |
| Rpl_semi_sync_master_tx_waits              | 1     |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |
| Rpl_semi_sync_master_wait_sessions         | 0     |
| Rpl_semi_sync_master_yes_tx                | 1     |
+--------------------------------------------+-------+
#完成半同步过程需要1.8s左右。

复制过滤器
让从节点仅复制指定数据库，或指定数据库的指定表
有2种方式：
1、主服务器仅向二进制日志中记录与特定数据库（特定表）相关的事件,不建议使用，因为无法实现时间还原
2、从服务器SQL_THREAD在replay中继日志中的事件时，仅读取与特定数据库（特定表）相关的事件并应用于本地
在从服务器配置参数过滤，只复制MBA之个库
从数据库配置文件
[mysqld]
datadir=/data/mydata
#log-bin=/data/binlogs/bin-log
relay-log=/data/relogs/relay-bin
socket=/var/lib/mysql/mysql.sock
innodb_file_per_table=on
server-id=7
replicate_do_db=MBA #只允许复制MBA
注：可用参数
replicate_do_db= #白名单，只复制某个数据库
replicate_ignore_db= #黑名单
replicate_do_table= #表的白名单
replicate_ignore_table= #表的黑名单
replicate_wild_do_table= #表的通配表达，白名单
replicate_wild_ignore_table=

在主上插入数据
MariaDB [MBA]> CREATE TABLE hello (id int);
MariaDB [MBA]> INSERT INTO hello VALUES (1),(2),(3);
Query OK, 3 rows affected (0.02 sec)
Records: 3  Duplicates: 0  Warnings: 0

MariaDB [MBA]> select * from hello;
+------+
| id   |
+------+
|    1 |
|    2 |
|    3 |
+------+
在从上查看
MariaDB [MBA]> show tables;
+---------------+
| Tables_in_MBA |
+---------------+
| hello         |
+---------------+
1 row in set (0.00 sec)

MariaDB [MBA]> select * from hello;
+------+
| id   |
+------+
|    1 |
|    2 |
|    3 |
+------+
在主上插入其他库数据
MariaDB [MBA]> create database it;
Query OK, 1 row affected (0.00 sec)

MariaDB [MBA]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| MBA                |
| it                 |
| mysql              |
| performance_schema |
| test               |
+--------------------+
在从数据库上查看
MariaDB [MBA]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| MBA                |
| mysql              |
| performance_schema |
| test               |
+--------------------+
并没有it这个新创建的数据库