Mysql实现主从配置和多主多从配置
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2022-04-03 18:19:35
我们现在模拟的是主从(1台主机、一台从机)，其主从同步的原理，就是对bin-log二进制文件的同步，将这个文件的内容从主机同步到从机。一、配置文件的修改1、主机配置文件修改配置我们首先需要mysql主...
我们现在模拟的是主从(1台主机、一台从机)，其主从同步的原理，就是对bin-log二进制文件的同步，将这个文件的内容从主机同步到从机。
一、配置文件的修改
1、主机配置文件修改配置
我们首先需要mysql主机(192.168.254.130)的/etc/my.cnf配置文件，添加如下配置:
#主机唯一id server-id=1 #二进制日志 log-bin=mysql-bin #不需要同步的数据库 binlog-ignore-db=mysql binlog-ignore-db=information_schema #同步的数据库名称 binlog-do-db=mycat #二进制的格式 binlog_format=statement
我们看下目前整个my.cnf文件
[root@localhost desktop]# cat /etc/my.cnf [mysqld] datadir=/usr/local/mysql/data basedir=/usr/local/mysql socket=/usr/local/mysql/data/mysql.sock user=mysql # disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 server-id=1 log-bin=mysql-bin binlog-ignore-db=mysql binlog-ignore-db=information_schema binlog-do-db=mycat binlog_format=statement [mysqld_safe] log-error=/usr/local/mysql/data/mysqld.log pid-file=/usr/local/mysql/data/mysqld/mysqld.pid [root@localhost desktop]#
修改主机的配置文件后，我们需要通过命令重启下服务:
[root@localhost support-files]# ls magic mysqld_multi.server mysql-log-rotate mysql.server [root@localhost support-files]# pwd /usr/local/mysql/support-files [root@localhost support-files]# ./mysql.server restart
然后我们修改下从机(192.168.254.131)的配置文件。
2、从机的配置
从机的配置修改比较简单：
#从机机器唯一id server-id=2 #中继日志 relay-log=mysql-relay
同样修改配置后，我们重启下从机
二、mysql客户端命令操作
下面我们可以通过命令连接到mysql的命令端：
[root@localhost bin]# [root@localhost bin]# pwd /usr/local/mysql/bin [root@localhost bin]# ./mysql -uroot -p
1、主机操作
1）、创建同步用户
首先我们可以在主机创建一个专门用于主从同步用户，通过命令：
grant replication slave on *.* to 'slave'@'%' identified by '123456';
2）、查看同步文件状态
然后我们通过show master status;查看主机的同步内容状态：
mysql> show master status; +------------------+----------+--------------+--------------------------+-------------------+ | file | position | binlog_do_db | binlog_ignore_db | executed_gtid_set | +------------------+----------+--------------+--------------------------+-------------------+ | mysql-bin.000001 | 154 | mycat | mysql,information_schema | | +------------------+----------+--------------+--------------------------+-------------------+ 1 row in set (0.00 sec)
2、从机操作
1）、设置从机的主机
执行如下命令，这里设置了我们与主机建立同步的相关信息
change master to master_host='192.168.254.130', master_user='slave', master_password='123456', master_log_file='mysql-bin.000001', master_log_pos=430;
这里如果提示已经设置了主机配置，可以通过stop slave&reset master进行重置。
2）、启动同步
下面我们再通过start slave开启同步：
就可以看到：
mysql> show slave status\g
*************************** 1. row ***************************
slave_io_state: waiting for master to send event
master_host: 192.168.254.130
master_user: slave
master_port: 3306
connect_retry: 60
master_log_file: mysql-bin.000001
read_master_log_pos: 592
relay_log_file: mysql-relay.000002
relay_log_pos: 482
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: 592
relay_log_space: 685
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
master_uuid: 74397a99-accf-11eb-ae0d-000c2912d302
master_info_file: /usr/local/mysql/data/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:
executed_gtid_set:
auto_position: 0
replicate_rewrite_db:
channel_name:
master_tls_version:
1 row in set (0.00 sec)
mysql>
这里我们可以看到slave_io_running、slave_sql_running都为yes，则成功了，如果是下面这种：
*************************** 1. row ***************************
slave_io_state: connecting to master
master_host: 192.168.254.130
master_user: slave
master_port: 3306
connect_retry: 60
master_log_file: mysql-bin.000001
read_master_log_pos: 430
relay_log_file: mysql-relay.000001
relay_log_pos: 4
relay_master_log_file: mysql-bin.000001
slave_io_running: connecting
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: 430
relay_log_space: 154
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: null
master_ssl_verify_server_cert: no
last_io_errno: 1045
last_io_error: error connecting to master 'slave@192.168.254.130:3306' - retry-time: 60 retries: 1
last_sql_errno: 0
last_sql_error:
replicate_ignore_server_ids:
master_server_id: 0
master_uuid:
master_info_file: /usr/local/mysql/data/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: 210505 00:18:08
last_sql_error_timestamp:
master_ssl_crl:
master_ssl_crlpath:
retrieved_gtid_set:
executed_gtid_set:
auto_position: 0
replicate_rewrite_db:
channel_name:
master_tls_version:
1 row in set (0.00 sec)
我们可以看到last_io_error这里有错误，我们就可以去看下日志报的什么问题了，目前我这个是因为同步用户写错了才不能同步，按上面说的先停止同步重置，修改后同步命令，再操作一遍就可以了。
三、主从同步测试
1、主机创建库
我们先在主机创建我们前面设置的要同步的数据库mycat：
mysql> create database mycat; query ok, 1 row affected (0.00 sec) mysql> use mycat; database changed mysql> show databases; +--------------------+ | database | +--------------------+ | information_schema | | mycat | | mysql | | performance_schema | | sys | +--------------------+ 5 rows in set (0.00 sec) mysql>
2、从机查看库
然后我们就能在从机看到这个库了
mysql> show databases; +--------------------+ | database | +--------------------+ | information_schema | | mycat | | mysql | | performance_schema | | sys | +--------------------+ 5 rows in set (0.00 sec)
3、表数据的初始
下面我们进行表数据的测试
1）、主机
首先我们再主机建立表并插入数据
mysql> use mycat;
database changed
mysql>
mysql> create table `test1`(
-> id int auto_increment not null primary key,
-> name varchar(10) default null
-> );
query ok, 0 rows affected (0.03 sec)
mysql> insert into test1(`id`,`name`) value(1,"petty");
query ok, 1 row affected (0.16 sec)
mysql> select * from test1;
+----+-------+
| id | name |
+----+-------+
| 1 | petty |
+----+-------+
1 row in set (0.00 sec)
mysql>
2）、从机
下面我们在从机查看看有没有成功同步：
mysql> use mycat; reading table information for completion of table and column names you can turn off this feature to get a quicker startup with -a database changed mysql> show tables; +-----------------+ | tables_in_mycat | +-----------------+ | test1 | +-----------------+ 1 row in set (0.00 sec) mysql> select * from test1; +----+-------+ | id | name | +----+-------+ | 1 | petty | +----+-------+ 1 row in set (0.00 sec) mysql>
可以看到我们的主从配置已经成功了。
四、多主多从
我们还可以多主多从，例如我们一个主从序列是编号1位主机、编号2为从机，然后编号3为主机、编号4为从机，同时编号1主机与编号3主机相互为主从，这样就是其中主机一台有问题，整个mysql集群还是能正常工作。
由于目前只有3台机，只使用三台来写demo(一台windows，两台linux)。
1、编号1主机(192.168.254.30)
1）、修改配置
我们首先需要修改其原来的etc/my.cnf文件，添加：
# 作为从机也修改其bin-log日志 log-slave-updates #自增长的幅度 auto-increment-increment=2 #自增长的开始位置 auto-increment-offset=1
整个文件的信息
[root@localhost desktop]# cat /etc/my.cnf [mysqld] datadir=/usr/local/mysql/data basedir=/usr/local/mysql socket=/usr/local/mysql/data/mysql.sock user=mysql # disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 server-id=1 log-bin=mysql-bin binlog-ignore-db=mysql binlog-ignore-db=information_schema binlog-do-db=mycat binlog_format=statement log-slave-updates auto-increment-increment=2 auto-increment-offset=1 [mysqld_safe] log-error=/usr/local/mysql/data/mysqld.log pid-file=/usr/local/mysql/data/mysqld/mysqld.pid [root@localhost desktop]#
修改这个文件后我们需要重启机器
2、编号2从机（192.168.254.31）
这台原来已经配置其连接30机器了，所以这次不用修改
3、编号3主机(192.168.254.1)
1）、修改配置文件
由于这台机器是windows，所以我们需要修改其的my.ini文件，在其最后面添加
server-id=3 log-bin=mysql-bin binlog-ignore-db=mysql binlog-ignore-db=information_schema binlog-do-db=mycat binlog_format=statement log-slave-updates auto-increment-increment=2 auto-increment-offset=2
注意我们上面改了server-id，同时也改了其的增长开始点auto-increment-offset=2。同时再重启服务。
2）、创建同步用户
首先我们可以在主机创建一个专门用于主从同步用户，通过命令：
grant replication slave on *.* to 'slave'@'%' identified by '123456';
3）、查看状态
mysql> show master status; +------------------+----------+--------------+--------------------------+-------------------+ | file | position | binlog_do_db | binlog_ignore_db | executed_gtid_set | +------------------+----------+--------------+--------------------------+-------------------+ | mysql-bin.000001 | 154 | mycat | mysql,information_schema | | +------------------+----------+--------------+--------------------------+-------------------+ 1 row in set (0.00 sec) mysql>
4）、设置同步的状态
下面我们运行其连接的主机(30)信息
change master to master_host='192.168.254.130', master_user='slave', master_password='123456', master_log_file='mysql-bin.000001', master_log_pos=430;
5）、编号1主机同步(192.168.254.30)
我们需要设置其去同步编号3主机(192.168.254.1)，即我们前面查看的编号3的(master status)：
change master to master_host='192.168.254.1', master_user='slave', master_password='123456', master_log_file='mysql-bin.000001', master_log_pos=154;
然后我们在编号1主机执行同步start slave;，也在编号3主机执行同步start slave;。
4、测试查看
1）、可能的问题(可略过)
现在我们测试，然后分别查看这两台的master状态show master status;。
mysql> show slave status\g
*************************** 1. row ***************************
slave_io_state: waiting for master to send event
master_host: 192.168.254.1
master_user: slave
master_port: 3306
connect_retry: 60
master_log_file: mysql-bin.000001
read_master_log_pos: 154
relay_log_file: localhost-relay-bin.000002
relay_log_pos: 320
relay_master_log_file: mysql-bin.000001
slave_io_running: yes
slave_sql_running: yes
........
mysql> show slave status\g
*************************** 1. row ***************************
slave_io_state: waiting for master to send event
master_host: 192.168.254.130
master_user: slave
master_port: 3306
connect_retry: 60
master_log_file: mysql-bin.000002
read_master_log_pos: 462
relay_log_file: laptop-qr83qec0-relay-bin.000003
relay_log_pos: 675
relay_master_log_file: mysql-bin.000002
slave_io_running: yes
slave_sql_running: yes
replicate_do_db:
.........
可以看到它们的同步都是yes。这里可能有问题，我们需要自己解决，例如我在编号1机器修改配置，然后在查看其的状态，
mysql> show master status; +------------------+----------+--------------+--------------------------+-------------------+ | file | position | binlog_do_db | binlog_ignore_db | executed_gtid_set | +------------------+----------+--------------+--------------------------+-------------------+ | mysql-bin.000002 | 462 | mycat | mysql,information_schema | | +------------------+----------+--------------+--------------------------+-------------------+ 1 row in set (0.00 sec) mysql>
我如果以这个消息去让编号3机器同步编号1，就会报(因为我又运行了一条新的插入语句)，但建表语句是在日志mysql-bin.000001，而这里我因为重启了，其有有新的mysql-bin.000002，所以有修改回了原来编号2的同步信息。
mysql> show slave status\g
*************************** 1. row ***************************
slave_io_state: waiting for master to send event
master_host: 192.168.254.130
master_user: slave
master_port: 3306
connect_retry: 60
master_log_file: mysql-bin.000002
read_master_log_pos: 462
relay_log_file: laptop-qr83qec0-relay-bin.000002
relay_log_pos: 320
relay_master_log_file: mysql-bin.000002
slave_io_running: yes
slave_sql_running: no
replicate_do_db:
replicate_ignore_db:
replicate_do_table:
replicate_ignore_table:
replicate_wild_do_table:
replicate_wild_ignore_table:
last_errno: 1146
last_error: error 'table 'mycat.test1' doesn't exist' on query. default database: 'mycat'. query: 'insert into test1(`id`,`name`) value(2,"tom")'
2）、在编号3插入数据
下面我们再编号3插入数据，看编号1、2能不能看到
在编号3操作：
mysql> insert into test1(`id`,`name`) value(3,"kitt"); query ok, 1 row affected (0.01 sec) mysql> select * from test1; +----+-------+ | id | name | +----+-------+ | 1 | petty | | 2 | tom | | 3 | kitt | +----+-------+ 3 rows in set (0.00 sec) mysql>
在编号1查看
mysql> select * from test1; +----+-------+ | id | name | +----+-------+ | 1 | petty | | 2 | tom | | 3 | kitt | +----+-------+ 3 rows in set (0.00 sec) mysql>
在编号2查看
mysql> select * from test1; +----+-------+ | id | name | +----+-------+ | 1 | petty | | 2 | tom | | 3 | kitt | +----+-------+ 3 rows in set (0.00 sec) mysql>
可以看到目前我们已经同步成功了，在编号1中能查看到主机编号3的插入信息。
3）、编号1处理数据
下面我们在编号1操作查看
编号1：
mysql> insert into test1(`id`,`name`) value(4,"lisa"); query ok, 1 row affected (0.00 sec) mysql> select * from test1; +----+-------+ | id | name | +----+-------+ | 1 | petty | | 2 | tom | | 3 | kitt | | 4 | lisa | +----+-------+ 4 rows in set (0.00 sec) mysql>
编号3：
mysql> select * from test1; +----+-------+ | id | name | +----+-------+ | 1 | petty | | 2 | tom | | 3 | kitt | | 4 | lisa | +----+-------+ 4 rows in set (0.00 sec) mysql>
可以看到其是相互同步的。
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