mysql数据库同步
1.1. Master 设置步骤
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配置 my.cnf 文件
确保主服务器主机上my.cnf文件的[mysqld]部分包括一个log-bin选项。该部分还应有一个server-id=Master_id选项
# vim /etc/mysql/my.cnf server-id = 1
log_bin = /var/log/mysql/mysql-bin.log
expire_logs_days = 10
max_binlog_size = 100M
binlog_do_db = test
binlog_ignore_db = mysqlbind-address默认是127.0.0.1你必须更改它,否则Slave将无法链接到 Master
#bind-address = 127.0.0.1
bind-address = 0.0.0.0重启服务器
neo@netkiller :~$ sudo /etc/init.d/mysql reload
* Reloading MySQL database server mysqld [ OK ]建议使用reload,如果不起作用再用restart
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登录slave服务器,测试主库3306工作情况,如果看到下面相关信息表示工作正常。
# telnet 192.168.1.246 3306
Trying 192.168.1.246...
Connected to 192.168.1.246.
Escape character is '^]'.
I
5.1.61-0ubuntu0.11.10.1-log1W<gs/*'#}p<u[J=5//: -
创建账户并授予REPLICATION SLAVE权限
mysql> GRANT REPLICATION SLAVE ON *.* TO 'replication'@'%.mydomain.com' IDENTIFIED BY 'slavepass';
mysql> FLUSH PRIVILEGES;GRANT REPLICATION SLAVE, REPLICATION CLIENT ON *.* TO replication@'192.168.245.131' IDENTIFIED BY 'slavepass'
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锁表禁止写入新数据
mysql> FLUSH TABLES WITH READ LOCK;
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查看Master 工作状态
mysql> SHOW MASTER STATUS;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000002 | 106 | test | mysql |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)如果显示下面内容表示,配置不正确
mysql> SHOW MASTER STATUS;
Empty set (0.02 sec)取得快照并记录日志名和偏移量后,可以在主服务器上重新启用写活动
mysql> UNLOCK TABLES;
5.1.2. Slave
过程 1.2. Slave 设置步骤
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配置my.cnf
从服务器的ID必须与主服务器的ID不相同,如果设置多个从服务器,每个从服务器必须有一个唯一的server-id值,必须与主服务器的以及其它从服务器的不相同。
# vim /etc/mysql/my.cnf [mysqld]
server-id = 2 # service mysql restart
mysql start/running, process 22893-
指定 master 相关参数
在从服务器上执行下面的语句,用你的系统的实际值替换选项值
mysql> CHANGE MASTER TO
-> MASTER_HOST='master_host_name',
-> MASTER_USER='replication_user_name',
-> MASTER_PASSWORD='replication_password',
-> MASTER_LOG_FILE='recorded_log_file_name',
-> MASTER_LOG_POS=recorded_log_position;CHANGE MASTER TO MASTER_HOST='192.168.245.129', MASTER_USER='replication', MASTER_PASSWORD='slavepass';
mysql> CHANGE MASTER TO MASTER_HOST='192.168.245.129', MASTER_USER='repl', MASTER_PASSWORD='slavepass';
Query OK, 0 rows affected (0.14 sec) -
启动从服务器线程
mysql> START SLAVE;
Query OK, 0 rows affected (0.00 sec) -
SLAVE STATUS
mysql> SHOW SLAVE STATUS\G
*************************** 1. row ***************************
Slave_IO_State: Connecting to master
Master_Host: 192.168.245.129
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File:
Read_Master_Log_Pos: 4
Relay_Log_File: mysqld-relay-bin.000002
Relay_Log_Pos: 98
Relay_Master_Log_File:
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: 0
Relay_Log_Space: 98
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
1 row in set (0.00 sec)
5.1.3. Testing
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登录 master
复制进程的信息
SHOW PROCESSLIST语句可以提供在主服务器上和从服务器上发生的关于复制的信息
mysql> SHOW PROCESSLIST\G
*************************** 1. row ***************************
Id: 62
User: replication
Host: ken-hx409.local:36465
db: NULL
Command: Binlog Dump
Time: 679
State: Has sent all binlog to slave; waiting for binlog to be updated
Info: NULL
*************************** 2. row ***************************
Id: 64
User: root
Host: localhost
db: NULL
Command: Query
Time: 0
State: NULL
Info: SHOW PROCESSLIST
2 rows in set (0.00 sec) -
登录从库,查看复制线程
mysql> SHOW PROCESSLIST\G
*************************** 1. row ***************************
Id: 273
User: root
Host: localhost
db: NULL
Command: Query
Time: 0
State: NULL
Info: SHOW PROCESSLIST
*************************** 2. row ***************************
Id: 276
User: system user
Host:
db: NULL
Command: Connect
Time: 2
State: Waiting for master to send event
Info: NULL
*************************** 3. row ***************************
Id: 277
User: system user
Host:
db: NULL
Command: Connect
Time: 2
State: Has read all relay log; waiting for the slave I/O thread to update it
Info: NULL
3 rows in set (0.00 sec)如果没有复制进程,请使用start slave;启动
mysql> SHOW PROCESSLIST\G
*************************** 1. row ***************************
Id: 273
User: root
Host: localhost
db: NULL
Command: Query
Time: 0
State: NULL
Info: SHOW PROCESSLIST
1 row in set (0.02 sec) mysql> start slave;
Query OK, 0 rows affected (0.00 sec) -
登录 master
mysql> insert into foo(id,data) values(2,'Hello world!!!');
Query OK, 1 row affected (0.00 sec) -
登录 slave
mysql> select * from foo;
在master服务器上插入一条记录,你可以立刻在slave服务器上看到变化。
5.1.4. 将现有数据库迁移到主从结构数据库
数据库已经存在的情况下怎么迁移
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Master 锁表禁止写入新数据
mysql> FLUSH TABLES WITH READ LOCK;
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Slave 停止复制进程
mysql> stop slave;
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备份Master数据库
mysqldump yourdb | gzip > yourdb.sql.gz
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恢复数据库
如果使用mysqldump备份主服务器的数据,将转储文件装载到从服务器
# zcat yourdb.sql.gz | mysql -u root -p yourdb
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启动 Slave 复制进程
mysql> start slave;
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解除 Master 表锁定
mysql> UNLOCK TABLES;
MyIASM引擎可以采用下面方法
备份数据库
# tar zcvf mysql-snapshot.tar.gz /var/lib/mysql/neo
复制给从数据库
scp mysql-snapshot.tar.gz neo@192.168.245.131:/tmp
snapshot 恢复
$ tar zxvf mysql-snapshot.tar.gz
$ cd /var/lib/mysql $ mv /tmp/var/lib/mysql/neo .
$ sudo chown mysql.mysql -R neo
重新启动Mysql
$ sudo /etc/init.d/mysql restart
有兴趣可以看看mysqlhotcopy
5.1.5. 主从复制安全问题
复制帐号权限
grant replication slave on *.* to 'replication'@'192.168.1.%' identified by '000000';
主库数据库操作帐号权限
grant DELETE, INSERT, SELECT, UPDATE ON your_user.* to yourdb@'your_host' identified by 'password' with grant option;
从库数据库操作帐号权限
grant SELECT ON your_user.* to yourdb@'your_host' identified by 'password' with grant option;
从库必须收回写操作
5.1.6. 主从不同步问题
执行下面语句
stop slave;
set global sql_slave_skip_counter =1 ;
start slave;
Seconds_Behind_Master 值从NULL变为大于等于0是表示已经同步
Seconds_Behind_Master: NULL
Seconds_Behind_Master: 8893
5.2. Master Master(主主)
5.2.1. Master A
my.cnf 文件加入下面的内容
cp /etc/mysql/my.cnf /etc/mysql/my.cnf.old
vim /etc/mysql/my.cnf [mysqld]
server-id = 1
log-bin=/data/mysql/binlog/binlog
binlog-do-db = test
binlog-ignore-db=mysql log-slave-updates
sync_binlog=1
auto_increment_offset=1
auto_increment_increment=2
replicate-do-db = test
replicate-ignore-db = mysql,information_schema
创建复制权限
grant replication slave on *.* to 'replication'@'192.168.1.%' identified by '000000';
flush privileges;
mysql>flush tables with read lock; mysql> show master status\G
*************************** 1. row ***************************
File: binlog.000007
Position: 107
Binlog_Do_DB: test
Binlog_Ignore_DB: mysql
1 row in set (0.00 sec)
5.2.2. Master B
创建复制权限
grant replication slave on *.* to 'replication'@'192.168.1.%' identified by '000000';
flush privileges;
my.cnf 文件加入下面的内容
[mysqld]
server-id = 2
log-bin = /data/mysql/binlog/binlog
replicate-do-db = test
replicate-ignore-db = mysql,information_schema binlog-do-db = test
binlog-ignore-db=mysql
log-slave-updates
sync_binlog=1
auto_increment_offset=2
auto_increment_increment=2
B 与 A 配置文件不同的两处。
server-id = 2
auto_increment_offset=2
mysql> show master status\G
*************************** 1. row ***************************
File: binlog.000005
Position: 107
Binlog_Do_DB: test
Binlog_Ignore_DB: mysql
1 row in set (0.00 sec)
5.2.3. 将Master A 数据库 同步到 Master B 两端数据库内容保持一致
Master A,首先锁表为只读状态
mysqldump --databases test > /tmp/test.sql
Master B 创建一个与Master A同名的空数据库,然后将备份文件恢复到数据库中
# mysql
mysql> CREATE DATABASE test;
mysql>\q # scp 192.168.1.1:/tmp/test.sql ./
# mysql -uroot -p test < /tmp/test.sql
5.2.4. Master A - B 同步两端数据库
master-A
mysql>change master to master_host='192.168.1.2', master_user='replication', master_password='000000', master_log_file='binlog.000005', master_log_pos=107;
master-B
mysql>change master to master_host='192.168.1.1', master_user='replication', master_password='000000', master_log_file='binlog.000007', master_log_pos=107;
5.2.5. Master A 数据库解除只读权限
Master A 解锁
mysql> UNLOCK TABLES;
5.2.6. 查看主主的工作状态
分别在Master A与B 上运行
mysql>show slave status\G; Slave_IO_Running: Yes
Slave_SQL_Running: Yes
5.3. 与复制有关的问题
5.3.1. expire-logs-days
缺省expire-logs-days为30天。这里设为7天,可根据自己情况调整。
[mysqld]
expire-logs-days = 7
5.3.2. Semisynchronous Replication
mysql> SHOW VARIABLES LIKE "have_dynamic_loading";
+----------------------+-------+
| Variable_name | Value |
+----------------------+-------+
| have_dynamic_loading | YES |
+----------------------+-------+
1 row in set (0.00 sec) mysql>
master > INSTALL PLUGIN rpl_semi_sync_master SONAME ‘libsemisync_master.so’;
slave-x > INSTALL PLUGIN rpl_semi_sync_slave SONAME ‘libsemisync_slave.so’;
master > SET GLOBAL rpl_semi_sync_master_enabled=1;
slave-x > SET GLOBAL rpl_semi_sync_slave_enabled=1;
CREATE USER 'replication'@'192.168.1.%' IDENTIFIED BY 'password';
GRANT ALL PRIVILEGES ON *.* TO 'replication'@'192.168.1.%' IDENTIFIED BY 'password' WITH GRANT OPTION MAX_QUERIES_PER_HOUR 0 MAX_CONNECTIONS_PER_HOUR 0 MAX_UPDATES_PER_HOUR 0 MAX_USER_CONNECTIONS 0 ;
master_heartbeat_period
STOP SLAVE;
CHANGE MASTER TO master_heartbeat_period= milliseconds;
START SLAVE;
mysql> CHANGE MASTER TO MASTER_HOST='xxx.xxx.xxx.xxx', MASTER_USER='root', MASTER_PASSWORD='password', MASTER_PORT=3306, MASTER_CONNECT_RETRY=10, MASTER_LOG_FILE='mysql-bin.000004', MASTER_LOG_POS=107;
跳过出问题的MySQL实例
CHANGE MASTER TO MASTER_HOST=xxx.xxx.xxx.xxx IGNORE_SERVER_IDS=y
编辑my.cnf加入
# On Master
[mysqld]
rpl_semi_sync_master_enabled=1
rpl_semi_sync_master_timeout=1000 # 1 second # On Slave
[mysqld]
rpl_semi_sync_slave_enabled=1