【转载】MySQL数据库的主从配置(多主对一从)
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一、实验环境部署

主服务器 192.168.18.42 端口3306  ==》 从服务器 192.168.18.44 端口 3306  
主服务器 192.168.18.43 端口3306  ==》 从服务器 192.168.18.44 端口 3307

##数据库，已经安装mysql服务，安装部分略。从服务器上的多个mysql实例，请看另一篇帖子《用mysql_multi 实现一台机器跑多台mysql 》

二、部署服务器

1.在两台主服务器上赋予从机权限，有多台丛机，就执行多次（我们这里两台主库使用统一帐号密码）。

mysql> grant replication slave on *.* to 'backup'@'192.168.18.44' identified by '123456';
Query OK, 0 rows affected (0.00 sec)

2.在主服务器上配置my.cnf

vi /etc/my.cnf

server-id = 1
log-bin = mysql-bin  #保证binlog可读
read-only = 0  #主机，读写都可以
#binlog-do-db = test   #需要备份数据，多个写多行，不写全部都备份
binlog-ignore-db = mysql #不需要备份的数据库，多个写多行

编辑后重启数据库 # service mysqld restart

3.配置从库服务器的my.cnf

vi /etc/my.cnf

[mysqld_multi]
mysqld = /mysql/bin/mysqld_safe
mysqladmin = /mysql/bin/mysqladmin

[mysqld1]
port    = 3306
socket  = /tmp/mysql3306.sock
pid-file = /data/mysql/data1/mysql3306.pid
datadir = /data/mysql/data1
skip-name-resolve
log-bin = mysql-bin-3306
log_slave_updates
expire_logs_days = 7
log-error = /data/mysql/data1/mysql3306.err
log_slow_queries = mysql3306-slow.log
long_query_time = 3
query_cache_size = 64M
query_cache_limit = 2M
slave-net-timeout = 10
server-id = 2                     #server id 不要与主库的重复
master-host = 192.168.18.42        #对应主库的 ip地址
master-user = backup               # slave 帐号
master-password = 123456           # 密码
master-port = 3306                 #主库端口
replicate-ignore-db=mysql           #跳过不备份的库
master-info-file = master.1842.info
master-connect-retry = 10
relay-log = relay-bin-1842          #中继日志
relay-log-index = relay-bin-1842
relay-log-info-file = relay-log-1842.info
default-character-set=gbk
innodb_data_home_dir = /data/mysql/data1
innodb_data_file_path = ibdata1:50M:autoextend
innodb_log_group_home_dir = /data/mysql/data1
innodb_buffer_pool_size = 3072M
innodb_file_per_table
innodb_open_files = 800
#innodb_flush_method = O_DIRECT
innodb_flush_method = O_DSYNC
skip-locking
key_buffer = 32M
max_allowed_packet = 16M
table_cache = 1024
sort_buffer_size = 8M
net_buffer_length = 8M
read_buffer_size = 2M
read_rnd_buffer_size = 8M
myisam_sort_buffer_size = 32M
max_connections = 100
read_only
wait_timeout=288000
interactive_timeout=288000
log-bin-trust-function-creators=1
replicate-ignore-db = test
replicate-ignore-table = mysql.columns_priv
replicate-ignore-table = mysql.host
replicate-ignore-table = mysql.db
replicate-ignore-table = mysql.procs_priv
replicate-ignore-table = mysql.tables_priv
replicate-ignore-table = mysql.user



[mysqld2]
port    = 3307
socket  = /tmp/mysql3307.sock
pid-file = /data/mysql/data2/mysql3307.pid
datadir = /data/mysql/data2
skip-name-resolve
log-bin = mysql-bin-3307
log_slave_updates
expire_logs_days = 7
log-error = /data/mysql/data1/mysql3307.err
log_slow_queries = mysql3307-slow.log
long_query_time = 3
query_cache_size = 6