前言：
Mysql内建的复制功能是构建大型，高性能应用程序的基础。由于目前mysql的高可用性架构MMM和MHA均建立在复制的基础之上，本文就mysql主从复制进行实战描述，希望对读者提供帮助。
服务器规划：
主库：192.168.2.153
备库：192.168.2.154
mysql版本使用5.6.26脚本编译安装，并指定数据目录。
主从复制：
1.创建复制账号：
主库：
mysql> grant replication slave on *.* to repl@'192.168.2.%' identified by 'slave';
备库：
mysql> grant replication slave on *.* to repl@'192.168.2.%' identified by 'slave';
2.配置主库和备库：
修改my.cnf：
主库:
log_bin = mysql-bin
server_id= 153
备库：
log_bin = mysql-bin
server_id = 154
relay_log = /mvtech/mysql/log/mysql-relay-bin
log_slave_updates = 1
read_only = 1(不知道应用场合 暂时不添加)
3.启动复制
备库：
CHANGE MASTER TO MASTER_HOST='192.168.2.153',
MASTER_USER='repl',
MASTER_PASSWORD='slave',
MASTER_LOG_FILE='mysql-bin.000006',
MASTER_LOG_POS=0;
查看状态：show slave statusG
Slave_IO_Running: No
Slave_SQL_Running: No
启动备库
start slave
查看备库状态：show slave statusG
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
查看备库线程：
show processlistG
4.附主库和备库的my.cnf
主库：
[mysqld]
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
server-id = 153
skip-name-resolve
#skip-networking
back_log = 500
max_connections = 1000
max_connect_errors = 600
open_files_limit = 65535
table_open_cache = 384
max_allowed_packet = 4M
binlog_cache_size = 1M
max_heap_table_size = 8M
tmp_table_size = 16M
read_buffer_size = 2M
read_rnd_buffer_size = 16M
sort_buffer_size = 16M
join_buffer_size = 8M
thread_cache_size = 8
query_cache_size = 8M
query_cache_limit = 2M
key_buffer_size = 512M
ft_min_word_len = 4
transaction_isolation = REPEATABLE-READ
log_bin = mysql-bin
binlog_format = mixed
expire_logs_days = 30
log_error = /mvtech/mysql/log/mysql-error.log
slow_query_log = 1
long_query_time = 6
performance_schema = 0
explicit_defaults_for_timestamp
#lower_case_table_names = 1
skip-external-locking
default-storage-engine = InnoDB
innodb_file_per_table = 1
innodb_open_files = 500
innodb_buffer_pool_size = 64M
innodb_write_io_threads = 4
innodb_read_io_threads = 4
innodb_thread_concurrency = 8
innodb_purge_threads = 1
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 2M
innodb_log_file_size = 32M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 90
innodb_lock_wait_timeout = 120
bulk_insert_buffer_size = 8M
myisam_sort_buffer_size = 64M
myisam_max_sort_file_size = 10G
myisam_repair_threads = 1
interactive_timeout = 28800
wait_timeout = 28800
[mysqldump]
quick
max_allowed_packet = 16M
[myisamchk]
key_buffer_size = 8M
sort_buffer_size = 8M
read_buffer = 4M
write_buffer = 4M
备库：
[mysqld]
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
server-id = 154
skip-name-resolve
#skip-networking
back_log = 500
max_connections = 1000
max_connect_errors = 600
open_files_limit = 65535
table_open_cache = 384
max_allowed_packet = 4M
binlog_cache_size = 1M
max_heap_table_size = 8M
tmp_table_size = 16M
read_buffer_size = 2M
read_rnd_buffer_size = 16M
sort_buffer_size = 16M
join_buffer_size = 8M
thread_cache_size = 8
query_cache_size = 8M
query_cache_limit = 2M
key_buffer_size = 512M
ft_min_word_len = 4
transaction_isolation = REPEATABLE-READ
log_bin = mysql-bin
#slave add
relay_log = /mvtech/mysql/log/mysql-relay-bin
read_only = 1
log_slave_updates = 1
skip_slave_start
#slave add
binlog_format = mixed
expire_logs_days = 30
log_error = /mvtech/mysql/log/mysql-error.log
slow_query_log = 1
long_query_time = 6
performance_schema = 0
explicit_defaults_for_timestamp
#lower_case_table_names = 1
skip-external-locking
default-storage-engine = InnoDB
innodb_file_per_table = 1
innodb_open_files = 500
innodb_buffer_pool_size = 64M
innodb_write_io_threads = 4
innodb_read_io_threads = 4
innodb_thread_concurrency = 8
innodb_purge_threads = 1
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 2M
innodb_log_file_size = 32M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 90
innodb_lock_wait_timeout = 120
bulk_insert_buffer_size = 8M
myisam_sort_buffer_size = 64M
myisam_max_sort_file_size = 10G
myisam_repair_threads = 1
interactive_timeout = 28800
wait_timeout = 28800
[mysqldump]
quick
max_allowed_packet = 16M
[myisamchk]
key_buffer_size = 8M
sort_buffer_size = 8M
read_buffer = 4M
write_buffer = 4M
5.测试主从复制
在主库中创建新库，备库也有新库产生，往主库中导入大量数据时可通过show processlist G 查看执行操作，
6.mysql手工切换主从 20161208补充
#主库：
show slave hosts;
#备库：
#查看状态
mysql> show slave statusG
#关闭IO线程
mysql> stop slave IO_THREAD;
mysql> stop slave;
mysql> reset master;
mysql> show slave statusG
mysql> reset slave all;
#此时丛库已恢复至单机状态。
mysql> show binary logs;
#主库操作：
CHANGE MASTER TO MASTER_HOST='192.168.2.154',
MASTER_USER='repl',
MASTER_PASSWORD='slave',
MASTER_LOG_FILE='mysql-bin.000003',
MASTER_LOG_POS=120;
手动切换主从复制完毕。
注：mysql user库中有空的用户建议删掉，因为有时切换时会出现不使用密码即可登录的现象。将空用户删掉后重启mysql即可