常见问题排查
1.数据不一致：
SHOW SLAVE STATUS \G;
Last_Errno: 1062
Last_Error: Error 'Duplicate entry 'xxxn-66-77' for key1' on query. Default database: 'guild'. Query: 'insert into pynpcrecord setMapCode = 'xxxn', UpdateTime = '2015-08-07 00:00:32''解决方法：在从库上将重复的主键记录删除，再次重启主从
deletefrom xxxx where 主键=yyyy;
stopslave;start slave;解决方法：停掉主从同步，忽略一次错误，再开启同步：
stop slave;
set global sql_slave_skip_counter=1;startslave;主主架构方案
1.思路：
1.两台mysql都可读写，互为主备，默认只使用一台（masterA）负责数据的写入，另一台（masterB）备用；
2.masterA是masterB的主库，masterB又是masterA的主库，它们互为主从；
3.两台主库之间做高可用,可以采用keepalived等方案（使用VIP对外提供服务）；
4.所有提供服务的从服务器与masterB进行主从同步（双主多从）;
5.建议采用高可用策略的时候，masterA或masterB均不因宕机恢复后而抢占VIP（非抢占模式）；2.操作：修改my.cnf
修改A的
[client]
port = 3306
socket = /tmp/mysql.sock
[mysqld]
basedir = /usr/local/mysql
port = 3306
socket = /tmp/mysql.sock
datadir = /usr/local/mysql/data
pid-file = /usr/local/mysql/data/mysql.pid
log-error = /usr/local/mysql/data/mysql.err
server-id = 1
auto_increment_offset = 1
auto_increment_increment = 2 #奇数ID
log-bin = mysql-bin #打开二进制功能,MASTER主服务器必须打开此项
binlog-format=ROW
binlog-row-p_w_picpath=minimal
log-slave-updates=true
gtid-mode=on
enforce-gtid-consistency=true
master-info-repository=TABLE
relay-log-info-repository=TABLE
sync-master-info=1
slave-parallel-workers=0
sync_binlog=0
binlog-checksum=CRC32
master-verify-checksum=1
slave-sql-verify-checksum=1
binlog-rows-query-log_events=1
#expire_logs_days=5
max_binlog_size=1024M #binlog单文件最大值
replicate-ignore-db = mysql #忽略不同步主从的数据库
replicate-ignore-db = information_schema
replicate-ignore-db = performance_schema
replicate-ignore-db = test
replicate-ignore-db = zabbix
max_connections = 3000
max_connect_errors = 30
skip-character-set-client-handshake #忽略应用程序想要设置的其他字符集
init-connect='SET NAMES utf8' #连接时执行的SQL
character-set-server=utf8 #服务端默认字符集
wait_timeout=1800 #请求的最大连接时间
interactive_timeout=1800 #和上一参数同时修改才会生效
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES #sql模式
max_allowed_packet = 10M
bulk_insert_buffer_size = 8M
query_cache_type = 1
query_cache_size = 128M
query_cache_limit = 4M
key_buffer_size = 256M
read_buffer_size = 16K
skip-name-resolve
slow_query_log=1
long_query_time = 6
slow_query_log_file=slow-query.log
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 16M
[mysql]
no-auto-rehash
[myisamchk]
key_buffer_size = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
[mysqldump]
quick
max_allowed_packet = 16M
[mysqld_safe]修改B的
[client]
port = 3306
socket = /tmp/mysql.sock
[mysqld]
basedir = /usr/local/mysql
port = 3306
socket = /tmp/mysql.sock
datadir = /usr/local/mysql/data
pid-file = /usr/local/mysql/data/mysql.pid
log-error = /usr/local/mysql/data/mysql.err
server-id = 2
auto_increment_offset = 2
auto_increment_increment = 2 #偶数ID
log-bin = mysql-bin #打开二进制功能,MASTER主服务器必须打开此项
binlog-format=ROW
binlog-row-p_w_picpath=minimal
log-slave-updates=true
gtid-mode=on
enforce-gtid-consistency=true
master-info-repository=TABLE
relay-log-info-repository=TABLE
sync-master-info=1
slave-parallel-workers=0
sync_binlog=0
binlog-checksum=CRC32
master-verify-checksum=1
slave-sql-verify-checksum=1
binlog-rows-query-log_events=1
#expire_logs_days=5
max_binlog_size=1024M #binlog单文件最大值
replicate-ignore-db = mysql #忽略不同步主从的数据库
replicate-ignore-db = information_schema
replicate-ignore-db = performance_schema
replicate-ignore-db = test
replicate-ignore-db = zabbix
max_connections = 3000
max_connect_errors = 30
skip-character-set-client-handshake #忽略应用程序想要设置的其他字符集
init-connect='SET NAMES utf8' #连接时执行的SQL
character-set-server=utf8 #服务端默认字符集
wait_timeout=1800 #请求的最大连接时间
interactive_timeout=1800 #和上一参数同时修改才会生效
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES #sql模式
max_allowed_packet = 10M
bulk_insert_buffer_size = 8M
query_cache_type = 1
query_cache_size = 128M
query_cache_limit = 4M
key_buffer_size = 256M
read_buffer_size = 16K
skip-name-resolve
slow_query_log=1
long_query_time = 6
slow_query_log_file=slow-query.log
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 16M
[mysql]
no-auto-rehash
[myisamchk]
key_buffer_size = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
[mysqldump]
quick
max_allowed_packet = 16M
[mysqld_safe]3.初始化：
cd /usr/local/mysql
scripts/mysql_install_db --user=mysql4.A 上面：
mysql> grant replication slave on *.* to 'repl'@'192.168.10.12' identified by '123456';
mysql> flush privileges;B上面：
mysql> grant replication slave on *.* to 'repl'@'192.168.10.11' identified by '123456';
mysql> flush privileges;5.配置同步信息：
A上面
mysql> change master to master_host='192.168.10.12',master_port=3306,master_user='repl',master_password='123456',master_log_file='mysql-bin.000003',master_log_pos=437;
mysql> start slave;
mysql> show slave status\G;B上面
mysql> change master to master_host='192.168.10.11',master_port=3306,master_user='repl',master_password='123456',master_log_file='mysql-bin.000003',master_log_pos=120;
start slave;
mysql> show slave status\G;完成
一主多从
主要配置：
1.修改master上的配置文件my.cnf。
在[mysqld]下添加如下字段：
server-id = 1
log-bin=mysql-bin
binlog-do-db=YYY //需要同步的数据库
binlog-ignore-db=mysql //被忽略的数据库
binlog-ignore-db=information-schema //被忽略的数据库在master上为slave添加一个同步账号
mysql> grant replication slave on *.* to 'affairlog'@'192.168.2.182' identified by 'pwd123';
//在slave1上登陆成功
mysql> grant replication slave on *.* to 'affairlog'@'192.168.2.111' identified by 'pwd123';
//在slave2上登陆成功保存后，重启master的mysql服务：
service mysql restart;用show master status命令查看日志情况
mysql> show master status\G;*************************** 1. row ***************************
File: mysql-bin.000087
Position: 106
Binlog_Do_DB: YYY
Binlog_Ignore_DB: mysql,information-schema
1 row in set (0.00 sec)
2.修改slave1上的配置文件my.cnf。
在[mysqld]下添加如下字段
[root@mysql182 ~]# vi /etc/my.cnf
server-id=182
master-host=192.168.3.101
master-user= affairlog
master-password=pwd123
master-port=3306
master-connect-retry=60
replicate-do-db=YYY //同步的数据库
replicate-ignore-db=mysql //被忽略的数据库
replicate-ignore-db=information-schema //被忽略的数据库保存后，重启slave的mysql服务：
service mysql restart;修改slave2上的配置文件my.cnf，和上面类似，只是把server-id改下，为了方便，我都用了相应的ip某位，
so，slave2上我设置的server-id是111。
在进入两个slave机中的mysql。
mysql>start slave;
mysql>show slave status\G;*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.3.101
Master_User: affairlog
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000087
Read_Master_Log_Pos: 106
Relay_Log_File: vm111-relay-bin.000002
Relay_Log_Pos: 251
Relay_Master_Log_File: mysql-bin.000087
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB: YYY
Replicate_Ignore_DB: mysql,information-schema
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: 106
Relay_Log_Space: 406
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:
1 row in set (0.00 sec)如果两个slave中的Slave_IO_Running、Slave_SQL_Running状态均为Yes则表明设置成功。