GTID是5.6时加入的，在5.7中被进一步完善，生产环境建议在5.7版本中使用.
GTID全称为Global Transaction Identifiers,全局事务标识符.
GTID的复制完全是基于事务的,每一个事务对应一个GTID.因此事务执行具有唯一ID,
主从复制时，无需再指定POS位置,只要对比ID有没被执行过,并且每个ID仅执行一次.
GTID复制限制:
不支持涉及非事务存储引擎的更新
不支持CREATE TABLE … SELECT语句
不支持针对临时表的操作: CREATE TEMPORARY TABLE和DROP TEMPORARY TABLE
配置tips
notice:主从都需要开启gtid_mode模式.
使用GITD复制模式官方建议使用row复制模式,具有最高性能.
一主多从模式下更能体现出多线程的性能；
MySQL5.7.x编译安装方法，参考https://www.aliang.org/MySQL/Centos7-3-install-MySQL5-7-17.html
Master my.cnf配置片段
[mysqld]
server-id = 1 #服务器id
gtid_mode = on #开启gtid模式
log-bin = /data/mysql/binlog/master-binlog #开启binlog
enforce_gtid_consistency = 1 #强制gtid一致性，开启后对于特定create table不被支持
log_slave_update = 1 #开启从库写入binlog
binlog_format = row #binlog开启row模式
relay_log_recovery = 1 #开启中继日志完整性（当slave从库宕机后，假如relay-log损坏了，导致一部分中继日志没有处理，则自动放弃所有未执行的relay-log，并且重新从master上获取日志，这样就保证了relay-log的完整性。）
sync-binlog = 1 #强制将binlog_cache写入磁盘，一致性要求不高的场景下设置为0可关闭，性能会大幅提速数倍
skip_slave_start = 1 #使slave在mysql启动时不启动复制进程，使用 start slave启动 Slave my.cnf配置片段
[mysqld]
server-id = 5 #服务器id
gtid_mode = on #开启gtid模式
log-bin = /data/mysql/binlog/slave-binlog #开启binlog
enforce_gtid_consistency = 1 #强制gtid一致性，开启后对于特定create table不被支持
log_slave_update = 1 #开启从库写入binlog
binlog_format = row #binlog开启row模式
relay_log_recovery = 1 #开启中继日志完整性（当slave从库宕机后，假如relay-log损坏了，导致一部分中继日志没有处理，则自动放弃所有未执行的relay-log，并且重新从master上获取日志，这样就保证了relay-log的完整性。）
sync-binlog = 1 #强制将binlog_cache写入磁盘，一致性要求不高的场景下设置为0可关闭，性能会大幅提速数倍
skip_slave_start = 1 #使slave在mysql启动时不启动复制进程，使用 start slave启动 基于GTID的复制
在Master上创建主从复制账号
grant replication slave on *.* to 'repl'@'192.168.121.%' identified by '12345678';
flush privileges;在Slave上执行
CHANGE MASTER TO MASTER_HOST='192.168.121.163',MASTER_PORT=3306,MASTER_USER='repl',MASTER_PASSWORD='12345678',MASTER_AUTO_POSITION=1;
START SLAVE;
SHOW SLAVE STATUS\G;查看主要参数
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
是否一致，然后可以测试主从同步了，master上创建库，查看slave是否同步·
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.121.163
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mybinlog.000002
Read_Master_Log_Pos: 620
Relay_Log_File: c69-164-relay-bin.000002
Relay_Log_Pos: 723
Relay_Master_Log_File: mybinlog.000002
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: 620
Relay_Log_Space: 932
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: 91a08937-7b0b-11e7-9575-52540061843d
Master_Info_File: mysql.slave_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: 91a08937-7b0b-11e7-9575-52540061843d:2-3
Executed_Gtid_Set: 415de1ab-7b4b-11e7-b279-525400f4de41:1,
91a08937-7b0b-11e7-9575-52540061843d:1-3
Auto_Position: 1
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
1 row in set (0.00 sec)
实例配置:
从库my.cnf:
[root@gpu010 rds04]$cat backup-my.cnf
# This MySQL options file was generated by innobackupex. # The MySQL server
[mysqld]
port = 3308
#innodb_checksum_algorithm=innodb
#innodb_log_checksum_algorithm=innodb
innodb_data_file_path=ibdata1:200M:autoextend
innodb_log_files_in_group=2
innodb_log_file_size=1572864000
#innodb_fast_checksum=false
#innodb_page_size=16384
#innodb_log_block_size=512
innodb_undo_directory=.
innodb_undo_tablespaces=0
server-id = 17
binlog-format = ROW
gtid-mode = ON
enforce-gtid-consistency = true
log-bin = hostname-bin
relay-log = hostname-relay-bin
relay_log_recovery = 1
sync-binlog = 0
skip_slave_start = 1
#rds_encrypt_data=false
#innodb_encrypt_algorithm=aes_128_ecb
xtrabackup_slave_info 文件内容
[root@gpu010 rds04]$cat xtrabackup_slave_info
SET GLOBAL gtid_purged='0c0b921a-5808-11e8-9b90-6c92bf623e12:1-589397257, f13130e5-5807-11e8-9b8f-7cd30ae4341e:1-725361734';
CHANGE MASTER TO MASTER_AUTO_POSITION=1;
主从配置过程:
mysql> stop slave;
Query OK, 0 rows affected (0.05 sec) mysql> SET GLOBAL gtid_purged='0c0b921a-5808-11e8-9b90-6c92bf623e12:1-589397257, f13130e5-5807-11e8-9b8f-7cd30ae4341e:1-725361734';
Query OK, 0 rows affected (0.00 sec) mysql> change master to master_host='rm-bp1i0***********cs.com',master_user='zh****in',master_port=3306,master_password='8*******',master_auto_position=1; mysql> start slave;
Query OK, 0 rows affected (0.16 sec) mysql> show slave status \G;
*************************** 1. row ***************************
Slave_IO_State: Queueing master event to the relay log
Master_Host: rm-b**************cs.com
Master_User: zh******in
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.024340
Read_Master_Log_Pos: 284315203
Relay_Log_File: hostname-relay-bin.000002
Relay_Log_Pos: 171740
Relay_Master_Log_File: mysql-bin.024340
Slave_IO_Running: Yes
Slave_SQL_Running: Yes