目录
- 1.gtid基本概念
- 2.gtid优点
- 3.gtid的工作原理
- 4.gtid比传统复制的优势
- 5.启动的方法
- 6.gtid(一主一从)配置
- 6.1环境：
- 6.2在主库上给从库授权：
- 6.3确保数据一致操作
- 6.4配置主库
- 6.5配置从库
- 6.6配置主从复制
- 7.gtid（一主俩从）
- 8.gtid（俩主一从）
- 1.最新环境
- 2.所有服务器均关闭防火墙或者放行防火墙
- 3.授权连接
- master01库授权普通用户
- slave进行连接
- master02授权普通用户
- slave进行连接
- 4.分别进行配置文件修改
- 5.分别重启
- 6.在进行gtid多主一从配置前，先引入一个概念
- 7.slave从库以root用户登录进行gtid配置
- gtid(俩主一从)测试：
- slave相关命令：
- 解决问题
1.gtid基本概念
mysql 5.6.5开始支持的，全局事务标识符（gtid（global transaction id））是创建的唯一标识符，并与在源（主）服务器上提交的每个事务相关联。
此标识符不但是唯一的，而且在给定复制设置中的所有服务器上都是唯一的。
所有交易和所有gtid之间都有一对一的映射关系 。
它由服务器id以及事务id组合而成。
这个全局事务id不仅仅在原始服务器上唯一，在所有存在主从关系 的mysql服务器上也是唯一的。
正是因为这样一个特性使得mysql的主从复制变得更加简单，以及数据库一致性更可靠。
一个gtid在一个服务器上只执行一次，避免重复执行导致数据混乱或者主从不一致。
2.gtid优点
保证同一个事务在某slave上绝对只执行一次，没有执行过的gtid事务总是会被执行。
不用像传统复制那样保证binlog的坐标准确，因为根本不需要binlog以及坐标。
故障转移到新的master的时候很方便，简化了很多任务。
很容易判断master和slave的数据是否一致。只要master上提交的事务在slave上也提交了，那么一定是一致的。
3.gtid的工作原理
1.当一个事务在主库端执行并提交时，产生gtid，一同记录到binlog日志中。
2.binlog传输到slave,并存储到slave的relaylog后，读取这个gtid的这个值设置gtid_next变量，即告诉slave，下一个要执行的gtid值。
3、sql线程从relay log中获取gtid，然后对比slave端的binlog是否有该gtid。
4、如果有记录，说明该gtid的事务已经执行，slave会忽略。
5、如果没有记录，slave就会执行该gtid事务，并记录该gtid到自身的binlog，在读取执行事务前会先检查其他session持有该gtid，确保不被重复执行。
6、在解析过程中会判断是否有主键，如果有就用二级索引，如果没有就用全部扫描。
4.gtid比传统复制的优势
1.更简单的实现故障转移（failover），不需要找log_file,log_pos
2.更简单的搭建主从复制
3.更加安全
4.gtid是连续没有空洞的，因此主数据库发生冲突时，可以添加空事件的方式进行跳过
5.启动的方法
- 方法一：如果是新搭建的服务器，直接启动即可
- 方法二：如果是以及跑的服务器，需要重启一下mysql server
启动前，先关闭master的写入，保证master端和slave端数据保持同步，所有slave需要加上skip_slave_start=1的配置参数，避免启动后还是使用之前的复制协议
6.gtid(一主一从)配置
6.1环境：
centos8.0 ip：192.168.136.239 有数据 hostname：mysql01
centos8.0 ip：192.168.136.219 无数据 hostname：mysql02
#二进制安装以及mysql自启动服务略
6.2在主库上给从库授权：
mysql> grant replication slave on *.* to 'slave'@'192.168.136.219' identified by 'slave'; query ok, 0 rows affected, 1 warning (0.00 sec) mysql> flush privileges; query ok, 0 rows affected (0.00 sec) #俩服务器均关闭防火墙 [root@mysql01 ~]# systemctl stop firewalld [root@mysql01 ~]# setenforce 0 [root@mysql02 ~]# systemctl stop firewalld [root@mysql02 ~]# setenforce 0 从库测试连接： [root@mysql02 ~]# mysql -u slave -p'slave' -h192.168.136.239 type 'help;' or '\h' for help. type '\c' to clear the current input statement. mysql>
6.3确保数据一致操作
1.对主库进行锁表 mysql> flush tables with read lock; 2.对主库进行全备 [root@mysql01 ~]# mysqldump -uroot -a > /clq/all-databases-20210519.sql 3.拷贝到从库主机上去 [root@mysql01 ~]# scp /clq/all-databases-20210519.sql root@192.168.136.219:/backup/ [root@mysql02 backup]# ll -rw-r--r--. 1 root root 873527 5月 19 16:40 all-databases-20210519.sql 4.从库上进行主库的恢复 [root@mysql02 backup]# mysql -uroot -phuawei0917@ < all-databases-20210519.sql
6.4配置主库
[mysqld] basedir = /usr/local/mysql datadir = /opt/data socket = /tmp/mysql.sock port = 3306 user = mysql pid-file = /opt/data/mysql.pid skip-name-resolve #skip-grant-tables log-bin = master_bin #开启主库日志 server-id = 10 #服务唯一标识id gtid-mode = on #gtid模式开启 enforce_gtid_consistency = on #强制gtid模式一致性 log-slave-updates = 1 #从库允许更新日志，同步操作日志 binlog_format = row #binlog日志格式为行格式, 默认是mixed混合模式 skip_slave_start = 1 #跳过从库开启，以主库开始开启 #重启 systemctl restart mysqld
6.5配置从库
[root@mysql02 data]# cat /etc/my.cnf [mysqld] basedir = /usr/local/mysql datadir = /opt/data socket = /tmp/mysql.sock port = 3306 user = mysql pid-file = /opt/data/mysql.pid skip-name-resolve #skip-grant-tables gtid_mode=on enforce_gtid_consistency=on server-id=20 log-bin=slave_binlog #开启从库日志 log_slave-updates=1 #从库允许更新 binlog_format=row #格式为行 skip-slave_start=1 #重启 systemctl restart mysqld
查看gtid状态情况
mysql> show variables like '%gtid%'; +----------------------------------+-----------+ | variable_name | value | +----------------------------------+-----------+ | binlog_gtid_simple_recovery | on | | enforce_gtid_consistency | on | | gtid_executed_compression_period | 1000 | | gtid_mode | on | | gtid_next | automatic | | gtid_owned | | | gtid_purged | | | session_track_gtids | off | +----------------------------------+-----------+ 8 rows in set (0.00 sec)
6.6配置主从复制
#从库上root登录配置 #help change master to 可以查看帮助文档实例
mysql> change master to
-> master_host='192.168.136.239',
-> master_user='slave',
-> master_password='slave',
-> master_port=3306, #主库端口
-> master_auto_position=1; #位置
#master_use_gtid = current_pos
query ok, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
query ok, 0 rows affected (0.00 sec)
mysql> show slave status\g;
slave_io_running: connecting
slave_io_running: yes
slave_sql_running: yes
保证系统一致性
授权一致性
（一主一从gtid）测试：
主库创建一个数据库test，进行测试查看
从库创建一个数据库test02，进行测试查看
#主库创建一个test数据库 mysql> create database test; mysql> show databases; +--------------------+ | database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | | test | +--------------------+ #从库上查看同步情况 mysql> show databases; +--------------------+ | database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | | test | +--------------------+ 6 rows in set (0.00 sec) #从库创建test02库 mysql> create database test02; query ok, 1 row affected (0.00 sec) #主库上查看 mysql> show databases; +--------------------+ | database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | #是没有test02库的 | test | +--------------------+ 5 rows in set (0.00 sec)
小结：主库上的数据操作会同步到从库上面去，而从库上的数据操作与主库没联系
7.gtid（一主俩从）
第三台mysql连接的话，相应配置
第3台mysql ，版本:centos8 ip:192.168.136.230 主机名:mysql03
[root@mysql03 ~]# cat /etc/my.cnf
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
socket = /tmp/mysql.sock
port = 3306
user = mysql
pid-file = /opt/data/mysql.pid
skip-name-resolve
#skip-grant-tables
# replication config
log-bin = master_bin
server-id = 21 #id必须与之前不同
gtid-mode = on
enforce-gtid-consistency = on
log-slave-updates = 1
binlog-format = row
skip-slave-start = 1
#查看gtid情况
mysql> show variables like '%gtid%';
+----------------------------------+-----------+
| variable_name | value |
+----------------------------------+-----------+
| binlog_gtid_simple_recovery | on |
| enforce_gtid_consistency | on |
| gtid_executed_compression_period | 1000 |
| gtid_mode | on |
| gtid_next | automatic |
| gtid_owned | |
| gtid_purged | |
| session_track_gtids | off |
+----------------------------------+-----------+
#由于之前只权限了一个ip，此刻在mysql01主数据库上再授权一个ip
mysql> grant replication slave on *.* to 'slave'@'192.168.136.230' identified by 'slave';
query ok, 0 rows affected, 1 warning (0.00 sec)
mysql> flush privileges;
query ok, 0 rows affected (0.00 sec)
#测试连接
[root@mysql ~]# mysql -uslave -pslave -h192.168.136.239
mysql: [warning] using a password on the command line interface can be insecure.
welcome to the mysql monitor. commands end with ; or \g.
your mysql connection id is 17
server version: 5.7.33-log mysql community server (gpl)
copyright (c) 2000, 2021, oracle and/or its affiliates.
oracle is a registered trademark of oracle corporation and/or its
affiliates. other names may be trademarks of their respective
owners.
type 'help;' or '\h' for help. type '\c' to clear the current input statement.
mysql>
#mysql03从库上root用户连接进行相应配置
[root@mysql03 ~]# mysql -uroot -p1
mysql> change master to
-> master_host='192.168.136.239', #主库ip
-> master_user='slave', #主库授权的普通用户
-> master_password='slave',
-> master_port=3306, #主库端口
-> master_auto_position=1; #位置从1开始同步
#也可以查看帮助进行配置
mysql> help change master to;
change master to
master_host='source2.example.com',
master_user='replication',
master_password='password',
master_port=3306,
master_log_file='source2-bin.001',
master_log_pos=4,
master_connect_retry=10;
url: https://dev.mysql.com/doc/refman/5.7/en/change-master-to.html
#开启
mysql> start slave;
mysql> show slave status\g;
*************************** 1. row ***************************
slave_io_state: waiting for master to send event
master_host: 192.168.136.239
master_user: slave
master_port: 3306
connect_retry: 60
master_log_file: master_bin.000002
read_master_log_pos: 2172
relay_log_file: mysql-relay-bin.000002
relay_log_pos: 2387
relay_master_log_file: master_bin.000002
slave_io_running: yes
slave_sql_running: yes #显示俩个yes则运行成功！
#mysql03查看数据库，数据库内容也同步成功
mysql> show databases;
+--------------------+
| database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| test |
+--------------------+
5 rows in set (0.00 sec)
8.gtid（俩主一从）
1.最新环境
| 版本 | ip | 主机名 | 身份 |
|---|---|---|---|
| centos8 | 192.168.136.239 | master01 | 主库 |
| centos8 | 192.168.136.219 | master02 | 主库 |
| centos8 | 192.168.136.230 | slave | 从库 |
2.所有服务器均关闭防火墙或者放行防火墙
[root@master01 ~]# systemctl stop firewalld [root@master01 ~]# systemctl disable firewalld [root@master02 ~]# systemctl stop firewalld [root@master02 ~]# systemctl disable firewalld [root@slave ~]# systemctl stop firewalld [root@slave ~]# systemctl disable firewalld
3.授权连接
master01库授权普通用户
mysql> grant replication slave on *.* to 'user'@'192.168.136.%' identified by 'user';
slave进行连接
[root@slave ~]# mysql -uuser -p'user' -h192.168.136.239 mysql: [warning] using a password on the command line interface can be insecure. welcome to the mysql monitor. commands end with ; or \g. your mysql connection id is 5 server version: 5.7.33 mysql community server (gpl) copyright (c) 2000, 2021, oracle and/or its affiliates. oracle is a registered trademark of oracle corporation and/or its affiliates. other names may be trademarks of their respective owners. type 'help;' or '\h' for help. type '\c' to clear the current input statement.
master02授权普通用户
mysql> grant replication slave on *.* to 'app'@'192.168.136.%' identified by 'app'; query ok, 0 rows affected, 1 warning (0.01 sec) mysql> flush privileges; query ok, 0 rows affected (0.00 sec)
slave进行连接
[root@slave ~]# mysql -uapp -papp -h192.168.136.219 mysql: [warning] using a password on the command line interface can be insecure. welcome to the mysql monitor. commands end with ; or \g. your mysql connection id is 3 server version: 5.7.33 mysql community server (gpl) copyright (c) 2000, 2021, oracle and/or its affiliates. oracle is a registered trademark of oracle corporation and/or its affiliates. other names may be trademarks of their respective owners. type 'help;' or '\h' for help. type '\c' to clear the current input statement. mysql>
4.分别进行配置文件修改
#master01主机：
[root@master01 ~]# cat /etc/my.cnf
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
socket = /tmp/mysql.sock
port = 3306
user = mysql
pid-file = /opt/data/mysql.pid
skip-name-resolve
skip-grant-tables
log-bin = master_bin
server-id = 10
gtid-mode = on
enforce-gtid-consistency = on
log-slave-updates = 1
binlog-format = row
skip-slave-start = 1
#master02主机
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
socket = /tmp/mysql.sock
port = 3306
user = mysql
pid-file = /opt/data/mysql.pid
skip-name-resolve
#replication config
log-bin = master_bin
server-id = 11
gtid-mode = on
enforce-gtid-consistency = on
log-slave-updates = 1
binlog-format = row
skip-slave-start = 1
#slave主机
[mysqld]
basedir = /usr/local/mysql
datadir = /opt/data
socket = /tmp/mysql.sock
port = 3306
user = mysql
pid-file = /opt/data/mysql.pid
skip-name-resolve
log-bin = slave_bin
server-id = 13
gtid-mode = on
enforce-gtid-consistency = on
log-slave-updates = 1
binlog-format = row
skip-slave-start = 1
5.分别重启
[root@master01 ~]# systemctl restart mysqld [root@master02 ~]# systemctl restart mysqld [root@slave ~]# systemctl restart mysqld
6.在进行gtid多主一从配置前，先引入一个概念
channel(频道)：每一个channel都是一个独立的slave服务，都有一个io_thread和sql_thread，原理和普通复制一样，只是需要在change master to语句后面使用for channel来进行区分slave
在使用channel时需要将从库的master-info-repository、relay-log-info-repository设置为table，否则会报错。
将信息存储库设置为table格式
方式一（mysql内设置）:
set global master_info_repository='table';
set global relay_log_info_repository='table';
方式二（/etc/my.cnf内设置）:
3.在my.cnf中设置
master_info_repository = table
relay_log_info_repository = table
#检查是否更改成功
mysql> show variables where variable_name in ('relay_log_info_repository','master_info_repository');
+---------------------------+-------+
| variable_name | value |
+---------------------------+-------+
| master_info_repository | table |
| relay_log_info_repository | table |
+---------------------------+-------+
7.slave从库以root用户登录进行gtid配置
#slave从库上配置俩个主库gtid复制
mysql> change master to
-> master_host='192.168.136.219', #mysql02主库ip
-> master_user='app', #mysql02主库授权的普通用户
-> master_password='app', #mysql02主库授权的普通用户密码
-> master_port=3306, #主库端口
-> master_auto_position=1 for channel 'master01'; #位置从1开始同步,并且第一个slave取名master01
mysql> change master to
-> master_host='192.168.136.239', #mysql01主库ip
-> master_user='user',
-> master_password='user',
-> master_port=3306, #主库端口
-> master_auto_position=1 for channel 'master02'; #位置从1开始同步,并且第一个slave取名master01
#查看俩个slave状态
mysql> show slave status\g;
*************************** 1. row ***************************
slave_io_state:
master_host: 192.168.136.219
master_user: app
master_port: 3306
connect_retry: 60
master_log_file:
read_master_log_pos: 4
relay_log_file: slave02-relay-bin-master1.000001
relay_log_pos: 4
relay_master_log_file:
slave_io_running: no
slave_sql_running: no #都是关闭的
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: 154
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
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: 0
master_uuid:
master_info_file: mysql.slave_master_info
sql_delay: 0
sql_remaining_delay: null
slave_sql_running_state:
master_retry_count: 86400
master_bind:
last_io_error_timestamp:
last_sql_error_timestamp:
master_ssl_crl:
master_ssl_crlpath:
retrieved_gtid_set:
executed_gtid_set: b4326a77-0a31-11ec-a991-000c298d3571:1-2,
d68b404d-0a35-11ec-9df1-000c29581959:1
auto_position: 1
replicate_rewrite_db:
channel_name: master1
master_tls_version:
*************************** 2. row ***************************
slave_io_state:
master_host: 192.168.136.239
master_user: user
master_port: 3306
connect_retry: 60
master_log_file:
read_master_log_pos: 4
relay_log_file: slave02-relay-bin-master2.000001
relay_log_pos: 4
relay_master_log_file:
slave_io_running: no
slave_sql_running: no
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: 154
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
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: 0
master_uuid:
master_info_file: mysql.slave_master_info
sql_delay: 0
sql_remaining_delay: null
slave_sql_running_state:
master_retry_count: 86400
master_bind:
last_io_error_timestamp:
last_sql_error_timestamp:
master_ssl_crl:
master_ssl_crlpath:
retrieved_gtid_set:
executed_gtid_set: b4326a77-0a31-11ec-a991-000c298d3571:1-2,
d68b404d-0a35-11ec-9df1-000c29581959:1
auto_position: 1
replicate_rewrite_db:
channel_name: master2
master_tls_version:
2 rows in set (0.00 sec)
#开启俩个slave
mysql> start slave;
#再次查看状态
gtid(俩主一从)测试：
#master01主库创建一个test数据库 mysql> create database test; query ok, 1 row affected (0.00 sec) mysql> show databases; +--------------------+ | database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | | test | +--------------------+ 5 rows in set (0.00 sec) #master02主库上查看 mysql> show databases; +--------------------+ | database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | #没有内容 +--------------------+ 4 rows in set (0.00 sec) #slave从库查看 mysql> show databases; +--------------------+ | database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | | test | #已经同步了test库 +--------------------+ 5 rows in set (0.00 sec) #mysql02主库创建一个rhca数据库 mysql> create database rhca; query ok, 1 row affected (0.01 sec) mysql> show databases; +--------------------+ | database | +--------------------+ | information_schema | | rhca | | mysql | | performance_schema | | sys | +--------------------+ 5 rows in set (0.00 sec) #slave从库 mysql> show databases; +--------------------+ | database | +--------------------+ | information_schema | | rhca | | mysql | | performance_schema | | sys | #有了mysql01主库的test库和mysql02的rhca的库 | test | +--------------------+ 6 rows in set (0.00 sec)
slave相关命令：
show slave status； //查看全部slave状态
show slave status for channel ‘naem’; //查看单个slave状态
reset slave; #重置全部slave
reset slave for channel ‘master1′; #重置单个slave
stop slave for channel ‘master1′; #暂停单个slave
start slave for channel ‘master1′; #开启单个slave
虽然我在做的过程没有遇到错误，但是下面这个是最最容易出现的错误
配置完开启slave出现报错
mysql> start slave; error 1872 (hy000): slave failed to initialize relay log info structure from the repository
解决问题
由于mysql.slave_relay_log_info表中保留了以前的复制信息，导致新从库启动时无法找到对应文件，那么我们清理掉该表中的记录即可
mysql> reset slave; query ok, 0 rows affected (0.00 sec)
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