基于xtrabackup的主从同步

 

 

 

 

 

 

基于xtrabackup的主从同步

 

 

 

 

 

 

 

 

作者	刘畅
时间	2020-9-21

 

 

 

 

 

服务器版本：CentOS Linux release 7.5.1804

主机名	ip地址	服务器配置	安装软件	密码
mysql01	172.16.1.151	2核/2G/60G	01 mysql5.7.31(二进制版)，主节点。 02 percona-xtrabackup	mysql5.7@2021
mysql02	172.16.1.152	2核/2G/60G	01 mysql5.7.31(二进制版)，未初始化的空库，从节点。 02 percona-xtrabackup

 

 

 

 

目录

1 基于gtid方式增加从库 1

1.1 前提条件 1

1.2 主库操作(172.16.1.151) 4

1.3 从库操作(172.16.1.152) 5

1.4 补充 7

2 基于传统二进制增加从库 8

2.1 前提条件 8

2.2 主库操作(172.16.1.151) 11

2.3 从库操作(172.16.1.152) 12

 

1 基于gtid方式增加从库

1.1 前提条件

1 主库(172.16.1.151)my.cnf配置文件

# cat /etc/my.cnf

[client]

port = 3306

default-character-set = utf8

socket = /usr/local/mysql/data/mysql.sock

[mysql]

no-auto-rehash

[mysqld]

user = mysql

port = 3306

basedir = /usr/local/mysql

datadir = /usr/local/mysql/data

socket = /usr/local/mysql/data/mysql.sock

bind-address = 0.0.0.0

pid-file = /usr/local/mysql/data/mysqld.pid

character-set-server = utf8

collation-server = utf8_general_ci

log-error = /usr/local/mysql/data/mysqld.log

slow_query_log = ON

long_query_time = 2

slow_query_log_file = /usr/local/mysql/data/mysql-slow.log

max_connections = 10240

open_files_limit = 65535

innodb_buffer_pool_size = 1G

innodb_flush_log_at_trx_commit = 2

innodb_log_file_size = 256M

transaction_isolation = READ-COMMITTE

default-storage-engine = innodb

innodb_file_per_table = on

symbolic-links = 0

explicit_defaults_for_timestamp = 1

skip-name-resolve

lower_case_table_names = 1

server-id = 1

log-bin = /usr/local/mysql/data/mysql-bin

binlog_cache_size = 4M

binlog_format = mixed

max_binlog_cache_size = 8M

max_binlog_size = 512M

expire_logs_days = 14

gtid_mode = ON

enforce_gtid_consistency = ON

[mysqldump]

quick

max_allowed_packet = 32M

 

创建mysql用户

# groupadd -g 1600 mysql

# useradd -g mysql -u 1600 -M -s /sbin/nologin mysql

# id mysql

uid=1600(mysql) gid=1600(mysql) 组=1600(mysql)

 

初始化mysql数据库

# /usr/local/mysql/bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data

 

修改数据库密码

# grep 'temporary password' /usr/local/mysql/data/mysqld.log

2020-09-03T15:36:48.970741Z 1 [Note] A temporary password is generated for root@localhost: Kf;Aj:zNk7&3

# mysql -uroot -p'Kf;Aj:zNk7&3'

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'mysql5.7@2021';

mysql> exit;

 

创建复制账户

mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%' IDENTIFIED BY 'repl@2020';

 

2 从库(172.16.1.152)my.cnf配置文件

# cat /etc/my.cnf

[client]

port = 3306

default-character-set = utf8

socket = /usr/local/mysql/data/mysql.sock

[mysql]

no-auto-rehash

[mysqld]

user = mysql

port = 3306

basedir = /usr/local/mysql

datadir = /usr/local/mysql/data

socket = /usr/local/mysql/data/mysql.sock

bind-address = 0.0.0.0

pid-file = /usr/local/mysql/data/mysqld.pid

character-set-server = utf8

collation-server = utf8_general_ci

log-error = /usr/local/mysql/data/mysqld.log

slow_query_log = ON

long_query_time = 2

slow_query_log_file = /usr/local/mysql/data/mysql-slow.log

max_connections = 10240

open_files_limit = 65535

innodb_buffer_pool_size = 1G

innodb_flush_log_at_trx_commit = 2

innodb_log_file_size = 256M

transaction_isolation = READ-COMMITTE

default-storage-engine = innodb

innodb_file_per_table = on

symbolic-links = 0

explicit_defaults_for_timestamp = 1

skip-name-resolve

lower_case_table_names = 1

server-id = 2

slave-skip-errors=1007,1022,1050,1062,1169

relay-log=/usr/local/mysql/data/relay-log

max_relay_log_size=512M

relay-log-purge=ON

read-only

gtid_mode = ON

enforce_gtid_consistency = ON

[mysqldump]

quick

max_allowed_packet = 32M

 

创建mysql 用户

# groupadd -g 1600 mysql

# useradd -g mysql -u 1600 -M -s /sbin/nologin mysql

# id mysql

uid=1600(mysql) gid=1600(mysql) 组=1600(mysql)

 

3 mysqld.service

# cat /usr/lib/systemd/system/mysqld.service

[Unit]

Description=MySQL Server

Documentation=man:mysqld(8)

Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html

After=network.target

After=syslog.target

[Install]

WantedBy=multi-user.target

[Service]

User=mysql

Group=mysql

Type=forking

PIDFile=/usr/local/mysql/data/mysqld.pid

TimeoutSec=0

PermissionsStartOnly=true

# ExecStartPre=/usr/local/mysql/bin/mysqld_pre_systemd

ExecStart=/usr/local/mysql/bin/mysqld --defaults-file=/etc/my.cnf --daemonize --pid-file=/usr/local/mysql/data/mysqld.pid $MYSQLD_OPTS

EnvironmentFile=-/etc/sysconfig/mysql

LimitNOFILE = 65535

Restart=on-failure

RestartPreventExitStatus=1

PrivateTmp=false

1.2 主库操作(172.16.1.151)

1 登录主库创建库、表、数据

mysql> create database test;

mysql> use test;

mysql> create table user (name varchar(50));

mysql> insert into user(name) values("zhangsan");

mysql> show global variables like "%gtid%";

 

 

2 使用xtrabackup在线备份主库

# mkdir -p /mysql_backup/

# innobackupex -uroot -p"mysql5.7@2021" --stream=tar /mysql_backup/ 2>/dev/null |gzip >/mysql_backup/`date +%F_%H-%M-%S`.tar.gz

# du -sh /mysql_backup/2020-10-21_14-07-57.tar.gz

580K /mysql_backup/2020-10-21_14-07-57.tar.gz

 

3 将备份的主库发送到从库

# scp -rp /mysql_backup/2020-10-21_14-07-57.tar.gz root@172.16.1.152:/tmp/

1.3 从库操作(172.16.1.152)

1 解压主库备份

# mkdir -p /tmp/mysql_data/

# cd /tmp/mysql_data/

# tar -xzf /tmp/2020-10-21_14-07-57.tar.gz

# ls -l

 

 

2 回滚事务日志

# innobackupex --apply-log --redo-only /tmp/mysql_data/

 

3 完全还原备份库

# innobackupex --defaults-file=/etc/my.cnf --copy-back /tmp/mysql_data/

# ls -l --full-time /usr/local/mysql/data/

 

 

4 查看主库的binlog_pos点

# cat /usr/local/mysql/data/xtrabackup_info

 

binlog_pos = filename 'mysql-bin.000003', position '750', GTID of the last change '994634a3-f6fc-11ea-a9d8-000c290fbdd4:1-5'

 

5 启动从数据库

# chown -R mysql.mysql /usr/local/mysql/

# systemctl start mysqld

# cat /usr/local/mysql/data/auto.cnf

[auto]

server-uuid=6651dc51-1366-11eb-a67e-000c29c5b550

 

6 设置已执行过的gtid

# mysql -uroot -p'mysql5.7@2021'

mysql> reset slave;

# 清空从节点信息

mysql> reset master;

# 清空mysql.gtid_executed表信息

mysql> SET GLOBAL GTID_PURGED='994634a3-f6fc-11ea-a9d8-000c290fbdd4:1-5';

# 设置已执行过的gtid

mysql> show global variables like "%gtid%";

 

mysql> select * from mysql.gtid_executed;

 

 

7 配置连接主库信息

# mysql> CHANGE MASTER TO

MASTER_HOST='172.16.1.151',

MASTER_PORT=3306,

MASTER_USER='repl',

MASTER_PASSWORD='repl@2020',

MASTER_AUTO_POSITION=1;

 

8 启动主从复制

mysql> start slave;

mysql> show slave statusG;

 

 

1.4 补充

1 mysql.gtid_executed表

GTID持久化的介质，MySQL启动阶段会读取这个表来获取gtid_executed变量的值。mysql.gtid_executed表修改时机为在BINLOG发生切换的时候保存，直到上一个BINLOG文件

执行过的全部GTID，它不是实时更新的。

 

2 gtid_executed变量

MySQL数据库已经执行了哪些GTID事务，处于内存中。show slave status中的executed_gtid_set也取自这里。

 

3 gtid_purged变量

由于BINLOG文件的删除(如purge binary logfiles或者超过expire_logs_days设置)已经丢失的GTID事务，同时在搭建备库的我们使用set global gtid_purged变量来提示MySQL哪些GTID事务我已经执行过了。

 

4 通过percona-xtrabackup备份库，备份的是数据库及库中的表文件，其它文件不会备份(例如：主库的binlog文件，从库的relay-log、master.info文件)，当启动数据库时根据my.cnf文件再生成相应的文件。

2 基于传统二进制增加从库

2.1 前提条件

1 主库(172.16.1.151)my.cnf配置文件

# cat /etc/my.cnf

[client]

port = 3306

default-character-set = utf8

socket = /usr/local/mysql/data/mysql.sock

[mysql]

no-auto-rehash

[mysqld]

user = mysql

port = 3306

basedir = /usr/local/mysql

datadir = /usr/local/mysql/data

socket = /usr/local/mysql/data/mysql.sock

bind-address = 0.0.0.0

pid-file = /usr/local/mysql/data/mysqld.pid

character-set-server = utf8

collation-server = utf8_general_ci

log-error = /usr/local/mysql/data/mysqld.log

slow_query_log = ON

long_query_time = 2

slow_query_log_file = /usr/local/mysql/data/mysql-slow.log

max_connections = 10240

open_files_limit = 65535

innodb_buffer_pool_size = 1G

innodb_flush_log_at_trx_commit = 2

innodb_log_file_size = 256M

transaction_isolation = READ-COMMITTE

default-storage-engine = innodb

innodb_file_per_table = on

symbolic-links = 0

explicit_defaults_for_timestamp = 1

skip-name-resolve

lower_case_table_names = 1

server-id = 1

log-bin = /usr/local/mysql/data/mysql-bin

binlog_cache_size = 4M

binlog_format = mixed

max_binlog_cache_size = 8M

max_binlog_size = 512M

expire_logs_days = 14

[mysqldump]

quick

max_allowed_packet = 32M

 

创建mysql用户

# groupadd -g 1600 mysql

# useradd -g mysql -u 1600 -M -s /sbin/nologin mysql

# id mysql

uid=1600(mysql) gid=1600(mysql) 组=1600(mysql)

 

初始化mysql数据库

# /usr/local/mysql/bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data

 

修改数据库密码

# grep 'temporary password' /usr/local/mysql/data/mysqld.log

2020-09-03T15:36:48.970741Z 1 [Note] A temporary password is generated for root@localhost: Kf;Aj:zNk7&3

# mysql -uroot -p'Kf;Aj:zNk7&3'

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'mysql5.7@2021';

mysql> exit;

 

创建复制账户

mysql> GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%' IDENTIFIED BY 'repl@2020';

mysql> flush privileges;

 

2 从库(172.16.1.152)my.cnf配置文件

# cat /etc/my.cnf

[client]

port = 3306

default-character-set = utf8

socket = /usr/local/mysql/data/mysql.sock

[mysql]

no-auto-rehash

[mysqld]

user = mysql

port = 3306

basedir = /usr/local/mysql

datadir = /usr/local/mysql/data

socket = /usr/local/mysql/data/mysql.sock

bind-address = 0.0.0.0

pid-file = /usr/local/mysql/data/mysqld.pid

character-set-server = utf8

collation-server = utf8_general_ci

log-error = /usr/local/mysql/data/mysqld.log

slow_query_log = ON

long_query_time = 2

slow_query_log_file = /usr/local/mysql/data/mysql-slow.log

max_connections = 10240

open_files_limit = 65535

innodb_buffer_pool_size = 1G

innodb_flush_log_at_trx_commit = 2

innodb_log_file_size = 256M

transaction_isolation = READ-COMMITTE

default-storage-engine = innodb

innodb_file_per_table = on

symbolic-links = 0

explicit_defaults_for_timestamp = 1

skip-name-resolve

lower_case_table_names = 1

server-id = 2

slave-skip-errors=1007,1022,1050,1062,1169

relay-log=/usr/local/mysql/data/relay-log

max_relay_log_size=512M

relay-log-purge=ON

read-only

[mysqldump]

quick

max_allowed_packet = 32M

 

创建mysql 用户

# groupadd -g 1600 mysql

# useradd -g mysql -u 1600 -M -s /sbin/nologin mysql

# id mysql

uid=1600(mysql) gid=1600(mysql) 组=1600(mysql)

 

3 mysqld.service

# cat /usr/lib/systemd/system/mysqld.service

[Unit]

Description=MySQL Server

Documentation=man:mysqld(8)

Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html

After=network.target

After=syslog.target

[Install]

WantedBy=multi-user.target

[Service]

User=mysql

Group=mysql

Type=forking

PIDFile=/usr/local/mysql/data/mysqld.pid

TimeoutSec=0

PermissionsStartOnly=true

# ExecStartPre=/usr/local/mysql/bin/mysqld_pre_systemd

ExecStart=/usr/local/mysql/bin/mysqld --defaults-file=/etc/my.cnf --daemonize --pid-file=/usr/local/mysql/data/mysqld.pid $MYSQLD_OPTS

EnvironmentFile=-/etc/sysconfig/mysql

LimitNOFILE = 65535

Restart=on-failure

RestartPreventExitStatus=1

PrivateTmp=false

2.2 主库操作(172.16.1.151)

1 登录主库创建库、表、数据

mysql> reset master;

# 因为在上面我修改了root密码、创建了用于主从复制的'repl'@'%'用户，并刷新了

# 权限表，这些操作的pos点都被记录了下来，为了下面实验一致，我将binlog日

# 志重置，从重新开始。

mysql> create database test;

mysql> use test;

mysql> create table user (name varchar(50));

mysql> insert into user(name) values("zhangsan");

mysql> show master status;

 

 

2 使用xtrabackup在线备份主库

# mkdir -p /mysql_backup/

# innobackupex -uroot -p"mysql5.7@2021" --stream=tar /mysql_backup/ 2>/dev/null |gzip >/mysql_backup/`date +%F_%H-%M-%S`.tar.gz

# du -sh /mysql_backup/2020-10-21_16-23-39.tar.gz

580K /mysql_backup/2020-10-21_16-23-39.tar.gz

 

3 将备份的主库发送到从库

# scp -rp /mysql_backup/2020-10-21_16-23-39.tar.gz root@172.16.1.152:/tmp/

2.3 从库操作(172.16.1.152)

1 解压主库备份

# mkdir -p /tmp/mysql_data/

# cd /tmp/mysql_data/

# tar -xzf /tmp/2020-10-21_16-23-39.tar.gz

# ls -l --full-time

 

 

2 回滚事务日志

# innobackupex --apply-log --redo-only /tmp/mysql_data/

 

3 完全还原备份库

# innobackupex --defaults-file=/etc/my.cnf --copy-back /tmp/mysql_data/

# ls -l --full-time /usr/local/mysql/data/

 

 

4 查看主库的binlog_pos点

# cat /usr/local/mysql/data/xtrabackup_info

 

binlog_pos = filename 'mysql-bin.000001', position '750'

 

5 启动从数据库

# chown -R mysql.mysql /usr/local/mysql/

# systemctl start mysqld

# cat /usr/local/mysql/data/auto.cnf

[auto]

server-uuid=6651dc51-1366-11eb-a67e-000c29c5b550

 

6 清空主库信息

# mysql -uroot -pmysql5.7@2021

mysql> reset slave;

# 清空从节点信息

mysql> reset master;

# 清空mysql.gtid_executed表信息

 

7 配置连接主库信息

# mysql> CHANGE MASTER TO

MASTER_HOST='172.16.1.151',

MASTER_PORT=3306,

MASTER_USER='repl',

MASTER_PASSWORD='repl@2020',

MASTER_LOG_FILE='mysql-bin.000001',

MASTER_LOG_POS=750;

 

8 启动主从复制

mysql> start slave;

mysql> show slave statusG;