mysql5.7的主从切换

mysql5.7的主从切换

主库： master 10.11.0.211
从库： slave  10.11.0.210

目标：主从切换，将slave切换为master，master切换为slave


一、使用innobackup进行主从同步设置

# 应用的连接数据库的账号配置
grant select,insert,update,delete on task.* to task_user@"%" identified by "cmslU6WFkX2pBylwINy2T";

# 修改root密码
update mysql.user set authentication_string = password('root'), password_expired = 'N', password_last_changed = now() where user = 'root';

# 设置主从同步：
# 备份主库
innobackupex --defaults-file="/etc/my.cnf" --user=root -p'root' --socket=/tmp/mysql.sock --apply-log --use-memory=1G /opt/2019-12-06_15-51-53
# 应用事务
innobackupex --defaults-file="/etc/my.cnf" --user=root --socket=/tmp/mysql.sock --copy-back /data/2019-12-06_15-51-53/

# 配置主从账号
grant replication slave,reload,super on *.* to rep@'%' identified by 'wsdb123';

# 记录主库的同步位置
[root@node1 data]# cat 2019-12-06_15-51-53/xtrabackup_binlog_info 
mysql_bin.000003    154

# 设置主从同步
change master to master_host='10.11.0.211',master_user='rep',master_password='wsdb123',master_log_file='mysql_bin.000003',master_log_pos=154;

二、进行主从切换操作:

1.锁定主数据写操作：

master: 
mysql> flush tables with read lock;

2然后修改从数据库为主要数据库：

1> 保证所有从数据库都已经执行了relay log中的全部更新，在从服务器中执行stop slave io_thread,用show processlist检查，查看状态是否是Has read all relay log,表示更新完成.
slave:
mysql>stop slave;
mysql>stop slave io_thread;

mysql>show processlistG
*************************** 2. row ***************************
Id: 2
User: system user
Host:
db: NULL
Command: Connect
Time: 4757
State: Has read all relay log; waiting for the slave I/O thread to update it
Info: NULL

2> 在从服务器上执行stop slave，reset master命令，重置成主数据库

mysql>stop slave;

mysql>reset master;

mysql>reset slave all;   -- 清除同步信息

3> 删除新的主服务器数据库目录中的master.info和relay-log.info文件，否则下次重启时还会按照从服务器来启动，
关闭新主库的my.cnf配置 read_only

4> 在新的主库中查看binlog日志
mysql> show master statusG;   

mysql> show master statusG
*************************** 1. row ***************************
             File: mysql_bin.000001
         Position: 154
     Binlog_Do_DB: 
 Binlog_Ignore_DB: 
Executed_Gtid_Set: 

重新设置主从同步，
附切换从数据库命令:

change master to master_host='10.11.0.210',master_user='rep', master_password='wsdb123', master_log_file='mysql_bin.000001', master_log_pos=154;
start slave;


5>从服务器上检测是否复制正常(Slave_IO_Running: Yes    &&  Slave_SQL_Running: Yes)

mysql> start slave;
Query OK, 0 rows affected (0.03 sec)

mysql> show slave statusG
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.11.0.210
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql_bin.000001
          Read_Master_Log_Pos: 154
               Relay_Log_File: mysql-relay-bin.000002
                Relay_Log_Pos: 320
        Relay_Master_Log_File: mysql_bin.000001



解锁定原主数据写操作：

mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)

#修改原主库的my.cnf 打开read_only参数

进行相应的应用检查

数据库的测试：
主库创建表，并插入数据：
MySQL [wanxing]> use wanxing;

Database changed
MySQL [wanxing]> show tables;
+-------------------+
| Tables_in_wanxing |
+-------------------+
| users             |
+-------------------+
1 row in set (0.00 sec)

MySQL [wanxing]> create table itpart(id int,name varchar(30)) ;
Query OK, 0 rows affected (0.01 sec)

MySQL [wanxing]> insert into itpart(1,'it engineer');


从库查询数据是否同步：
mysql> select * from itpart;
+------+-------------+
| id   | name        |
+------+-------------+
|    1 | it engineer |
+------+-------------+
1 row in set (0.01 sec)

生产环境切换记录：

主库和新主库都开启screen 窗口进行操作，避免网络中断引起操作异常
screen -S changemaster

准备工作：停止数据库的写入程序
停止监控

1.锁定老的主库写操作：

master: 
flush tables with read lock;
set global read_only=on;

show variables like 'read_only';

show master statusG;

2.然后修改从数据库为主要数据库：

1> 保证所有从数据库都已经执行了relay log中的全部更新，在从服务器中执行stop slave io_thread,用show processlist检查，查看状态是否是Has read all relay log,表示更新完成

slave:
mysql>stop slave;
mysql>stop slave io_thread;

mysql>show processlistG
*************************** 2. row ***************************
Id: 2
User: system user
Host:
db: NULL
Command: Connect
Time: 4757
State: Has read all relay log; waiting for the slave I/O thread to update it
Info: NULL

在从服务器上执行stop slave，reset master命令，重置成主数据库

mysql>stop slave;

mysql>reset master;

mysql>reset slave all;

# 打开可写操作
set global read_only=off;

3> 删除新的主服务器数据库目录中的master.info和relay-log.info文件，否则下次重启时还会按照从服务器来启动，
关闭新主库的my.cnf配置
read_only  注释掉

#### 修改/etc/hosts配置，进行

# db
172.16.0.239 inf.nei.prod.mysql.eus


4> 在新的主库中查看binlog日志

mysql> show master statusG
*************************** 1. row ***************************
             File: mysql_bin.000001
         Position: 154
     Binlog_Do_DB: 
 Binlog_Ignore_DB: 
Executed_Gtid_Set: 



重新设置主从同步，
附切换从数据库命令:

# 日志标记
change master to master_host='10.11.0.210',master_user='rep', master_password='wsdb123', master_log_file='mysql_bin.000001', master_log_pos=154;
start slave;

# 从库中执行
mysql> change master to master_host='172.16.0.239' ,master_user='rep',master_password='wsdb123',master_auto_position=1;
Query OK, 0 rows affected, 2 warnings (0.30 sec)

mysql> start slave;
Query OK, 0 rows affected (0.02 sec)


5>从服务器上检测是否复制正常(Slave_IO_Running: Yes    &&  Slave_SQL_Running: Yes)

mysql> start slave;
Query OK, 0 rows affected (0.03 sec)

mysql> show slave statusG
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.11.0.210
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql_bin.000001
          Read_Master_Log_Pos: 154
               Relay_Log_File: mysql-relay-bin.000002
                Relay_Log_Pos: 320
        Relay_Master_Log_File: mysql_bin.000001



解锁定原主数据写操作：

mysql> unlock tables;
Query OK, 0 rows affected (0.00 sec)

注意：
1.修改原主库的my.cnf 打开read_only参数，和relay-log相关参数
relay-log                                                   = mysql-relay-bin
relay-log-index                                             = relay.index

2.注意新主库的read_only参数是动态修改的，一定要修改my.cnf为off，或者直接删掉，避免重启后为on，应用不可写

进行相应的应用检查


后续工作：
1.数据库备份并且做主从同步
2.从库上做冷备份

添加监控


主库：8核32G配置参考

[:~]# cat /etc/my.cnf

# Example MySQL config file for medium systems.
# 8核 16G
# This is for a system with little memory (16G) where MySQL plays
[client]
#password       = your_password
port                                                        = 3306
socket                                                      = /tmp/mysql.sock

# The MySQL server
[mysqld]
user                                                        = mysql
port                                                        = 3306
bind-address                                                = 0.0.0.0
socket                                                      = /tmp/mysql.sock
datadir                                                     = /data/mysql_data
pid-file                                                    = /data/mysql_data/mysql.pid
basedir                                                     = /usr/local/mysql
tmpdir                                                      = /tmp

#此开关默认为NULL，即不允许导入导出。
#secure-file-priv                                           = /opt/upload

#-------------------------------gobal variables------------------------#
#默认关闭，涉及到timestamp类型的列自动更新的问题
explicit_defaults_for_timestamp                 = 1
###transaction_write_set_extraction              = XXHASH64  #以便在server收集写集合的同时将其记录到二进制日志。并且是行更改后的唯一标识此标识将用于检测冲突。
###loose-group_replication_group_name            = 'ce9be252-2b71-11e6-b8f4-00212889f856' #组的名字可以随便起,但不能用主机的GTID
###loose-group_replication_start_on_boot         = off  #为了避免每次启动自动引导具有相同名称的第二个组,所以设置为OFF。
###loose-group_replication_bootstrap_group       = off #同上
###loose-group_replication_local_address         = '192.168.1.88:33071' #写自己主机所在IP
###loose-group_replication_group_seeds           ='192.168.1.88:33071,192.168.1.89:33071,192.168.1.90:33071'
###loose-group_replication_single_primary_mode   = off  #关闭单主模式的参数
###loose-group_replication_enforce_update_everywhere_checks = on #开启多主模式的参数

skip-external-locking
skip-name-resolve
skip-ssl

#memory is 16G
key_buffer_size                                             = 16M
table_open_cache                                            = 2048
table_definition_cache                                      = 1024
sort_buffer_size                                            = 4M
net_buffer_length                                           = 32K
read_buffer_size                                            = 4M
read_rnd_buffer_size                                        = 16M

open_files_limit                                            = 10000
thread_cache_size                                           = 400
query_cache_type                                            = 0
query_cache_size                                            = 32M
max_write_lock_count                                        = 300
wait_timeout                                                = 28800
interactive_timeout                                         = 28800
net_read_timeout                                            = 1200
net_write_timeout                                           = 1200

max_connections                                             = 800
max_user_connections                                        = 750
max_connect_errors                                          = 10000
max_allowed_packet                                          = 256M
back_log                                                    = 2048
log_timestamps                                              = system
performance_schema                                          = OFF
character_set_server                                        = utf8mb4

##当链接数耗尽后，通过设置别用端口，让root可以登录
extra_max_connections                                       = 2
extra_port                                                  = 13306

###让mysql不区分大小写敏感
lower_case_table_names                                      = 1

#explicit_defaults_for_timestamp                            = 1

#----------------Myisam--------------------------------#
myisam_recover_options                                      = DEFAULT
bulk_insert_buffer_size                                     = 32M
myisam_sort_buffer_size                                     = 64M
myisam_max_sort_file_size                                   = 256M
myisam_repair_threads                                       = 1

#if the query is exec time great than 2 seconds, the query will log to slow log if slowlog is enabled.
long_query_time                                             = 3
slow_query_log                                              = On
slow-query-log-file                                         = /data/mysql_data/slow.log
show_compatibility_56                                       = on

# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
# 
#skip-networking

#----------------------------MySQL Log----------------#
# Replication Master Server (default)
# binary logging is required for replication
log-bin                                                     = mysql-bin
expire_logs_days                                            = 10
log_error                                                   = error.log
log_error_verbosity                                         = 1
log_warnings                                                = 1

# binary logging format - mixed recommended
binlog_format                                               = row
relay-log                                                   = mysql-relay-bin
relay-log-index                                             = relay.index
# required unique id between 1 and 2^32 - 1
server-id                                                   = 239
#sql-mode                                                    = "NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
#sql-mode                                                    = "NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION"
sync_binlog                                                 = 1
log_slave_updates                                           = 1
#binlog_checksum                                            = NONE
#slave_skip_errors = 1062,1032

#------------------------------replicate--------------#
#排除不需要同步的库表
#replicate-ignore-db                                        = mysql
#replicate-ignore-db                                        = sys
replicate-ignore-db                                         = information_schema
replicate-ignore-db                                         = performance_schema
replicate-ignore-db                                         = undolog
replicate-ignore-db                                         = for_nagios
replicate-ignore-db                                         = undolog

#replicate_wild_ignore_table                                = mysql.%
#replicate_wild_ignore_table                                = sys.%
replicate_wild_ignore_table                                 = information_schema.%
replicate_wild_ignore_table                                 = performance_schema.%
replicate_wild_ignore_table                                 = undolog.%
replicate_wild_ignore_table                                 = for_nagios.%
replicate_wild_ignore_table                                 = undolog.%

#主主复制需要开启
#auto_increment_offset= 2
#auto_increment_increment= 2

#GTID模式复制，需要开启如下
gtid_mode                                                  = ON
enforce_gtid_consistency                                   = ON

#并发复制
slave-parallel-type                                         = LOGICAL_CLOCK
slave-parallel-workers                                      = 2
master_info_repository                                      = TABLE
relay_log_info_repository                                   = TABLE
relay_log_recovery                                          = ON

#跳过slave进程启动参数
skip-slave-start

#如果实例为从库，则需要设置为on
#read_only                                                   = off

#skip-grant-tables

#--------------------------------------------------------innoDB------------#
innodb_rollback_on_timeout
# Uncomment the following if you are using InnoDB tables
innodb_data_home_dir                                        = /data/mysql_data
innodb_data_file_path                                       = ibdata1:1G;ibdata2:1G:autoextend
innodb_log_group_home_dir                                   = /data/mysql_data
innodb_undo_directory                                       = /data/mysql_data/undolog/
innodb_undo_logs                                            = 128
innodb_undo_tablespaces                                     = 3

# You can set .._buffer_pool_size up to 50 - 80 %
#innodb_use_sys_malloc = 0 
#innodb_page_size = 8192
innodb_buffer_pool_size                                     = 12G
innodb_buffer_pool_instances                                = 1
#innodb_additional_mem_pool_size = 8M

# Set .._log_file_size to 25 % of buffer pool size
innodb_log_file_size                                        = 256M
innodb_log_buffer_size                                      = 64M
innodb_log_files_in_group                                   = 3
#每次事务提交时MySQL都会把log buffer的数据写入log file，并且flush(刷到磁盘)中去，该模式为系统默认
innodb_flush_log_at_trx_commit                              = 1
innodb_lock_wait_timeout                                    = 120
#启用独立表空间
innodb_file_per_table                                       = 1

#CPU是1颗8核的，那么可以设置
innodb_read_io_threads                                      = 8
innodb_write_io_threads                                     = 8

#默认是0，则表示没有并发线程数限制，所有请求都会直接请求线程执行，当并发用户线程数量小于64，建议设置innodb_thread_concurrency=0，在大多数情况下，最佳的值是小于并接近虚拟CPU的个数
innodb_thread_concurrency                                   = 12
innodb_max_dirty_pages_pct                                  = 75
innodb_flush_method                                         = O_DIRECT

innodb_purge_threads                                        = 10
innodb_large_prefix                                         = 1

#参数待测试
#innodb_io_capacity                                         = 20000
#innodb_io_capacity_max                                     = 40000

#根据CPU核心数来设定
thread_pool_size                                            = 8
#thread_handling = pool-of-threads
thread_pool_oversubscribe                                   = 24

#thread_handling                             = pool-of-threads
thread_pool_stall_limit                                     = 100
thread_pool_max_threads                                     = 30

#解释： 在启动时把热数据加载到内存。
innodb_buffer_pool_load_at_startup                          = 1
#解释： 在关闭时把热数据dump到本地磁盘
innodb_buffer_pool_dump_at_shutdown                         = 1

##默认是8M, 如果一次insert数据量比较多的话, 可以适当增加
innodb_autoextend_increment                                 = 32

[mysqldump]
quick
max_allowed_packet                                          = 512M

[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates

[myisamchk]
#key_buffer_size = 20M
#sort_buffer_size = 20M
key_buffer_size                                             = 200M
sort_buffer_size                                            = 200M
read_buffer                                                 = 2M
write_buffer                                                = 2M

[mysqld_safe]
#控制文件打开数的show global status like 'open%file%';比较合适的设置：Open_files / open_files_limit * 100% <= 75%
open-files-limit                                            = 65535
log-error                                                   = /data/mysql_data/error.log

[mysqlhotcopy]
interactive-timeout

#启用存储过程、触发器的权限，但是会不适合于主从复制机制，会导致数据的不一致
log_bin_trust_function_creators                    = 1