MySql主從配置(主從熱備份)

環境說明

系統：centos7.5
軟件版本：mysql-5.7.23-linux-glibc2.12-x86_64.tar.gz
安裝目錄：/usr/local/mysql
數據庫目錄：/data/mysql
數據庫root密碼：hc123456
A數據庫：192.168.2.72 主
B數據庫：192.168.2.73 從

數據庫同步帳號: sync
數據庫sync密碼: pcpaeyphmp

安裝MySql

兩臺分別都安裝

建立用戶,組

建立mysql組指定組id爲1200，建立mysql用戶指定用戶id爲1200默認組mysql

groupadd -g 1200 mysql
useradd -r -g mysql -u 1200 -s /sbin/nologin mysql

建立數據目錄

mysql數據庫數據存儲目錄

datadir=/data/mysql         # 數據庫數據存儲目錄
mkdir -p $datadir
basedir=/usr/local/mysql    # 數據庫安裝目錄

關閉Selinux

setenforce 0
sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config

安裝 jemalloc

配置軟件安裝源,安裝jemalloc適合多線程下內存分配管理,減小內存碎片

rm -rf /etc/yum.repos.d/*
curl -so /etc/yum.repos.d/epel-7.repo http://mirrors.aliyun.com/repo/epel-7.repo
curl -so /etc/yum.repos.d/Centos-7.repo http://mirrors.aliyun.com/repo/Centos-7.repo
sed -i '/aliyuncs.com/d' /etc/yum.repos.d/Centos-7.repo /etc/yum.repos.d/epel-7.repo
yum install -y jemalloc-devel

下載軟件,解壓

curl -OL http://mirrors.ustc.edu.cn/mysql-ftp/Downloads/MySQL-5.7/mysql-5.7.23-linux-glibc2.12-x86_64.tar.gz --progress
tar xvf mysql-5.7.23-linux-glibc2.12-x86_64.tar.gz
mv mysql-5.7.23-linux-glibc2.12-x86_64/ $basedir

配置服務

cp $basedir/support-files/mysql.server /etc/init.d/mysqld
sed -i "s@^basedir=.*@basedir=$basedir@" /etc/init.d/mysqld
sed -i "s@^datadir=.*@datadir=$datadir@" /etc/init.d/mysqld
chmod +x /etc/init.d/mysqld
chkconfig --add mysqld
chkconfig mysqld on

mysql配置文件

cat << EOF >/etc/my.cnf
[client]
port = 3306
socket = /tmp/mysql.sock
default-character-set = utf8mb4

[mysql]
prompt="MySQL [\\d]> "
no-auto-rehash

[mysqld]
skip-ssl
port = 3306
user = mysql
server-id = 1
bind-address = 0.0.0.0
log_timestamps = SYSTEM
socket = /tmp/mysql.sock

basedir = $basedir
datadir = $datadir
character-set-server = utf8mb4
pid-file = $datadir/mysql.pid
init-connect = 'SET NAMES utf8mb4'

back_log = 300
#skip-networking
skip-name-resolve

max_connections = 1000
max_connect_errors = 6000
open_files_limit = 65535
table_open_cache = 128
max_allowed_packet = 500M
binlog_cache_size = 1M
max_heap_table_size = 8M
tmp_table_size = 16M

read_buffer_size = 2M
read_rnd_buffer_size = 8M
sort_buffer_size = 8M
join_buffer_size = 8M
key_buffer_size = 4M

thread_cache_size = 8

query_cache_type = 1
query_cache_size = 8M
query_cache_limit = 2M

ft_min_word_len = 4

log_bin = mysql-bin
binlog_format = mixed
expire_logs_days = 7

slow_query_log = 1
long_query_time = 1
log_error = $datadir/mysql-error.log
slow_query_log_file = $datadir/mysql-slow.log

performance_schema = 0
explicit_defaults_for_timestamp

#lower_case_table_names = 1

skip-external-locking

default_storage_engine = InnoDB
#default-storage-engine = MyISAM
innodb_file_per_table = 1
innodb_open_files = 500
innodb_buffer_pool_size = 64M
innodb_write_io_threads = 4
innodb_read_io_threads = 4
innodb_thread_concurrency = 0
innodb_purge_threads = 1
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 2M
innodb_log_file_size = 32M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 90
innodb_lock_wait_timeout = 120

bulk_insert_buffer_size = 8M
myisam_sort_buffer_size = 8M
myisam_max_sort_file_size = 10M
myisam_repair_threads = 1

interactive_timeout = 28800
wait_timeout = 28800

[mysqldump]
quick
max_allowed_packet = 500M

[myisamchk]
key_buffer_size = 8M
sort_buffer_size = 8M
read_buffer = 4M
write_buffer = 4M
EOF

數據庫配置優化

cp /etc/my.cnf{,.bak}
Mem=`free -m | awk '/Mem:/{print $2}'`
sed -i "s@max_connections.*@max_connections = $((${Mem}/3))@" /etc/my.cnf
if [ ${Mem} -gt 1500 -a ${Mem} -le 2500 ]; then
    #  1500MB < 實際內存 <= 2500MB
    sed -i 's@^thread_cache_size.*@thread_cache_size = 16@' /etc/my.cnf
    sed -i 's@^query_cache_size.*@query_cache_size = 16M@' /etc/my.cnf
    sed -i 's@^myisam_sort_buffer_size.*@myisam_sort_buffer_size = 16M@' /etc/my.cnf
    sed -i 's@^key_buffer_size.*@key_buffer_size = 16M@' /etc/my.cnf
    sed -i 's@^innodb_buffer_pool_size.*@innodb_buffer_pool_size = 128M@' /etc/my.cnf
    sed -i 's@^tmp_table_size.*@tmp_table_size = 32M@' /etc/my.cnf
    sed -i 's@^table_open_cache.*@table_open_cache = 256@' /etc/my.cnf
elif [ ${Mem} -gt 2500 -a ${Mem} -le 3500 ]; then
    #  2500MB < 實際內存 <= 3500MB
    sed -i 's@^thread_cache_size.*@thread_cache_size = 32@' /etc/my.cnf
    sed -i 's@^query_cache_size.*@query_cache_size = 32M@' /etc/my.cnf
    sed -i 's@^myisam_sort_buffer_size.*@myisam_sort_buffer_size = 32M@' /etc/my.cnf
    sed -i 's@^key_buffer_size.*@key_buffer_size = 64M@' /etc/my.cnf
    sed -i 's@^innodb_buffer_pool_size.*@innodb_buffer_pool_size = 512M@' /etc/my.cnf
    sed -i 's@^tmp_table_size.*@tmp_table_size = 64M@' /etc/my.cnf
    sed -i 's@^table_open_cache.*@table_open_cache = 512@' /etc/my.cnf
elif [ ${Mem} -gt 3500 ]; then
    #  3500MB < 實際內存
    sed -i 's@^thread_cache_size.*@thread_cache_size = 64@' /etc/my.cnf
    sed -i 's@^query_cache_size.*@query_cache_size = 64M@' /etc/my.cnf
    sed -i 's@^myisam_sort_buffer_size.*@myisam_sort_buffer_size = 64M@' /etc/my.cnf
    sed -i 's@^key_buffer_size.*@key_buffer_size = 256M@' /etc/my.cnf
    sed -i 's@^innodb_buffer_pool_size.*@innodb_buffer_pool_size = 1024M@' /etc/my.cnf
    sed -i 's@^tmp_table_size.*@tmp_table_size = 128M@' /etc/my.cnf
    sed -i 's@^table_open_cache.*@table_open_cache = 1024@' /etc/my.cnf
fi

配置mysql庫文件

rm -rf /etc/ld.so.conf.d/mariadb-x86_64.conf
echo "$basedir/lib" > /etc/ld.so.conf.d/mysql.conf
ldconfig

初始化數據庫

添加libjemalloc模塊,初始化數據庫,啓動mysql服務

sed -i 's@executing mysqld_safe@executing mysqld_safe\nexport LD_PRELOAD=/usr/lib64/libjemalloc.so@' $basedir/bin/mysqld_safe
$basedir/bin/mysqld --initialize-insecure --user=mysql --basedir=$basedir --datadir=$datadir
chmod 600 /etc/my.cnf
chown mysql.mysql -R $datadir
systemctl start mysqld
lsof | grep jemalloc

添加環境變量

echo -e "\n# mysqld\nexport PATH=\$PATH:$basedir/bin" >> ~/.bashrc
. ~/.bashrc

初始化root密碼, 權限

mysql受權 127.0.0.1,local 表示僅本機, % 表示全部主機

RootPass=hc123456       # 數據庫root密碼
mysql -e "grant all privileges on *.* to root@'127.0.0.1' identified by \"${RootPass}\" with grant option;"
mysql -e "grant all privileges on *.* to root@'localhost' identified by \"${RootPass}\" with grant option;"
mysql -uroot -p${RootPass} -e "reset master;"

開啓root遠程登陸權限

mysql -uroot -p${RootPass} -e "grant all privileges on *.* to root@'%' identified by \"${RootPass}\" with grant option;"
# 查看數據庫用戶權限
mysql -uroot -p${RootPass} -e "select user,host,authentication_string from mysql.user;"

配置防火牆

firewall-cmd --zone=public --add-port=3306/tcp --permanent
firewall-cmd --reload

A數據庫配置

開啓二進制日誌

1.開啓binlog(數據庫二進制日誌),設置server-id,重啓mysql服務

cp /etc/my.cnf{,.`date +%F`}
sed -i '14a log-bin = mysql-bin' /etc/my.cnf
sed -i 's/server-id.*/server-id = 1/g' /etc/my.cnf
sed -i '18a log-bin-index = master-bin.index' /etc/my.cnf
systemctl restart mysqld

建立同步帳戶,受權

2.建立同步數據的用戶,受權容許192.168.2.0/24網絡使用sync用戶登陸

mysql -uroot -p${RootPass}
create user sync;
grant replication slave on *.* to 'sync'@'192.168.2.%' identified by 'pcpaeyphmp';
flush privileges;
show master status;
exit

# MySQL [(none)]> show master status;
# 記下 binlog文件的position（偏移）和File（日誌文件）的值)
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000002 |      797 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+

B數據庫配置

1.配置從庫只容許來自服務器線程或具備SUPER權限的數據庫用戶進行更新(root,sync),開啓binlog(數據庫二進制日誌),設置server-id,重啓mysql服務

cp /etc/my.cnf{,.`date +%F`}
sed -i '11a read-only' /etc/my.cnf
sed -i '15a log-bin = mysql-bin' /etc/my.cnf
sed -i 's/server-id.*/server-id = 2/g' /etc/my.cnf
sed -i '19a log-bin-index = master-bin.index' /etc/my.cnf
systemctl restart mysqld

配置鏈接A數據庫

mysql -uroot -p${RootPass}
change master to master_host='192.168.2.72',  # A數據庫 IP或主機名(需解析通)
master_port=3306,                             # A數據庫端口號
master_user='sync',                           # 同步帳號
master_password='pcpaeyphmp',                 # 同步帳號的密碼
master_log_file='mysql-bin.000002',           # A數據庫執行 show master status; 獲取的 File 值
master_log_pos=797;                           # A數據庫執行 show master status; 獲取的 Position 值
start slave;                                  # 啓動slave
show slave status\G;                          # 查看同步狀態
exit

# MySQL [(none)]> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.2.72
                  Master_User: sync
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000002
          Read_Master_Log_Pos: 797
               Relay_Log_File: localhost-relay-bin.000002
                Relay_Log_Pos: 320
        Relay_Master_Log_File: mysql-bin.000002
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
           ............................

# 保證如下兩項狀態爲 Yes 鏈接成功
Slave_IO_Running: Yes
Slave_SQL_Running: Yes

驗證

A建立數據庫

create database test_01;
show databases;

# MySQL [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test_01            |
+--------------------+

B查看數據庫

show databases;

# MySQL [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test_01            |
+--------------------+

排錯

Slave_IO_Running:     # 狀態不爲Yes

1.數據庫A與數據庫B之間網絡是否通暢
2.同步帳號的用戶權限,及是否容許數據庫B登陸
3.查看兩端server-id(不能相同) 使用mysql命令查看 show variables like 'server_id'; 此配置項在my.cnf
4.配置從鏈接主時 binlog 文件的 position（偏移）和 File（日誌文件）的值) 是否正確