centos 7 安装 mysql 8_centos mysql环境变量

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前言

      centos 7 安装 mysql 8 ，安装包直接在mysql官网下载，无需登录

一、linux设置

1.关闭防火墙

      检查防火墙状态
          systemctl status firewalld.service
      暂时关闭防火墙，下次启动时防火墙仍随系统启动而启动
          systemctl stop firewalld.service
      彻底永久关闭防火墙
           systemctl disable firewalld.service

      关闭SELINUX防火墙！
           vi /etc/selinux/config
      将内容
            SELINUX=enforcing
       更改为
            SELINUX=disabled

2.添加主机名 

        查看IP地址 ： ifconfig -a / ip a
        查看主机名 ： hostname
        然后修改/etc/hosts文件：
        vi /etc/hosts

        添加内容：ip 主机名

3.检查删除是否有安装过mysql

        CENTOS7: rpm -qa |grep mariadb

        rpm -e mariadb-libs-5.5.56-2.el7.x86_64 --nodeps 

4.添加环境变量

 
vim /etc/profile
export MYSQL_HOME="/usr/local/mysql"
export PATH="$PATH:$MYSQL_HOME/bin"

二、安装mysql

1.创建目录，用户组及用户

mkdir -p /usr/local/mysql
mkdir -p /data/mysql_data
mkdir -p /data/mysql_log
mkdir -p /data/log_bin
mkdir -p /data/log_redo
mkdir -p /data/log_relay
mkdir -p /data/tmp
groupadd mysql
useradd -g mysql mysql
chown -R mysql.mysql /data/mysql_data /data/mysql_log /data/log_bin /data/log_redo/  /data/log_relay /data/tmp 
chown -R mysql.mysql /usr/local/mysql

2.创建my.cnf文件

将隔离级别修改为读已提交（其它主流数据库默认隔离级别），可以提高并发度。

[mysqld]
# GENERAL #
user = mysql
collation_server=utf8mb4_general_ci
character_set_server=utf8mb4
default_storage_engine = InnoDB
server_id = 1
socket = /data/mysql_data/mysql.sock
pid-file = /data/mysql_data/mysql.pid
port = 3306
transaction-isolation = READ-COMMITTED
lower_case_table_names = 1
sql_generate_invisible_primary_key = on
 
# SAFETY #
max_allowed_packet = 1G 
max_connect_errors = 1000000
max_connections=3000
max_user_connections=2800
open_files_limit=65535
skip_name_resolve=ON
 
# DATA STORAGE #
datadir = /data/mysql_data
tmpdir = /data/tmp
 
# BINARY LOGGING #
binlog-ignore-db=mysql,information_schema,sys,performance_schema
binlog_format = ROW
log_bin = /data/log_bin/mysql_bin_3306
binlog_expire_logs_seconds=1269600
sync_binlog = 1
max_binlog_size = 512M 
 
# CACHES AND LIMITS #
tmp_table_size = 16M 
max_heap_table_size = 32M
thread_cache_size = 64
table_definition_cache = 4096
table_open_cache = 4096
 
# INNODB #
#innodb_data_home_dir = /data/mysql_data/ibdata/
innodb_data_file_path = ibdata1:128M;ibdata2:10M:autoextend
innodb_flush_method = O_DIRECT
innodb_lock_wait_timeout = 50
innodb_flush_log_at_trx_commit = 1
innodb_file_per_table = ON
innodb_buffer_pool_instances = 8
innodb_buffer_pool_size = 8G
 
# repl # 
#rpl_semi_sync_master_enabled=1 
#rpl_semi_sync_master_timeout=1000 
gtid_mode=on 
enforce-gtid-consistency=1
 
# REDOLOG #
innodb_log_group_home_dir = /data/log_redo/  
innodb_log_buffer_size=67108864
#innodb_log_file_size=256M
#innodb_log_files_in_group=4
innodb_redo_log_capacity=20m
 
 
# LOGGING #
log_error = /data/mysql_log/mysql_error_3306.log
log_queries_not_using_indexes=0
slow_query_log = 1
long_query_time = 10
log_slow_admin_statements=1
slow_query_log_file = /data/mysql_log/mysql_slow_3306.log
 
# RELAYLOG #
relay_log = /data/log_relay/relaylog
relay_log_index = /data/log_relay/relay.index
 
# SLAVE #
replica_load_tmpdir=/data/tmp
 
[client]
default_character_set=utf8mb4
socket = /data/mysql_data/mysql.sock
 

3.配置系统服务

cp -af /usr/local/mysql/support-files/mysql.server /etc/init.d/mysqld
 
#############################################
vi /etc/init.d/mysqld
修改两处位置：
basedir=/usr/local/mysql
datadir=/data/mysql_data
#############################################

4.初始化数据库

 
cd /usr/local/mysql/bin
 
./mysqld --initialize --lower-case-table-names=1 --user=mysql --basedir=/usr/local/mysql --datadir=/data/mysql_data

5.启动数据库及登录

service mysqld start
 
mysql -uroot -p   --然后这里出现Enter password:的时候直接按回车即可
 
 
cat /data/mysql_log/mysql_error_3306.log|grep password可以找到初始密码
 
登录之后修改初始密码：
alter user  user() identified by  '123456';

至此安装完毕