在安装过程中所遇到的问题有: 1、my-default.cnf文件找不到 2、mysql启动报错 3、mysql临时密码无法登录

安装环境centos 6.0 下载数据库: [root@CLanguage src]# pwd /usr/local/src #下载文件存放路径(个人原因,可随意。) [root@CLanguage src]# wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.21-linux-glibc2.12-x86_64.tar.gz [root@CLanguage src]# tar -zxvf mysql-5.7.21-linux-glibc2.12-x86_64.tar.gz #解压 [root@CLanguage src]# mv mysql-5.7.21-linux-glibc2.12-x86_64 mysql
#更改文件名 卸载旧版本: [root@CLanguage src]# rpm -qa |grep mysql mysql-5.1.47-4.el6.x86_64 mysql-libs-5.1.47-4.el6.x86_64 mysql-devel-5.1.47-4.el6.x86_64 [root@CLanguage src]# rpm -e --nodeps mysql-5.1.47-4.el6.x86_64 [root@CLanguage src]# rpm -e --nodeps mysql-libs-5.1.47-4.el6.x86_64 [root@CLanguage src]# rpm -e --nodeps mysql-devel-5.1.47-4.el6.x86_64 [root@CLanguage src]# rpm -qa |grep mysql [root@CLanguage src]# 创建数据库目录以及用户和组: [root@CLanguage src]#mkdir /data [root@CLanguage src]#mkdir /data/mysqldata #数据存放目录 [root@CLanguage src]#groupadd mysql #创建mysql组 [root@CLanguage src]#useradd -r -s /sbin/nologin -g mysql mysql -d /usr/local/src/mysql #添加mysql用户使其shell模式为nologin(禁止登录), [root@CLanguage mysql]# chown -R mysql . [root@CLanguage mysql]# chgrp -R mysql . [root@CLanguage mysql]#chown -R mysql /data/mysqldata 安装前先安装numactl组件,或者会报错:bin/mysqld: error while loading shared libraries: libnuma.so.1 [root@CLanguage mysql]# yum -y install numactl
(可以使用本地CD yum源进行安装,前提是搭建好后。) 配置参数: [root@CLanguage src]# cd mysql [root@CLanguage mysql]# bin/mysqld --initialize --user=mysql --basedir=/usr/local/src/mysql --datadir=/data/mysqldata/ #配置参数 2018-01-31T08:41:32.144065Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details). 2018-01-31T08:41:34.501273Z 0 [Warning] InnoDB: New log files created, LSN=45790 2018-01-31T08:41:34.943351Z 0 [Warning] InnoDB: Creating foreign key constraint system tables. 2018-01-31T08:41:35.016168Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: 8b673fc1-0662-11e8-a70a-000c298536ba. 2018-01-31T08:41:35.021358Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened. 2018-01-31T08:41:35.025019Z 1 [Note] A temporary password is generated for root@localhost: dhaMrqAVZ5-C {最后的root@localhost:后面为临时密码}

--basedir=/usr/local/src/mysql #mysql文件所在目录 --datadir=/data/mysqldata/ #数据库存放目录 [root@CLanguage mysql]# bin/mysql_ssl_rsa_setup --datadir=/data/mysqldata/ #配置参数 修改系统配置文件: 在support-files目录未发现my-default.cnf文件,所以只能手动创建了。 [root@CLanguage support-files]# vim /etc/my.cnf (创建my.cnf,将以下代码复制进去,记得下面几个目录需要自己手动修改为自己定义的目录)

[client] port = 3306 socket = /tmp/mysql.sock

[mysqld] character_set_server=utf8 init_connect='SET NAMES utf8' basedir=/usr/local/src/mysql #文件存放目录 datadir=/data/mysqldata/ #数据库存放目录 socket=/tmp/mysql.sock #以上面socket值要一致 log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid lower_case_table_names = 1

sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION max_connections=5000

default-time_zone = '+8:00' (这里参数不全,可以去其他地方拷贝一个my.cnf文件) 或者拷贝以下内容: [mysqld] sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES # 一般配置选项 basedir = /usr/local/src/mysql #需修改 datadir = /data/mysqldata #需修改 port = 3306 socket = /var/run/mysqld/mysqld.sock character-set-server=utf8

back_log = 300 max_connections = 3000 max_connect_errors = 50 table_open_cache = 4096 max_allowed_packet = 32M #binlog_cache_size = 4M

max_heap_table_size = 128M read_rnd_buffer_size = 16M sort_buffer_size = 16M join_buffer_size = 16M thread_cache_size = 16 query_cache_size = 128M query_cache_limit = 4M ft_min_word_len = 8

thread_stack = 512K transaction_isolation = REPEATABLE-READ tmp_table_size = 128M #log-bin=mysql-bin long_query_time = 6

server_id=1

innodb_buffer_pool_size = 1G innodb_thread_concurrency = 16 innodb_log_buffer_size = 16M

innodb_log_file_size = 512M innodb_log_files_in_group = 3 innodb_max_dirty_pages_pct = 90 innodb_lock_wait_timeout = 120 innodb_file_per_table = on

[mysqldump] quick

max_allowed_packet = 32M

[mysql] no-auto-rehash default-character-set=utf8 safe-updates

[myisamchk] key_buffer = 16M sort_buffer_size = 16M read_buffer = 8M write_buffer = 8M

[mysqlhotcopy] interactive-timeout

[mysqld_safe] open-files-limit = 8192 [root@CLanguage support-files]# cp mysql.server /etc/init.d/mysqld [root@CLanguage support-files]# vim /etc/init.d/mysqld 修改/etc/init.d/mysqld在basedir和datadir后填入文件存放路径和数据存放路径 启动mysql: [root@CLanguage mysql]# bin/mysqld_safe --user=mysql & #检测 [root@CLanguage run]# /etc/init.d/mysql start (这里会报错,因为找不到mysqld文件夹,所以要创建并赋予权限。) [root@CLanguage mysql]# cd /var/run/ [root@CLanguage run]# mkdir mysqld [root@CLanguage run]# chown -R mysql mysqld [root@CLanguage run]# chgrp -R mysql mysqld [root@CLanguage run]# /etc/init.d/mysqld start Starting MySQL... [ OK ] 登录mysql已经修改密码: 如果使用bin/mysql -uroot -p无法登录时,可以使用以下办法进行密码重设: 修改/etc/my.cnf文件 在[mysqld]下面添加“skip-grant-tables” (skip-grant-tables命令为跳过验证,直接登录。个人认为好比linux的单用户模式,来进行mysql的密码修改。) 重启mysql 在命令行中输入bin/mysql进行登录(直接输入mysql命令可能提示找不到命令。因为path路径未设定,后面添加path路径说明。) mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | +--------------------+ 4 rows in set (0.00 sec)

mysql> USE mysql; #选择数据库 Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A

Database changed mysql> update user set authentication_string=password('123abc') where user='root'; Query OK, 0 rows affected, 1 warning (0.00 sec) Rows matched: 1 Changed: 0 Warnings: 1

mysql> flush privileges; #刷新权限 Query OK, 0 rows affected (0.00 sec)

mysql> quit; Bye 重新登录mysql [root@CLanguage run]#mysql -uroot -p123abc 修改完成后,注销my.cnf中的“skip-grant-tables” 修改环境变量: 将mysql的bin路径添加到/etc/profile [root@CLanguage mysql]# vim /etc/profile 添加: export PATH=/usr/local/src/mysql/bin:$PATH [root@CLanguage mysql]# source /etc/profile 配置mysql自动启动 [root@CLanguage mysql]#chmod 755 /etc/init.d/mysqld [root@CLanguage mysql]#chkconfig --add mysqld [root@CLanguage mysql]#chkconfig --level 345 mysqld on

在使用过程中,发现重启电脑,mysql无法启动。报PID文件找不到,存放PID文件的路径为:/var/run/mysqld下面,每次重启完在/var/run/目录中都找不到mysqld文件夹,都需要重新创建一次mysqld文件夹和修改文件夹的所属用户和组,才能正常使用。

解决方法 因为之所以/var/run/mysqld 目录每次重启后都需要手动去创建,是因为/var/run/目录下建立文件夹是在内存中,故每次重启后内存被清空导致/var/run/mysqld 也被清除,从而导致无法启动mysql。 创建一个mysqld.pid文件存放目录,重新修改文件夹所属用户和组。修改my.cnf文件,找到pid-file=/var/run/mysqld/mysqld.pid将mysqld.pid存放路径修改到其他存放位置。具体操作如下: 重新启动mysql正常运行。