mysql安裝指南

1配置準備

安裝使用普通使用者(本次安裝統一使用mysql使用者)，安裝包使用mysql-5.7.35-el7-x86_64.tar.gz解壓版安裝。

2. mysql安裝

2.1 軟體下載

linux機器wget下載：wget https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.35-el7-x86_64.tar.gz

win機器瀏覽器/下載工具：https://cdn.mysql.com//Downloads/MySQL-5.7/mysql-5.7.35-el7-x86_64.tar.gz

2.2 壓縮包上傳

fileZilla或者ftp工具上傳壓縮包到 /home/mysql/ 目錄下

2.3 壓縮包解壓縮以及更名

[mysql@es03-qa ~]$ tar -zxvf mysql-5.7.35-el7-x86_64.tar.gz

2.4 修改啟動檔案

命令
[mysql@es03-qa support-files]$ cd /home/mysql/mysql/support-files
[mysql@es03-qa support-files]$ vim mysql.server
#檔案修改 原檔案
# Set some defaults
mysqld_pid_file_path=
if test -z "$basedir"
then
  basedir=/usr/local/mysql
  bindir=/usr/local/mysql/bin
  if test -z "$datadir"
  then
    datadir=/usr/local/mysql/data
  fi
  sbindir=/usr/local/mysql/bin
  libexecdir=/usr/local/mysql/bin
else
  bindir="$basedir/bin"
  if test -z "$datadir"
  then
    datadir="$basedir/data"
  fi
  sbindir="$basedir/sbin"
  libexecdir="$basedir/libexec"
fi

#修改後

# Set some defaults
mysqld_pid_file_path=
if test -z "$basedir"
then
  basedir=/home/mysql/mysql5.7.3
  bindir=/home/mysql/mysql5.7.3/bin
  if test -z "$datadir"
  then
    datadir=/home/mysql/mysql5.7.3/data
  fi
  sbindir=/home/mysql/mysql5.7.3/bin
  libexecdir=/home/mysql/mysql5.7.3/bin
else
  bindir="$basedir/bin"
  if test -z "$datadir"
  then
    datadir="$basedir/data"
  fi
  sbindir="$basedir/sbin"
  libexecdir="$basedir/libexec"
fi
 

2.5 初始化

[mysql@es03-qa mysql5.7.3]$ bin/mysqld --initialize --user=mysql --basedir=/home/mysql/mysql5.7.3 --datadir=/home/mysql/mysql5.7.3/data
2021-09-14T10:17:20.574181Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2021-09-14T10:17:20.920371Z 0 [Warning] InnoDB: New log files created, LSN=45790
2021-09-14T10:17:20.974696Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2021-09-14T10:17:21.034047Z 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: f2657f22-1544-11ec-8b09-000c2938bea4.
2021-09-14T10:17:21.035010Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2021-09-14T10:17:21.945763Z 0 [Warning] A deprecated TLS version TLSv1 is enabled. Please use TLSv1.2 or higher.
2021-09-14T10:17:21.945797Z 0 [Warning] A deprecated TLS version TLSv1.1 is enabled. Please use TLSv1.2 or higher.
2021-09-14T10:17:21.946862Z 0 [Warning] CA certificate ca.pem is self signed.
2021-09-14T10:17:22.745792Z 1 [Note] A temporary password is generated for root@localhost: _LpSGgy9rXOi
#以上為初始化生成的隨機密碼

2.6 授權操作

[mysql@es03-qa mysql5.7.3]$ bin/mysql_ssl_rsa_setup --basedir=/home/mysql/mysql5.7.3 --datadir=/home/mysql/mysql5.7.3/data

2.7 配置mysql使用者環境變數

[mysql@es03-qa ~]$ vim ~/.bash_profile
#檔案修改前
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/.local/bin:$HOME/bin

export PATH

修改後
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/.local/bin:$HOME/bin
PATH=/home/mysql/mysql5.7.3/bin:$PATH
export PATH

2.8 centos7系列刪除mariadb 需要root

[root@es03-qa ~]# rpm -qa|grep mariadb
mariadb-libs-5.5.60-1.el7_5.x86_64
[root@es03-qa ~]# rpm -e --nodeps mariadb-libs-5.5.60-1.el7_5.x86_64

2.9 服務啟停

[mysql@es03-qa support-files]$ pwd
/home/mysql/mysql5.7.3/support-files
[mysql@es03-qa support-files]$ ./mysql.server start
Starting MySQL.[  OK  ]
[mysql@es03-qa support-files]$ mysql.server status #檢視狀態
[mysql@es03-qa support-files]$ mysql.server stop #停止mysql

2.10 配置服務自啟動

[root@es03-qa ~]# cp /home/mysql/mysql5.7.3/support-files/mysql.server /etc/init.d/mysqld
[root@es03-qa ~]# vim /usr/lib/systemd/system/mysql.service

[Unit]
Description=MySQL Server
After=network.target
After=syslog.target
[Service]
User=mysql
Group=mysql
Type=forking
PermissionsStartOnly=false
ExecStart= /etc/init.d/mysqld start
ExecStop= /etc/init.d/mysqld stop
ExecReload= /etc/init.d/mysqld restart
LimitNOFILE = 5000
[Install]
WantedBy=multi-user.target

[root@es03-qa ~]# systemctl daemon-reload #重新載入一下服務的配置檔案
[root@es03-qa ~]# systemctl  start  mysql.service #開啟mysql服務
[root@es03-qa ~]# systemctl  stop   mysql.service  #關閉mysql服務
[root@es03-qa ~]# systemctl  enable   mysql.service  #配置開機自啟

3.mysql資料庫的配置

3.1資料庫有關配置

[mysql@es03-qa support-files]$ mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.35

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> SET PASSWORD=PASSWORD('123456');  #密碼重置
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> ALTER USER 'root'@'localhost' PASSWORD EXPIRE NEVER;
Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
[mysql@es03-qa support-files]$ mysql -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.35 MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

4.主從庫的配置

1.另一臺mysql 配置同2，3步驟

[mysql@app01-qa support-files]$ cd /home/mysql/mysql/support-files
[mysql@app01-qa support-files]$ vim mysql.server
#檔案修改 原檔案
# Set some defaults
mysqld_pid_file_path=
if test -z "$basedir"
then
  basedir=/usr/local/mysql
  bindir=/usr/local/mysql/bin
  if test -z "$datadir"
  then
    datadir=/usr/local/mysql/data
  fi
  sbindir=/usr/local/mysql/bin
  libexecdir=/usr/local/mysql/bin
else
  bindir="$basedir/bin"
  if test -z "$datadir"
  then
    datadir="$basedir/data"
  fi
  sbindir="$basedir/sbin"
  libexecdir="$basedir/libexec"
fi

#修改後

# Set some defaults
mysqld_pid_file_path=
if test -z "$basedir"
then
  basedir=/home/mysql/mysql5.7.3
  bindir=/home/mysql/mysql5.7.3/bin
  if test -z "$datadir"
  then
    datadir=/home/mysql/mysql5.7.3/data
  fi
  sbindir=/home/mysql/mysql5.7.3/bin
  libexecdir=/home/mysql/mysql5.7.3/bin
else
  bindir="$basedir/bin"
  if test -z "$datadir"
  then
    datadir="$basedir/data"
  fi
  sbindir="$basedir/sbin"
  libexecdir="$basedir/libexec"
fi
[mysql@app01-qa mysql5.7.3]$ bin/mysqld --initialize --user=mysql --basedir=/home/mysql/mysql5.7.3 --datadir=/home/mysql/mysql5.7.3/data
2021-09-14T11:01:52.836212Z 0 [Warning] Changed limits: max_open_files: 1024 (requested 5000)
2021-09-14T11:01:52.836537Z 0 [Warning] Changed limits: table_open_cache: 431 (requested 2000)
2021-09-14T11:01:52.837060Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2021-09-14T11:01:53.076230Z 0 [Warning] InnoDB: New log files created, LSN=45790
2021-09-14T11:01:53.134881Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2021-09-14T11:01:53.192914Z 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: 2b209518-154b-11ec-bc32-000c290007c6.
2021-09-14T11:01:53.193924Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2021-09-14T11:01:54.929055Z 0 [Warning] A deprecated TLS version TLSv1 is enabled. Please use TLSv1.2 or higher.
2021-09-14T11:01:54.929080Z 0 [Warning] A deprecated TLS version TLSv1.1 is enabled. Please use TLSv1.2 or higher.
2021-09-14T11:01:54.929833Z 0 [Warning] CA certificate ca.pem is self signed.
2021-09-14T11:01:55.231616Z 1 [Note] A temporary password is generated for root@localhost: +F<4cr*zf;wP
[mysql@app01-qa ~]$ vim ~/.bash_profile
#檔案修改前
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/.local/bin:$HOME/bin

export PATH

修改後
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
        . ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/.local/bin:$HOME/bin
PATH=/home/mysql/mysql5.7.3/bin:$PATH
export PATH
[root@app01-qa ~]# rpm -qa|grep mariadb
mariadb-libs-5.5.60-1.el7_5.x86_64
[root@app01-qa ~]# rpm -e --nodeps mariadb-libs-5.5.60-1.el7_5.x86_64
[mysql@app01-qa support-files]$ ./mysql.server start
Starting MySQL.[  OK  ]
[mysql@app01-qa support-files]$ pwd
/home/mysql/mysql5.7.3/support-files
[mysql@app01-qa support-files]$ ./mysql.server start
Starting MySQL.[  OK  ]
[mysql@app01-qa support-files]$ mysql.server status #檢視狀態
[mysql@app01-qa support-files]$ mysql.server stop #停止mysql

[mysql@app01-qa support-files]$ mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.35

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> SET PASSWORD=PASSWORD('123456');  #密碼重置
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> ALTER USER 'root'@'localhost' PASSWORD EXPIRE NEVER;
Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
[mysql@app01-qa support-files]$ mysql -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.35 MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

2 主庫配置

1.mysql配置

[mysql@app01-qa support-files]$ mysql -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.35 MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> grant replication slave on *.* to 'repl_user'@'192.168.1.200' identified by 'repl_user';
Query OK, 0 rows affected, 1 warning (0.00 sec)
# repl_user是我們建立專門用來備份資料庫的使用者
	192.168.1.200是從mysql伺服器的ip,注意在部署的時候要根據實際情況替換掉
	identified後面的repl_user是repl_user的密碼

mysql> create database taizhitech;
Query OK, 1 row affected (0.00 sec)
#taizhi使用者配置遠端登陸
mysql> CREATE USER 'repl_user'@'%' IDENTIFIED BY 'repl_user'; 
Query OK, 0 rows affected (0.01 sec)
#taizhi使用者配置本地登入
mysql> CREATE USER 'repl_user'@'localhost' IDENTIFIED BY 'repl_user';
Query OK, 0 rows affected (0.00 sec)
# 給taizhi使用者操作taizhitech的許可權：
mysql> grant all privileges on taizhitech.* to repl_user;
Query OK, 0 rows affected (0.00 sec)
# 給使用者taizhi在所有登陸ip的許可權：
mysql> grant all privileges on *.* to 'rep1_user'@'%' identified by 'repl_user';
Query OK, 0 rows affected, 1 warning (0.00 sec)
#重新整理許可權
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
#使用測試
mysql> use taizhitech
Database changed
mysql> create table TEST(id int(6),name varchar(20));
Query OK, 0 rows affected (0.01 sec)

mysql> insert into TEST values(1,'wuji');
Query OK, 1 row affected (0.01 sec)

mysql> insert into TEST values(2,'zhaomin');
Query OK, 1 row affected (0.00 sec)

mysql> Select * from TEST;
+------+---------+
| id   | name    |
+------+---------+
|    1 | wuji    |
|    2 | zhaomin |
+------+---------+
2 rows in set (0.00 sec)

2 配置檔案配置

[mysql@es03-qa support-files]$ pwd
/home/mysql/mysql5.7.3/support-files
[mysql@es03-qa support-files]$ vim my-default.cnf #文末新增內容如下
[mysql@es03-qa support-files]$ cat my-default.cnf 
log_bin=mysql-bin
binlog_format = mixed
server_id =1
read-only=0
binlog-do-db=taizhitech
binlog-ignore-db=information_schema
binlog-ignore-db=performance_schema
binlog-ignore-db=mysql
binlog-ignore-db=test
auto-increment-increment=2
auto-increment-offset=1

[mysql@es03-qa support-files]$ cp my-default.cnf /home/mysql/mysql5.7.3/my.cnf
[mysql@es03-qa support-files]$ ./mysql.server restart

3 主節點狀態

[mysql@es03-qa support-files]$ mysql -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.35-log MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show master status\G
*************************** 1. row ***************************
             File: mysql-bin.000001
         Position: 353
     Binlog_Do_DB: taizhitech
 Binlog_Ignore_DB: information_schema,performance_schema,mysql,test
Executed_Gtid_Set: 
1 row in set (0.00 sec)

3 從庫配置

[mysql@app01-qa support-files]$ pwd
/home/mysql/mysql5.7.3/support-files
[mysql@app01-qa support-files]$ vim my-default.cnf #文末新增內容如下
[mysql@app01-qa support-files]$ cat my-default.cnf 
log-bin = mysql-bin
binlog_format = mixed
server_id = 2
replicate-do-db=eipdb
replicate-ignore-db=information_schema
replicate-ignore-db=performance_schema
replicate-ignore-db=mysql
replicate-ignore-db=test
relay_log=mysqld-relay-bin
log-slave-updates = ON

[mysql@app01-qa support-files]$ cp my-default.cnf /home/mysql/mysql5.7.3/my.cnf
[mysql@app01-qa support-files]$ ./mysql.server restart
Shutting down MySQL..[  OK  ]
Starting MySQL.[  OK  ]
[mysql@app01-qa support-files]$ mysql -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.35-log MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> CHANGE MASTER TO MASTER_HOST='192.168.1.199', MASTER_USER='repl_user', 
    -> MASTER_PASSWORD='repl_user',  MASTER_LOG_FILE='mysql-bin.000002',  MASTER_LOG_POS=353;
Query OK, 0 rows affected, 2 warnings (0.00 sec)

#引數註釋
## CHANGE MASTER TO
##    -> MASTER_HOST='192.168.1.199',主資料庫的ip，部署時根據實際情況，將其替換
##    -> MASTER_USER='repl_user',備份資料庫使用者
##    -> MASTER_PASSWORD='repl_user',備份資料庫密碼
##    -> MASTER_LOG_FILE='mysql-bin.000001', 主庫show master status\G
##	  -> MASTER_LOG_POS=154;主庫show master status\G

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

mysql>  flush privileges;
Query OK, 0 rows affected (0.00 sec)

[mysql@app01-qa support-files]$ ./mysql.server restart
Shutting down MySQL..[  OK  ]
Starting MySQL.[  OK  ]
[mysql@app01-qa support-files]$ mysql -uroot -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.35-log MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.1.199
                  Master_User: repl_user
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 154
               Relay_Log_File: mysqld-relay-bin.000003
                Relay_Log_Pos: 320
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes #節點執行情況
            Slave_SQL_Running: Yes #節點執行情況
              Replicate_Do_DB: taizhitech
          Replicate_Ignore_DB: information_schema,performance_schema,mysql,test
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 0
                   Last_Error: 
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 154
              Relay_Log_Space: 528
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error: 
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 1
                  Master_UUID: f2657f22-1544-11ec-8b09-000c2938bea4
             Master_Info_File: /home/mysql/mysql5.7.3/data/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 
            Executed_Gtid_Set: 
                Auto_Position: 0
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

5 mysql啟動失敗解決方案

[mysql@es03-qa support-files]$ ./mysql.server start
Starting MySQL./home/mysql/mysql5.7.3/bin/mysqld_safe: line 626: /var/log/mariadb/mariadb.log: No such file or directory
2021-09-14T10:30:04.106531Z mysqld_safe error: log-error set to '/var/log/mariadb/mariadb.log', however file don't exists. Create writable for user 'mysql'.
/home/mysql/mysql5.7.3/bin/mysqld_safe: line 144: /var/log/mariadb/mariadb.log: No such file or directory
The server quit without updating PID file (/var/lib/mysql/es03-qa.pid).[FAILED]

出現這個的原因有很多種，下面來分析一下mysql的各個檔案：

(1) mysql.server，在/home/mysql/mysql5.7.3/support-files/下。這是個指令碼檔案，這個指令碼的主要作用就是為了方便啟動和關閉mysql服務。它包含mysqld和mysqld_safe，這兩者都可以用來啟動指令碼。

(2) 日誌檔案，在/home/mysql/mysql5.7.3/data/下，以hostname.err命名，本例為[email protected]。

(3) sock檔案，在/tmp/目錄下，有mysql.sock和mysql.sock.lock兩個檔案。

mysql.sock.lock裡面是mysql的程序號。重啟mysql就會自動更新或者建立。

mysql.sock，這是本機啟動mysql需要的檔案。一般重啟mysql就會自動建立。這個檔案不存在，mysql可以啟動，但是進入mysql命令列客戶端會報錯：# mysql 出錯ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/data/mysql.sock'。

(4) pid檔案,在/home/mysql/mysql5.7.3/data/下，以hostname.pid命名，本例為[email protected]。裡面存放的是mysql的程序號。啟動mysql就會自動建立，關閉mysql就會消失。只要沒有啟動起來，pid檔案就不存在，就會報上面的錯誤。

(5) my.cnf配置檔案,一般在/etc/下。

啟動mysql時，它首先會依次尋找my.cnf這個配置檔案。（若都沒有my.cnf檔案，會另外自動尋找別的配置檔案）

Default options are read from the following files in the given order:
/etc/my.cnf /etc/mysql/my.cnf /usr/local/mysql/etc/my.cnf ~/.my.cnf

如上所示，它會先尋找/etc，再找/etc/mysql，再找/user/local/mysql,再找本地安裝目錄下的my.cnf。並且它的優先順序是遞增的，/etc最低，本地安裝目錄最高，優先順序高的my.cnf會覆蓋優先順序低的my.cnf。

總結一下，解決這個問題的幾種方法。

（1）My.cnf引起的問題

若電腦之前安裝過別的版本的mysql，它在其他地方生成了my.cnf檔案，而mysql5.7.3這個版本並不會自動生成my.cnf檔案，這就會導致它啟動時還會用之前的my.cnf檔案，所以無法啟動。解決這個辦法，有兩種途徑。1是把my.cnf檔案全部刪除，2是在優先順序最高的本地安裝目錄建一個新的my.cnf檔案。這裡現在比較簡單的第二種解決方法。

解決方法：

[mysql@es03-qa support-files]$ pwd
/home/mysql/mysql5.7.3/support-files
[mysql@es03-qa support-files]$ cp my-default.cnf /home/mysql/mysql5.7.3/my.cnf
[mysql@es03-qa support-files]$ cd ..
[mysql@es03-qa support-files]$ vim my.cnf
#檔案修改 原檔案
# Set some defaults
mysqld_pid_file_path=
if test -z "$basedir"
then
  basedir=/usr/local/mysql
  bindir=/usr/local/mysql/bin
  if test -z "$datadir"
  then
    datadir=/usr/local/mysql/data
  fi
  sbindir=/usr/local/mysql/bin
  libexecdir=/usr/local/mysql/bin
else
  bindir="$basedir/bin"
  if test -z "$datadir"
  then
    datadir="$basedir/data"
  fi
  sbindir="$basedir/sbin"
  libexecdir="$basedir/libexec"
fi

#修改後

# Set some defaults
mysqld_pid_file_path=
if test -z "$basedir"
then
  basedir/home/mysql/mysql5.7.3
  bindir=/home/mysql/mysql5.7.3/bin
  if test -z "$datadir"
  then
    datadir=/home/mysql/mysql5.7.3/data
  fi
  sbindir=/home/mysql/mysql5.7.3/bin
  libexecdir=/home/mysql/mysql5.7.3/bin
else
  bindir="$basedir/bin"
  if test -z "$datadir"
  then
    datadir="$basedir/data"
  fi
  sbindir="$basedir/sbin"
  libexecdir="$basedir/libexec"
fi

# log-error是錯誤日誌存放的位置，系統預設放在/home/mysql/mysql5.7.3/data下的es03-qa.err。
# pid-file是存放程序號的檔案系統預設會在啟動時在/home/mysql/mysql5.7.3/data目錄下自動建立一個es03-qa.pid。
[mysqld_safe]
log-error=
pid-file=  
#儲存退出 重啟mysql

（2）多餘的mysql程序引起的問題

[mysql@es03-qa support-files]$  ps -ef|grep mysqld
mysql    26286     1  0 18:34 pts/0    00:00:00 /bin/sh /home/mysql/mysql5.7.3/bin/mysqld_safe --datadir=/home/mysql/mysql5.7.3/data --pid-file=/home/mysql/mysql5.7.3/data/es03-qa.pid
mysql    26377 26286  0 18:34 pts/0    00:00:01 /home/mysql/mysql5.7.3/bin/mysqld --basedir=/home/mysql/mysql5.7.3 --datadir=/home/mysql/mysql5.7.3/data --plugin-dir=/home/mysql/mysql5.7.3/lib/plugin --log-error=es03-qa.err --pid-file=/home/mysql/mysql5.7.3/data/es03-qa.pid
mysql    27610 26241  0 18:47 pts/0    00:00:00 grep --color=auto mysqld

[mysql@es03-qa support-files]$ Kill -9 26377

（3）sock檔案引起的問題。

啟動mysql時，mysql.sock和mysql.sock.lock沒有及時更新，需要使用命令：rm -rf mysql.sock，rm -rf mysql.sock.lock。然後再啟動mysql服務，它就會及時生成新的sock檔案。

（4）mysql-bin.index引起的問題。

去mysql的資料目錄/data看看，如果存在mysql-bin.index，就趕快把它刪除掉。可能是第二次在機器上安裝mysql，有殘餘資料影響了服務的啟動。

6 主從配置失敗

在從資料庫配置時：

輸入命令：show slave status\G，執行後看到Slave_IO_Running和Slave_SQL_Running沒有為Yes。那表示沒有配置成功（廢話）。

我遇到的情況是這樣：

mysql> show slave status\G
Slave_IO_Running: Yes
Slave_SQL_Running: No

解決方法：

（1）先stop slave，停掉slave服務

（2）到主伺服器上檢視主機狀態：
記錄File和Position對應的值。

mysql> show master status\G
*************************** 1. row ***************************
             File: mysql-bin.000002
         Position: 1593
     Binlog_Do_DB: taizhitech
 Binlog_Ignore_DB: information_schema,performance_schema,mysql,test
Executed_Gtid_Set: 
1 row in set (0.00 sec)

（3）到slave伺服器上執行手動同步：
mysql> change master to
> master_host='192.168.219.119',
> master_user='repl_user',
> master_password='repl2016',
> master_port=3306,
> master_log_file='mysql-bin.000002',
> master_log_pos=3153;

（4）再次檢視slave狀態發現：
Slave_IO_Running: Yes
Slave_SQL_Running: Yes

不過也有可能出現：

mysql> show slave status\G
Slave_IO_Running: No
Slave_SQL_Running: Yes

解決方法：

（1）在主資料庫的命令列客戶端：看一下是否授權給

mysql> show grants for 'repl_user'@'192.168.1.200';
+---------------------------------------------------------------+
| Grants for [email protected]                            |
+---------------------------------------------------------------+
| GRANT REPLICATION SLAVE ON *.* TO 'repl_user'@'192.168.1.200' |
+---------------------------------------------------------------+

（2）根據之上的結果。已經賦予了許可權。

[mysql@app01-qa ~]$ mysql -uroot -h 192.168.1.199 -p123456
mysql: [Warning] Using a password on the command line interface can be insecure.
ERROR 1045 (28000): Access denied for user 'root'@'app01-qa' (using password: YES)
[mysql@app01-qa ~]$ mysql -urepl_user -h 192.168.1.199 -prepl_user
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.7.35-log MySQL Community Server (GPL)

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> exit
Bye

（3）好像也登陸進去了。於是再一次執行了第一個的解決方法，先停掉slave，再設定，再重啟資料庫。

（4）於是在檢視從資料庫的狀態，都是yes了