三台mysql5.7服务器互作主从配置案例

一、架构

三台msyql服务器221,222,223，每台服务器开两个实例，3306作为主库，3307作为另外一台服务器的从库

二、每台服务器安装双实例

参照：https://www.cnblogs.com/sky-cheng/p/10919447.html

进行双实例安装

三、每台服务器的3306实例创建一个复制账号

在172.28.5.221上

[root@push-- ~]# mysql -uroot -p -S /var/lib/mysql//mysql.sock
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7. MySQL Community Server (GPL)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

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,replication client on *.* to 'repl'@'%' identified by 'XXXXXXX';
Query OK,  rows affected,  warning (0.00 sec)

mysql> 

在172.28.5.222上

[root@push-- ~]# mysql -uroot -p -S /var/lib/mysql//mysql.sock
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7. MySQL Community Server (GPL)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

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,replication client on *.* to 'repl'@'%' identified by 'XXXXXXXX';
Query OK,  rows affected,  warning (0.01 sec)

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

mysql> 

在172.28.5.223上

[root@push-- ~]# mysql -uroot -p -S /var/lib/mysql//mysql.sock
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7. MySQL Community Server (GPL)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

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,replication client on *.* to 'repl'@'%' identified by 'xxxxxxxx';
Query OK,  rows affected,  warning (0.00 sec)
mysql> flush privileges;
Query OK,  rows affected (0.00 sec)

mysql> 

三、主从配置

1、首先设置好每个3306mysql实例的server_id参数为本机IP地址最后一位，3307实例server_id参数为本机IP地址最后一位再加端口号

在172.28.5.221服务器的3306配置文件中打开日志文件设置

[root@push-- ~]# vim /etc/mysql/my-.cnf 

# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html

[mysqld]
# innodb_buffer_pool_size = 128M
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
user=mysql
port=
datadir=/home/mysql-5.7./data/
socket=/var/lib/mysql//mysql.sock
server_id=
log-bin=master-
binlog_format=row
#skip-grant-tables
symbolic-links=
pid-file=/var/run/mysqld//mysqld.pid
log-error=/home/mysql-5.7./log//mysqld.log

[mysqld_safe]
log-error=/home/mysql-5.7./log//mysqld.log

server_id=221 设置server_id

log-bin=master-221 设置log_bin日志文件名

binlog_format=row 指定日志格式为row
2、重启3306实例，使配置生效

[root@push-- ~]# mysqladmin -uroot -p -S /var/lib/mysql//mysql.sock shutdown
[root@push-- ~]# mysqld_safe --defaults-file=/etc/mysql/my-.cnf &
[]
[root@push-- ~]# --27T02::.758733Z mysqld_safe Logging to '/home/mysql-5.7.26/log/3306/mysqld.log'.
--27T02::.813602Z mysqld_safe Starting mysqld daemon with databases from /home/mysql-5.7./data/

3、客户端连接

^C
[root@push-- ~]# mysql -uroot -p -S /var/lib/mysql//mysql.sock
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7.-log MySQL Community Server (GPL)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

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、显示server_id参数

mysql> show variables like '%server_id%';
+----------------+---------+
| Variable_name  | Value   |
+----------------+---------+
| server_id      |  |
| server_id_bits |       |
+----------------+---------+
 rows in set (0.00 sec)

5、显示主库状态

mysql> show master status\G;
*************************** . row ***************************
             File: master-221.000002
         Position:
     Binlog_Do_DB:
 Binlog_Ignore_DB:
Executed_Gtid_Set:
 row in set (0.00 sec)

ERROR:
No query specified

此时，需要记住上面的参数:  File: master-221.000001   Position: 154 ，日志文件名和偏移量，需要在从库上做主从设置时要用到这两个参数

6、从库设置

在172.28.5.222服务器上的3307配置文件

[mysqld]
# innodb_buffer_pool_size = 128M
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
user=mysql
port=
datadir=/home/mysql-5.7./data/
socket=/var/lib/mysql//mysql.sock
server_id=
symbolic-links=
pid-file=/var/run/mysqld//mysqld.pid
log-error=/home/mysql-5.7./log//mysqld.log

[mysqld_safe]
log-error=/home/mysql-5.7./log//mysqld.log

7、重启3307实例，使配置生效

[root@push-- ~]# mysqladmin -uroot -p -S /var/lib/mysql//mysql.sock shutdown
[root@push-- ~]# mysqld_safe --defaults-file=/etc/mysql/my-.cnf &
[]
[root@push-- ~]# --27T03::.550199Z mysqld_safe Logging to '/home/mysql-5.7.26/log/3307/mysqld.log'.
--27T03::.610157Z mysqld_safe Starting mysqld daemon with databases from /home/mysql-5.7./data/

8、查看相应参数

[root@push-- ~]# mysql -uroot -p -S /var/lib/mysql//mysql.sock
mysql> show variables like '%server_id%';
+----------------+---------+
| Variable_name  | Value   |
+----------------+---------+
| server_id      |  |
| server_id_bits |       |
+----------------+---------+
 rows in set (0.00 sec)

9、执行从库命令

mysql> change master to
    -> master_host='172.28.5.221',
    -> master_port=,
    -> master_user='repl',
    -> master_password='xxxxxxxx',
    -> master_log_file='master-221.000002',
    -> master_log_pos=;
Query OK,  rows affected,  warnings (0.31 sec)

10、启动从库

mysql> start slave;
Query OK,  rows affected (0.05 sec)

11、显示从库状态

mysql> start slave;
Query OK,  rows affected (0.05 sec)

mysql> show slave status\G;
*************************** . row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 172.28.5.221
                  Master_User: repl
                  Master_Port:
                Connect_Retry:
              Master_Log_File: master-221.000002
          Read_Master_Log_Pos:
               Relay_Log_File: push---relay-bin.
                Relay_Log_Pos:
        Relay_Master_Log_File: master-221.000002
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB:
          Replicate_Ignore_DB:
           Replicate_Do_Table:
       Replicate_Ignore_Table:
      Replicate_Wild_Do_Table:
  Replicate_Wild_Ignore_Table:
                   Last_Errno:
                   Last_Error:
                 Skip_Counter:
          Exec_Master_Log_Pos:
              Relay_Log_Space:
              Until_Condition: None
               Until_Log_File:
                Until_Log_Pos:
           Master_SSL_Allowed: No
           Master_SSL_CA_File:
           Master_SSL_CA_Path:
              Master_SSL_Cert:
            Master_SSL_Cipher:
               Master_SSL_Key:
        Seconds_Behind_Master:
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno:
                Last_IO_Error:
               Last_SQL_Errno:
               Last_SQL_Error:
  Replicate_Ignore_Server_Ids:
             Master_Server_Id:
                  Master_UUID: 3e61e5be-7dff-11e9--6c2b5992e632
             Master_Info_File: /home/mysql-5.7./data//master.info
                    SQL_Delay:
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

同步线程都已经启动成功、 

Exec_Master_Log_Pos: 154  同步主库日志文件偏移量跟主库的日志文件偏移量相同，说明已经完全同步

12、测试同步
在172.28.5.221上创建test库和test表，并插入一条记录

mysql> create database test;
Query OK,  row affected (0.12 sec)

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test               |
+--------------------+
mysql> use test;
Database changed
mysql> create table test( uid int, name varchar());
Query OK,  rows affected (0.43 sec)
mysql> insert into test(uid,name)values(,'aaaa');
Query OK,  row affected (0.14 sec)
mysql> select * from test;
+------+------+
| uid  | name |
+------+------+
|     | aaaa |
+------+------+
 row in set (0.00 sec)

此时，在172.28.5.222上连接从库3307

[root@push-- ~]# mysql -uroot -p -S /var/lib/mysql//mysql.sock
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7. MySQL Community Server (GPL)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

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 databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test               |
+--------------------+
 rows in set (0.00 sec)
mysql> use test;
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> show tables;
+----------------+
| Tables_in_test |
+----------------+
| test           |
+----------------+
 row in set (0.00 sec)

mysql> select * from test;
+------+------+
| uid  | name |
+------+------+
|     | aaaa |
+------+------+
 row in set (0.00 sec)

已经跟主库数据同步成功了。

同样在172.28.5.222上将3306配置文件打开

[mysqld]
#innodb_buffer_pool_size = 128M
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
user=mysql
port=
datadir=/home/mysql-5.7./data/
socket=/var/lib/mysql//mysql.sock
server_id=
log-bin=master-
binlog_format=row
#skip-grant-tables
symbolic-links=
pid-file=/var/run/mysqld//mysqld.pid
log-error=/home/mysql-5.7./log//mysqld.log

[mysqld_safe]
log-error=/home/mysql-5.7./log//mysqld.log

重启3306实例

[root@push-- ~]# mysqladmin -uroot -p -S /var/lib/mysql//mysql.sock shutdown
Enter password:
[root@push-- ~]# mysqld_safe --defaults-file=/etc/mysql/my-.cnf &
[]
[root@push-- ~]# --27T03::.804192Z mysqld_safe Logging to '/home/mysql-5.7.26/log/3306/mysqld.log'.
--27T03::.864191Z mysqld_safe Starting mysqld daemon with databases from /home/mysql-5.7./data/
[root@push-- ~]# mysql -uroot -p -S /var/lib/mysql//mysql.sock
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7.-log MySQL Community Server (GPL)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

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 variables like '%server_id%';
+----------------+---------+
| Variable_name  | Value   |
+----------------+---------+
| server_id      |  |
| server_id_bits |       |
+----------------+---------+
 rows in set (0.01 sec)

mysql> show msater status\G;
ERROR  (): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'msater status' at line
ERROR:
No query specified

mysql> show master status\G;
*************************** . row ***************************
             File: master-222.000001
         Position:
     Binlog_Do_DB:
 Binlog_Ignore_DB:
Executed_Gtid_Set:
 row in set (0.00 sec)

ERROR:
No query specified

显示主库状态

在172.28.5.223服务器上打开3307配置文件，将其设置为172.28.5.222的3306的从库

[root@push-- ~]# vim /etc/mysql/my-.cnf 

[mysqld]
# innodb_buffer_pool_size = 128M
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
user=mysql
port=
datadir=/home/mysql-5.7./data/
socket=/var/lib/mysql//mysql.sock
server_id=
#log-bin=master-
#binlog_format=row
#skip-grant-tables
symbolic-links=
pid-file=/var/run/mysqld//mysqld.pid
log-error=/home/mysql-5.7./log//mysqld.log

[mysqld_safe]
log-error=/home/mysql-5.7./log//mysqld.log

客户端连接，设置从库命令

[root@push-- ~]# mysql -uroot -p -S /var/lib/mysql//mysql.sock
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7. MySQL Community Server (GPL)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

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 variables like '%server_id%';
+----------------+---------+
| Variable_name  | Value   |
+----------------+---------+
| server_id      |  |
| server_id_bits |       |
+----------------+---------+
 rows in set (0.00 sec)
mysql> change master to
    -> master_host='172.28.5.222',
    -> master_port=,
    -> master_user='repl',
    -> master_password='xxxxxx',
    -> master_log_file='master-222.000001',
    -> master_log_pos=;
Query OK,  rows affected,  warnings (0.36 sec)

启动从库

mysql> start slave;
Query OK,  rows affected (0.05 sec)

mysql> show slave status\G;
*************************** . row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 172.28.5.222
                  Master_User: repl
                  Master_Port:
                Connect_Retry:
              Master_Log_File: master-222.000001
          Read_Master_Log_Pos:
               Relay_Log_File: push---relay-bin.
                Relay_Log_Pos:
        Relay_Master_Log_File: master-222.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB:
          Replicate_Ignore_DB:
           Replicate_Do_Table:
       Replicate_Ignore_Table:
      Replicate_Wild_Do_Table:
  Replicate_Wild_Ignore_Table:
                   Last_Errno:
                   Last_Error:
                 Skip_Counter:
          Exec_Master_Log_Pos:
              Relay_Log_Space:
              Until_Condition: None
               Until_Log_File:
                Until_Log_Pos:
           Master_SSL_Allowed: No
           Master_SSL_CA_File:
           Master_SSL_CA_Path:
              Master_SSL_Cert:
            Master_SSL_Cipher:
               Master_SSL_Key:
        Seconds_Behind_Master:
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno:
                Last_IO_Error:
               Last_SQL_Errno:
               Last_SQL_Error:
  Replicate_Ignore_Server_Ids:
             Master_Server_Id:
                  Master_UUID: de99b6b7--11e9-9a45-6c2b5992e6d2
             Master_Info_File: /home/mysql-5.7./data//master.info
                    SQL_Delay:
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count:
                  Master_Bind:
      Last_IO_Error_Timestamp:
     Last_SQL_Error_Timestamp:
               Master_SSL_Crl:
           Master_SSL_Crlpath:
           Retrieved_Gtid_Set:
            Executed_Gtid_Set:
                Auto_Position:
         Replicate_Rewrite_DB:
                 Channel_Name:
           Master_TLS_Version: 

此时，从库已经启动，并且同步线程启动成功，同步完毕

测试数据

在172.28.5.222的3306上创建test库个test表，并插入一条数据

mysql> create database test;
Query OK,  row affected (0.11 sec)

mysql> use test;
Database changed
mysql> create table test (uid int,name varchar());
Query OK,  rows affected (0.26 sec)
mysql> insert into test values(,'bbbb');
Query OK,  row affected (0.15 sec)
mysql> select * from test;
+------+------+
| uid  | name |
+------+------+
|     | bbbb |
+------+------+
 row in set (0.00 sec)

此时，在172.28.5.223上连接3307从库

[root@push-- ~]# mysql -uroot -p -S /var/lib/mysql//mysql.sock
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7. MySQL Community Server (GPL)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

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> use test;
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> select * from test;
+------+------+
| uid  | name |
+------+------+
|     | bbbb |
+------+------+
 row in set (0.00 sec)

数据同步成功。

同样在172.28.5.223的3306和172.28.5.221的3307做主从配置

编辑172.28.5.223的3306配置文件

[root@push-- ~]# vim /etc/mysql/my-.cnf 

[mysqld]
# innodb_buffer_pool_size = 128M
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
user=mysql
port=
datadir=/home/mysql-5.7./data/
socket=/var/lib/mysql//mysql.sock
server_id=
log-bin=master-
binlog_format=row
#skip-grant-tables
symbolic-links=
pid-file=/var/run/mysqld//mysqld.pid
log-error=/home/mysql-5.7./log//mysqld.log

[mysqld_safe]
log-error=/home/mysql-5.7./log//mysqld.log

重启3306实例

[root@push-- ~]# mysqladmin -uroot -p -S /var/lib/mysql//mysql.sock shutdown
Enter password:
[root@push-- ~]# mysqld_safe --defaults-file=/etc/mysql/my-.cnf &
[]
[root@push-- ~]# --27T03::.899652Z mysqld_safe Logging to '/home/mysql-5.7.26/log/3306/mysqld.log'.
--27T03::.965604Z mysqld_safe Starting mysqld daemon with databases from /home/mysql-5.7./data/
^C
[root@push-- ~]# mysql -uroot -p -S /var/lib/mysql//mysql.sock
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7.-log MySQL Community Server (GPL)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

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 variables like'%server_id%';
+----------------+---------+
| Variable_name  | Value   |
+----------------+---------+
| server_id      |  |
| server_id_bits |       |
+----------------+---------+
 rows in set (0.01 sec)

mysql> show master status \G
*************************** . row ***************************
             File: master-223.000001
         Position:
     Binlog_Do_DB:
 Binlog_Ignore_DB:
Executed_Gtid_Set:
 row in set (0.00 sec)

主库启动成功

在172.28.5.221的3307配置文件

[root@push-- ~]# vim /etc/mysql/my-.cnf 

# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html

[mysqld]
# innodb_buffer_pool_size = 128M
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
user=mysql
port=
datadir=/home/mysql-5.7./data/
socket=/var/lib/mysql//mysql.sock
server_id=

# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=

log-error=/home/mysql-5.7./log//mysqld.log
pid-file=/var/run/mysqld//mysqld.pid

[myqld_safe]
log-error=/home/mysql-5.7./log//mysqld.log

重启3307实例

[root@push-- ~]# mysqladmin -uroot -p -S /var/lib/mysql//mysql.sock shutdown
[root@push-- ~]# mysqld_safe --defaults-file=/etc/mysql/my-.cnf &
[]
[root@push-- ~]# --27T03::.427996Z mysqld_safe Logging to '/home/mysql-5.7.26/log/3307/mysqld.log'.
--27T03::.482868Z mysqld_safe Starting mysqld daemon with databases from /home/mysql-5.7./data/
^C
[root@push-- ~]# mysql -uroot -p -S /var/lib/mysql//mysql.sock
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7. MySQL Community Server (GPL)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

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 variables like '%server_id%';
+----------------+---------+
| Variable_name  | Value   |
+----------------+---------+
| server_id      |  |
| server_id_bits |       |
+----------------+---------+
 rows in set (0.01 sec)

执行从库命令

mysql> change master to
    -> master_host='172.28.5.223',
    -> master_port=,
    -> master_user='repl',
    -> master_password='Zaq1xsw@',
    -> master_log_file='master-223.000001',
    -> master_log_pos=;
Query OK,  rows affected,  warnings (0.42 sec)

mysql> start slave;
Query OK,  rows affected (0.06 sec)

mysql> 

测试数据

在172.28.5.223的3306创建test库和test表，并插入一条记录

mysql> create database test;
Query OK,  row affected (0.06 sec)

mysql> use test;
Database changed
mysql> create table test(id int,name varchar());
Query OK,  rows affected (0.34 sec)

mysql> insert into test values(,'ccc');
Query OK,  row affected (0.14 sec)

mysql> select * from test;
+------+------+
| id   | name |
+------+------+
|     | ccc  |
+------+------+
 row in set (0.00 sec)

在172.28.5.221的3307上查看

sion for the right syntax to use near 'database' at line
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test               |
+--------------------+
 rows in set (0.00 sec)

mysql> use test;
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> select * from test;
+------+------+
| id   | name |
+------+------+
|     | ccc  |
+------+------+
 row in set (0.00 sec)

数据同步成功

至此3台MYSQL服务器互为主从设置完毕。

四、多实例的启动和停止

停止3306实例:  mysqladmin -uroot -p -S /var/lib/mysql/3307/mysql.sock shutdown

启动3306实例: mysqld_safe --defaults-file=/etc/mysql/my-3306.cnf &

连接3306实例:mysql -uroot -p -S /var/lib/mysql/3306/mysql.sock