解决xtrabackup备份时出现的socket报错

今天为公司新建的uat数据库备份时，出现了报错，将解决方法整理、做一下备忘：

服务器系统：

[root@uat-mysql-master tmp]# cat /etc/redhat-release
 CentOS Linux release 7.3.1611 (Core) 
mysql版本号：
mysql> select version();
+----------------+
| version()      |
+----------------+
| 5.5.47-cll-lve |
+----------------+
1 row in set (0.00 sec)

报错如下：

[root@uat-mysql-master tmp]# innobackupex  --defaults-file=/etc/my.cnf --user=backup --password=****** --stream=tar /home/backup/ | gzip >/home/backup/`date +%F_%H-%M-%S`.tar.gz
171120 17:10:42 innobackupex: Starting the backup operation
IMPORTANT: Please check that the backup run completes successfully.
           At the end of a successful backup run innobackupex
           prints "completed OK!".
    171120 17:10:42  version_check Connecting to MySQL server with DSN 'dbi:mysql:;mysql_read_default_group=xtrabackup' as 'backup'  (using password: YES).
Failed to connect to MySQL server: DBI connect(';mysql_read_default_group=xtrabackup','backup',...) failed: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2) at - line 1314.
171120 17:10:42 Connecting to MySQL server host: localhost, user: backup, password: set, port: not set, socket: not set
Failed to connect to MySQL server: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2).

解决办法：

在命令行中添加