Checking That MySQL Server Is Working

You can use the mysqladmin or mysqlshow commands to check that the MySQL server is up and running. Here's an example of how to check information about the MySQL server using the mysqladmin command.

# mysqladmin -u root -p version proc
Enter password: ********
mysqladmin  Ver 8.23 Distrib 3.23.57, for pc-linux-gnu on i686
Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL license
   
Server version       3.23.57
Protocol version     10
Connection           Localhost via UNIX socket
UNIX socket          /var/lib/mysql/mysql.sock
Uptime:              2 days 10 hours 47 min 35 sec
   
Threads: 1  Questions: 184  Slow queries: 0  Opens: 1  Flush tables: 3
Open tables: 1 Queries per second avg: 0.001
+----+------+----------+------+-------+------+-----+------------------+
| Id | User | Host     | db   |Command| Time |State| Info             |
+----+------+----------+------+-------+------+-----+------------------+
| 52 | root | localhost| mysql| Query | 0    |     | show processlist |
+----+------+----------+------+-------+------+-----+------------------+

Each of the two options to mysqladmin shown here provides useful information. The version information shows the mysqladmin version is 8.23 and the number assigned to this distribution of the mysql server is 3.23.57. The binary package was created for PC versions of Linux/GNU on the i686 processor. The connection to the server is through a UNIX socket (mysql.sock) on the local host. The server has been up for 2 days, 10 hours, 47 minutes, and 35 seconds. Statistics show that there is one thread (connection to the server) currently active. There have been 184 requests to the server.

The proc option shows that one client is currently connected to the server. That client is logged into MySQL as the root user on the localhost. The client that has an Id of 52 (which you could use, as the server's administrator, if you wanted to disconnect the user) is currently querying the MySQL database.

If the server were not running at the moment, the mysqladmin command shown above would result in a failure message:

mysqladmin: connect to server at 'localhost' failed.

Recommended remedies are to try to restart the server (by typing /etc/init.d/mysqld restart) or to make sure that the socket exists (/var/lib/mysql/mysql.sock).