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Wednesday, December 3, 2008

Starting and Stopping MySQL Automatically

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Keywords: MySQL, Linux, Daemon, Services, Start Automatically

Starting and Stopping MySQL Automatically

Generally, you start the mysqld server in one of these ways:

  • By invoking mysqld directly. This works on any platform.

  • By running the MySQL server as a Windows service. This can be done on versions of Windows that support services (such as NT, 2000, XP, and 2003). The service can be set to start the server automatically when Windows starts, or as a manual service that you start on request. 

  • By invoking mysqld_safe, which tries to determine the proper options for mysqld and then runs it with those options. This script is used on Unix and Unix-like systems.

  • By invoking mysql.server. This script is used primarily at system startup and shutdown on systems that use System V-style run directories, where it usually is installed under the name mysql. Themysql.server script starts the server by invoking mysqld_safe

  • On Mac OS X, you can install a separate MySQL Startup Item package to enable the automatic startup of MySQL on system startup. The Startup Item starts the server by invoking mysql.server.

The mysqld_safe and mysql.server scripts and the Mac OS X Startup Item can be used to start the server manually, or automatically at system startup time. mysql.server and the Startup Item also can be used to stop the server.

To start or stop the server manually using the mysql.server script, invoke it with start or stop arguments:

shell> mysql.server start
shell> mysql.server stop

Before mysql.server starts the server, it changes location to the MySQL installation directory, and then invokesmysqld_safe. If you want the server to run as some specific user, add an appropriate user option to the [mysqld]group of the /etc/my.cnf option file, as shown later in this section. (It is possible that you will need to editmysql.server if you've installed a binary distribution of MySQL in a non-standard location. Modify it to cd into the proper directory before it runs mysqld_safe. If you do this, your modified version of mysql.server may be overwritten if you upgrade MySQL in the future, so you should make a copy of your edited version that you can reinstall.)

mysql.server stop stops the server by sending a signal to it. You can also stop the server manually by executing mysqladmin shutdown.

To start and stop MySQL automatically on your server, you need to add start and stop commands to the appropriate places in your /etc/rc* files.

If you use the Linux server RPM package (MySQL-server-VERSION.rpm), the mysql.server script is installed in the/etc/init.d directory with the name mysql. You need not install it manually. 

Some vendors provide RPM packages that install a startup script under a different name such as mysqld.

If you install MySQL from a source distribution or using a binary distribution format that does not installmysql.server automatically, you can install it manually. The script can be found in the support-files directory under the MySQL installation directory or in a MySQL source tree.

To install mysql.server manually, copy it to the /etc/init.d directory with the name mysql, and then make it executable. Do this by changing location into the appropriate directory where mysql.server is located and executing these commands:

shell> cp mysql.server /etc/init.d/mysql
shell> chmod +x /etc/init.d/mysql

Older Red Hat systems use the /etc/rc.d/init.d directory rather than /etc/init.d. Adjust the preceding commands accordingly. Alternatively, first create /etc/init.d as a symbolic link that points to /etc/rc.d/init.d:

shell> cd /etc
shell> ln -s rc.d/init.d .

After installing the script, the commands needed to activate it to run at system startup depend on your operating system. On Linux, you can use chkconfig:

shell> chkconfig --add mysql 

On some Linux systems, the following command also seems to be necessary to fully enable the mysql script:

shell> chkconfig --level 345 mysql on 

On FreeBSD, startup scripts generally should go in /usr/local/etc/rc.d/. The rc(8) manual page states that scripts in this directory are executed only if their basename matches the *.sh shell filename pattern. Any other files or directories present within the directory are silently ignored. In other words, on FreeBSD, you should install the mysql.server script as /usr/local/etc/rc.d/ to enable automatic startup.

As an alternative to the preceding setup, some operating systems also use /etc/rc.local or/etc/init.d/boot.local to start additional services on startup. To start up MySQL using this method, you could append a command like the one following to the appropriate startup file:

/bin/sh -c 'cd /usr/local/mysql; ./bin/mysqld_safe --user=mysql &'

For other systems, consult your operating system documentation to see how to install startup scripts.

You can add options for mysql.server in a global /etc/my.cnf file. A typical /etc/my.cnf file might look like this:



The mysql.server script understands the following options: basedirdatadir, and pid-file. If specified, they mustbe placed in an option file, not on the command line. mysql.server understands only start and stop as command-line arguments.

The following table shows which option groups the server and each startup script read from option files:

ScriptOption Groups

[mysqld-major_version] means that groups with names like [mysqld-5.0] and [mysqld-5.1] are read by servers having versions 5.0.x, 5.1.x, and so forth. This feature can be used to specify options that can be read only by servers within a given release series.

For backward compatibility, mysql.server also reads the [mysql_server] group and mysqld_safe also reads the[safe_mysqld] group. However, you should update your option files to use the [mysql.server] and [mysqld_safe]groups instead when using MySQL 5.1.

Keywords: MySQL, Linux, Daemon, Services, Start Automatically

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