4.3. Running MySQL
Most
people run their database servers all of the time. After all, it
makes no sense to have a database if you cannot get to the data. TcX
created MySQL with this in mind and thus MySQL runs as a daemon
process under Unix or as a service under Windows NT. Windows 9x has
only the rough analog of sticking a shortcut to the executable in the
StartUp folder. One important issue to note
under Windows 95 specifically is that Windows 95 leaks
about 200 bytes of main memory for each thread creation. You
therefore do not want to leave MySQL running under Windows 95 for
extended periods of time. This problem does not apply to Windows 98
or Windows NT.
You run MySQL using the
/usr/local/bin/safe_mysqld by default. This
script is a Bourne script you can edit in order
to change any of the default values. Any options that you supply to
safe_mysqld will be passed on to the MySQL
daemon itself.
MySQL is a forking daemon. As soon as you launch it,
the program creates a copy of itself (forks itself) and runs as a
background process. You thus do not need to do anything special to
get MySQL to run in the background. If you use the wrapper
safe_mysqld to start MySQL, then you do need to
put it in the background:
/usr/local/mysql/bin/safe_mysqld &
The reason you need to run safe_mysqld in the
background -- and the reason you should run it instead of directly
running mysqld -- is that the
safe_mysqld script starts
mysqld and then continuously verifies that
mysqld stays running. If MySQL dies
unexpectedly, safe_mysqld will restart it.
Now that you know how to start
MySQL, you need to get MySQL to
start up and shut down with the computer on which it runs. Under
Windows NT, of course, installing MySQL as a service is sufficient
for the task. Under Windows 9x, you have to stick a shortcut to the
MySQL startup script in the StartUp folder. As
with just about everything else in the Unix world, getting MySQL to
run at system startup and shut down at system shutdown is more
complicated. Unix systems generally look for
startup
scripts somewhere under the
/etc
directory -- some
under /etc/rc.d or
/etc/init.d. You should check with your system
administrator or system documentation for the exact details of where
your startup/shutdown script should go. The MySQL distribution comes
with a file in the support_files directory
called mysql.server. This Unix shell script will
serve as your startup/shutdown script.
 |  |  | | 4.2. Installing MySQL |  | 4.4. Database Administration |
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