在FreeBSD下安装mysql5的注意点

FreeBSD 4.x or newer is recommended for running MySQL, because the thread package is much more integrated. To get a secure and stable system, you should use only FreeBSD kernels that are marked -RELEASE .

The easiest (and preferred) way to install MySQL is to use the mysql-server and mysql-client ports available at http://www.freebsd.org/ . Using these ports gives you the following benefits:

A working MySQL with all optimizations enabled that are known to work on your version of FreeBSD.
Automatic configuration and build.
Startup scripts installed in /usr/local/etc/rc.d .
The ability to use pkg_info -L to see which files are installed.
The ability to use pkg_delete to remove MySQL if you no longer want it on your machine.

It is recommended you use MIT-pthreads on FreeBSD 2.x, and native threads on Versions 3 and up. It is possible to run with native threads on some late 2.2.x versions, but you may encounter problems shutting down mysqld .

Unfortunately, certain function calls on FreeBSD are not yet fully thread-safe. Most notably, this includes the gethostbyname() function, which is used by MySQL to convert hostnames into IP addresses. Under certain circumstances, the mysqld process suddenly causes 100% CPU load and is unresponsive. If you encounter this problem, try to start MySQL using the --skip-name-resolve option.

Alternatively, you can link MySQL on FreeBSD 4.x against the LinuxThreads library, which avoids a few of the problems that the native FreeBSD thread implementation has. For a very good comparison of LinuxThreads versus native threads, see Jeremy Zawodny's article FreeBSD or Linux for your MySQL Server? at http://jeremy.zawodny.com/blog/archives/000697.html .

Known problem when using LinuxThreads on FreeBSD is:

The connection times ( wait_timeout , interactive_timeout and net_read_timeout ) values are not honored. The symptom is that persistent connections can hang for a very long time without getting closed down and that a 'kill' for a thread will not take affect until the thread does it a new command

This is probably a signal handling problem in the thread library where the signal doesn't break a pending read. This is supposed to be fixed in FreeBSD 5.0

The MySQL build process requires GNU make ( gmake ) to work. If GNU make is not available, you must install it first before compiling MySQL.

The recommended way to compile and install MySQL on FreeBSD with gcc (2.95.2 and up) is:

CC=gcc CFLAGS="-O2 -fno-strength-reduce"     CXX=gcc CXXFLAGS="-O2 -fno-rtti -fno-exceptions     -felide-constructors -fno-strength-reduce"     ./configure --prefix=/usr/local/mysql --enable-assembler
gmake
gmake install
cd /usr/local/mysql
bin/mysql_install_db --user=mysql
bin/mysqld_safe &amp;

If you notice that configure uses MIT-pthreads, you should read the MIT-pthreads notes.

If you get an error from make install that it can't find /usr/include/pthreads , configure didn't detect that you need MIT-pthreads. To fix this problem, remove config.cache , then re-run configure with the --with-mit-threads option.

Be sure that your name resolver setup is correct. Otherwise, you may experience resolver delays or failures when connecting to mysqld . Also make sure that the localhost entry in the /etc/hosts file is correct. The file should start with a line similar to this:

127.0.0.1       localhost localhost.your.domain

FreeBSD is known to have a very low default file handle limit. Start the server by using the --open-files-limit option for mysqld_safe , or raise the limits for the mysqld user in /etc/login.conf and rebuild it with cap_mkdb /etc/login.conf . Also be sure that you set the appropriate class for this user in the password file if you are not using the default (use chpass mysqld-user-name ).

If you have a lot of memory, you should consider rebuilding the kernel to allow MySQL to use more than 512MB of RAM. Take a look at option MAXDSIZ in the LINT config file for more information.

If you get problems with the current date in MySQL, setting the TZ variable should help.