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2.12.4.1. FreeBSD Notes

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 https://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 FreeBSD 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 https://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 &

If you notice that configure uses MIT-pthreads, you should read the MIT-pthreads notes. See Section 2.8.5, “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, and 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. See Section A.2.17, “File Not Found”. 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). See Section 5.3.1, “mysqld_safe — MySQL Server Startup Script”.

FreeBSD limits the size of a process to 512MB, even if you have much more RAM available on the system. So you may get an error such as this:

Out of memory (Needed 16391 bytes)

In current versions of FreeBSD (at least 4.x and greater), you may increase this limit by adding the following entries to the /boot/loader.conf file and rebooting the machine (these are not settings that can be changed at run time with the sysctl command):

kern.maxdsiz="1073741824" # 1GB
kern.dfldsiz="1073741824" # 1GB
kern.maxssiz="134217728" # 128MB

For older versions of FreeBSD, you must recompile your kernel to change the maximum data segment size for a process. In this case, you should look at the MAXDSIZ option in the LINT config file for more information.

If you get problems with the current date in MySQL, setting the TZ variable should help. See Appendix F, Environment Variables.


 
 
  Published under the terms of the GNU General Public License Design by Interspire