MYSQLD_SAFE(1)		     MySQL Database System		MYSQLD_SAFE(1)



NAME
       mysqld_safe - MySQL server startup script

SYNOPSIS
       mysqld_safe options

DESCRIPTION
       mysqld_safe is the recommended way to start a mysqld server on Unix.
       mysqld_safe adds some safety features such as restarting the server
       when an error occurs and logging runtime information to an error log. A
       description of error logging is given later in this section.

       mysqld_safe tries to start an executable named mysqld. To override the
       default behavior and specify explicitly the name of the server you want
       to run, specify a --mysqld or --mysqld-version option to mysqld_safe.
       You can also use --ledir to indicate the directory where mysqld_safe
       should look for the server.

       Many of the options to mysqld_safe are the same as the options to
       mysqld. See Section 5.1.6, "Server Command Options".

       Options unknown to mysqld_safe are passed to mysqld if they are
       specified on the command line, but ignored if they are specified in the
       [mysqld_safe] group of an option file. See Section 4.2.6, "Using Option
       Files".

       mysqld_safe reads all options from the [mysqld], [server], and
       [mysqld_safe] sections in option files. For example, if you specify a
       [mysqld] section like this, mysqld_safe will find and use the
       --log-error option:

	   [mysqld]
	   log-error=error.log

       For backward compatibility, mysqld_safe also reads [safe_mysqld]
       sections, but to be current you should rename such sections to
       [mysqld_safe].

       mysqld_safe supports the following options. It also reads option files
       and supports the options for processing them described at
       Section 4.2.7, "Command-Line Options that Affect Option-File Handling".

       o   --help

	   Display a help message and exit.

       o   --basedir=dir_name

	   The path to the MySQL installation directory.

       o   --core-file-size=size

	   The size of the core file that mysqld should be able to create. The
	   option value is passed to ulimit -c.

       o   --datadir=dir_name

	   The path to the data directory.

       o   --defaults-extra-file=file_name

	   Read this option file in addition to the usual option files. If the
	   file does not exist or is otherwise inaccessible, the server will
	   exit with an error.	file_name is interpreted relative to the
	   current directory if given as a relative path name rather than a
	   full path name. This must be the first option on the command line
	   if it is used.

	   For additional information about this option, see Section 4.2.7,
	   "Command-Line Options that Affect Option-File Handling".

       o   --defaults-file=file_name

	   Use only the given option file. If the file does not exist or is
	   otherwise inaccessible, the server will exit with an error.
	   file_name is interpreted relative to the current directory if given
	   as a relative path name rather than a full path name. This must be
	   the first option on the command line if it is used.

	   For additional information about this option, see Section 4.2.7,
	   "Command-Line Options that Affect Option-File Handling".

       o   --ledir=dir_name

	   If mysqld_safe cannot find the server, use this option to indicate
	   the path name to the directory where the server is located.

	   As of MySQL 5.5.54, this option is accepted only on the command
	   line, not in option files.

       o   --log-error=file_name

	   Write the error log to the given file. See Section 5.4.2, "The
	   Error Log".

       o   --malloc-lib=[lib_name] The name of the library to use for memory
	   allocation instead of the system malloc() library. As of MySQL
	   5.5.52, the option value must be one of the directories /usr/lib,
	   /usr/lib64, /usr/lib/i386-linux-gnu, or /usr/lib/x86_64-linux-gnu.
	   Prior to MySQL 5.5.52, any library can be used by specifying its
	   path name, but there is a shortcut form to enable use of the
	   tcmalloc library that is shipped with binary MySQL distributions
	   for Linux in MySQL 5.5. It is possible that the shortcut form will
	   not work under certain configurations, in which case you should
	   specify a path name instead.

	       Note
	       As of MySQL 5.5.50, MySQL distributions no longer include a
	       tcmalloc library.
	   The --malloc-lib option works by modifying the LD_PRELOAD
	   environment value to affect dynamic linking to enable the loader to
	   find the memory-allocation library when mysqld runs:

	   o   If the option is not given, or is given without a value
	       (--malloc-lib=), LD_PRELOAD is not modified and no attempt is
	       made to use tcmalloc.

	   o   If the option is given as --malloc-lib=tcmalloc, mysqld_safe
	       looks for a tcmalloc library in /usr/lib and then in the MySQL
	       pkglibdir location (for example, /usr/local/mysql/lib or
	       whatever is appropriate). If tmalloc is found, its path name is
	       added to the beginning of the LD_PRELOAD value for mysqld. If
	       tcmalloc is not found, mysqld_safe aborts with an error.

	   o   If the option is given as --malloc-lib=/path/to/some/library,
	       that full path is added to the beginning of the LD_PRELOAD
	       value. If the full path points to a nonexistent or unreadable
	       file, mysqld_safe aborts with an error.

	   o   For cases where mysqld_safe adds a path name to LD_PRELOAD, it
	       adds the path to the beginning of any existing value the
	       variable already has.

	   Linux users can use the libtcmalloc_minimal.so included in binary
	   packages by adding these lines to the my.cnf file:

	       [mysqld_safe]
	       malloc-lib=tcmalloc

	   Those lines also suffice for users on any platform who have
	   installed a tcmalloc package in /usr/lib. To use a specific
	   tcmalloc library, specify its full path name. Example:

	       [mysqld_safe]
	       malloc-lib=/opt/lib/libtcmalloc_minimal.so

       o   --mysqld=prog_name

	   The name of the server program (in the ledir directory) that you
	   want to start. This option is needed if you use the MySQL binary
	   distribution but have the data directory outside of the binary
	   distribution. If mysqld_safe cannot find the server, use the
	   --ledir option to indicate the path name to the directory where the
	   server is located.

	   As of MySQL 5.5.52, this option is accepted only on the command
	   line, not in option files.

       o   --mysqld-version=suffix

	   This option is similar to the --mysqld option, but you specify only
	   the suffix for the server program name. The base name is assumed to
	   be mysqld. For example, if you use --mysqld-version=debug,
	   mysqld_safe starts the mysqld-debug program in the ledir directory.
	   If the argument to --mysqld-version is empty, mysqld_safe uses
	   mysqld in the ledir directory.

	   As of MySQL 5.5.52, this option is accepted only on the command
	   line, not in option files.

       o   --nice=priority

	   Use the nice program to set the server's scheduling priority to the
	   given value.

       o   --no-defaults

	   Do not read any option files. If program startup fails due to
	   reading unknown options from an option file, --no-defaults can be
	   used to prevent them from being read. This must be the first option
	   on the command line if it is used.

	   For additional information about this option, see Section 4.2.7,
	   "Command-Line Options that Affect Option-File Handling".

       o   --open-files-limit=count

	   The number of files that mysqld should be able to open. The option
	   value is passed to ulimit -n.

	       Note
	       You must start mysqld_safe as root for this to function
	       properly.

       o   --pid-file=file_name

	   The path name that mysqld should use for its process ID file.

       o   --plugin-dir=dir_name

	   The path name of the plugin directory. This option was added in
	   MySQL 5.5.3.

       o   --port=port_num

	   The port number that the server should use when listening for
	   TCP/IP connections. The port number must be 1024 or higher unless
	   the server is started by the root system user.

       o   --skip-kill-mysqld

	   Do not try to kill stray mysqld processes at startup. This option
	   works only on Linux.

       o   --socket=path

	   The Unix socket file that the server should use when listening for
	   local connections.

       o   --syslog, --skip-syslog

	   --syslog causes error messages to be sent to syslog on systems that
	   support the logger program.	--skip-syslog suppresses the use of
	   syslog; messages are written to an error log file.

	   When syslog is used, the daemon.err syslog facility/severity is
	   used for all log messages.

	   mysqld_safe ignores --syslog if --log-error is also given.

       o   --syslog-tag=tag

	   For logging to syslog, messages from mysqld_safe and mysqld are
	   written with identifiers of mysqld_safe and mysqld, respectively.
	   To specify a suffix for the identifiers, use --syslog-tag=tag,
	   which modifies the identifiers to be mysqld_safe-tag and
	   mysqld-tag.

       o   --timezone=timezone

	   Set the TZ time zone environment variable to the given option
	   value. Consult your operating system documentation for legal time
	   zone specification formats.

       o   --user={user_name|user_id}

	   Run the mysqld server as the user having the name user_name or the
	   numeric user ID user_id. ("User" in this context refers to a system
	   login account, not a MySQL user listed in the grant tables.)

       If you execute mysqld_safe with the --defaults-file or
       --defaults-extra-file option to name an option file, the option must be
       the first one given on the command line or the option file will not be
       used. For example, this command will not use the named option file:

	   mysql> mysqld_safe --port=port_num --defaults-file=file_name

       Instead, use the following command:

	   mysql> mysqld_safe --defaults-file=file_name --port=port_num

       The mysqld_safe script is written so that it normally can start a
       server that was installed from either a source or a binary distribution
       of MySQL, even though these types of distributions typically install
       the server in slightly different locations. (See Section 2.1.4,
       "Installation Layouts".)	 mysqld_safe expects one of the following
       conditions to be true:

       o   The server and databases can be found relative to the working
	   directory (the directory from which mysqld_safe is invoked). For
	   binary distributions, mysqld_safe looks under its working directory
	   for bin and data directories. For source distributions, it looks
	   for libexec and var directories. This condition should be met if
	   you execute mysqld_safe from your MySQL installation directory (for
	   example, /usr/local/mysql for a binary distribution).

       o   If the server and databases cannot be found relative to the working
	   directory, mysqld_safe attempts to locate them by absolute path
	   names. Typical locations are /usr/local/libexec and /usr/local/var.
	   The actual locations are determined from the values configured into
	   the distribution at the time it was built. They should be correct
	   if MySQL is installed in the location specified at configuration
	   time.

       Because mysqld_safe tries to find the server and databases relative to
       its own working directory, you can install a binary distribution of
       MySQL anywhere, as long as you run mysqld_safe from the MySQL
       installation directory:

	   shell> cd mysql_installation_directory
	   shell> bin/mysqld_safe &

       If mysqld_safe fails, even when invoked from the MySQL installation
       directory, specify the --ledir and --datadir options to indicate the
       directories in which the server and databases are located on your
       system.

       Beginning with MySQL 5.5.21, mysqld_safe tries to use the sleep and
       date system utilities to determine how many times it has attempted to
       start this second, and--if these are present and this is greater than 5
       times--is forced to wait 1 full second before starting again. This is
       intended to prevent excessive CPU usage in the event of repeated
       failures. (Bug #11761530, Bug #54035)

       When you use mysqld_safe to start mysqld, mysqld_safe arranges for
       error (and notice) messages from itself and from mysqld to go to the
       same destination.

       There are several mysqld_safe options for controlling the destination
       of these messages:

       o   --log-error=file_name: Write error messages to the named error
	   file.

       o   --syslog: Write error messages to syslog on systems that support
	   the logger program.

       o   --skip-syslog: Do not write error messages to syslog. Messages are
	   written to the default error log file (host_name.err in the data
	   directory), or to a named file if the --log-error option is given.

       If none of these options is given, the default is --skip-syslog.

       If --log-error and --syslog are both given, a warning is issued and
       --log-error takes precedence.

       When mysqld_safe writes a message, notices go to the logging
       destination (syslog or the error log file) and stdout. Errors go to the
       logging destination and stderr.

       Normally, you should not edit the mysqld_safe script. Instead,
       configure mysqld_safe by using command-line options or options in the
       [mysqld_safe] section of a my.cnf option file. In rare cases, it might
       be necessary to edit mysqld_safe to get it to start the server
       properly. However, if you do this, your modified version of mysqld_safe
       might be overwritten if you upgrade MySQL in the future, so you should
       make a copy of your edited version that you can reinstall.

COPYRIGHT
       Copyright (C) 1997, 2018, Oracle and/or its affiliates. All rights
       reserved.

       This documentation is free software; you can redistribute it and/or
       modify it only under the terms of the GNU General Public License as
       published by the Free Software Foundation; version 2 of the License.

       This documentation is distributed in the hope that it will be useful,
       but WITHOUT ANY WARRANTY; without even the implied warranty of
       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
       General Public License for more details.

       You should have received a copy of the GNU General Public License along
       with the program; if not, write to the Free Software Foundation, Inc.,
       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see
       http://www.gnu.org/licenses/.


SEE ALSO
       For more information, please refer to the MySQL Reference Manual, which
       may already be installed locally and which is also available online at
       http://dev.mysql.com/doc/.

AUTHOR
       Oracle Corporation (http://dev.mysql.com/).



MySQL 5.5			  08/28/2018			MYSQLD_SAFE(1)