mysqld_safe

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.

           Note
           For some Linux platforms, MySQL installation from RPM or Debian
           packages includes systemd support for managing MySQL server startup
           and shutdown. On these platforms, mysqld_safe is not installed
           because it is unnecessary. For more information, see
           Section 2.5.10, "Managing MySQL Server with systemd".

       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 4.2.2.2, "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 finds and uses 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 accepts options on the command line and in option files, as
       described in the following table. For information about option files
       used by MySQL programs, see Section 4.2.2.2, "Using Option Files".

       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 exits 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 and other option-file
           options, see Section 4.2.2.3, "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 exits
           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 and other option-file
           options, see Section 4.2.2.3, "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 5.7.17, this option is accepted only on the command
           line, not in option files. On platforms that use systemd, the value
           can be specified in the value of MYSQLD_OPTS. See Section 2.5.10,
           "Managing MySQL Server with systemd".

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

       o   --mysqld-safe-log-timestamps This option controls the format for
           timestamps in log output produced by mysqld_safe. The following
           list describes the permitted values. For any other value,
           mysqld_safe logs a warning and uses UTC format.

           o   UTC, utc

               ISO 8601 UTC format (same as --log_timestamps=UTC for the
               server). This is the default.

           o   SYSTEM, system

               ISO 8601 local time format (same as --log_timestamps=SYSTEM for
               the server).

           o   HYPHEN, hyphen

               YY-MM-DD h:mm:ss format, as in mysqld_safe for MySQL 5.6.

           o   LEGACY, legacy

               YYMMDD hh:mm:ss format, as in mysqld_safe prior to MySQL 5.6.

           This option was added in MySQL 5.7.11.

       o   --malloc-lib=[lib_name] The name of the library to use for memory
           allocation instead of the system malloc() library. As of MySQL
           5.7.15, 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 5.7.15, 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 5.7. It is possible for the shortcut form not to
           work under certain configurations, in which case you should specify
           a path name instead.

               Note
               As of MySQL 5.7.13, 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   Prior to MySQL 5.7.31, 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.

               As of MySQL 5.7.31, tcmalloc is not a permitted value for the
               --malloc-lib option.

           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.

               Note
               On systems that manage the server using systemd, mysqld_safe is
               not available. Instead, specify the allocation library by
               setting LD_PRELOAD in /etc/sysconfig/mysql.
           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 5.7.15, this option is accepted only on the command
           line, not in option files. On platforms that use systemd, the value
           can be specified in the value of MYSQLD_OPTS. See Section 2.5.10,
           "Managing MySQL Server with systemd".

       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 5.7.15, this option is accepted only on the command
           line, not in option files. On platforms that use systemd, the value
           can be specified in the value of MYSQLD_OPTS. See Section 2.5.10,
           "Managing MySQL Server with systemd".

       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 and other option-file
           options, see Section 4.2.2.3, "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.

           From MySQL 5.7.2 to 5.7.17, mysqld_safe has its own process ID
           file, which is always named mysqld_safe.pid and located in the
           MySQL data directory.

       o   --plugin-dir=dir_name The path name of the plugin directory.

       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 operating 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 for error logging, the daemon.err
           facility/severity is used for all log messages.

           Using these options to control mysqld logging is deprecated as of
           MySQL 5.7.5. Use the server log_syslog system variable instead. To
           control the facility, use the server log_syslog_facility system
           variable. See Section 5.4.2.3, "Error Logging to the System Log".

       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.

           Using this option to control mysqld logging is deprecated as of
           MySQL 5.7.5. Use the server log_syslog_tag system variable instead.
           See Section 5.4.2.3, "Error Logging to the System Log".

       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 is not used.
       For example, this command does 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 2.1.5,
       "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.

       mysqld_safe tries to use the sleep and date system utilities to
       determine how many times per second it has attempted to start. If these
       utilities are present and the attempted starts per second is greater
       than 5, mysqld_safe waits 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.

       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.

           Note
           Controlling mysqld logging from mysqld_safe is deprecated as of
           MySQL 5.7.5. Use the server's native syslog support instead. For
           more information, see Section 5.4.2.3, "Error Logging to the System
           Log".

COPYRIGHT
       Copyright (C) 1997, 2020, Oracle and/or its affiliates.

       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 5.7                         12/10/2020                    MYSQLD_SAFE(1)
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