1MYSQLD_MULTI(1)             MariaDB Database System            MYSQLD_MULTI(1)
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NAME

6       mysqld_multi - manage multiple MariaDB servers
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SYNOPSIS

9       mysqld_multi [options] {start|stop|report} [GNR[,GNR] ...]
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DESCRIPTION

12       mysqld_multi is designed to manage several mysqld processes that listen
13       for connections on different Unix socket files and TCP/IP ports. It can
14       start or stop servers, or report their current status.
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16       mysqld_multi searches for groups named [mysqldN] in my.cnf (or in the
17       file named by the --config-file option).  N can be any positive
18       integer. This number is referred to in the following discussion as the
19       option group number, or GNR. Group numbers distinguish option groups
20       from one another and are used as arguments to mysqld_multi to specify
21       which servers you want to start, stop, or obtain a status report for.
22       Options listed in these groups are the same that you would use in the
23       [mysqld] group used for starting mysqld. However, when using multiple
24       servers, it is necessary that each one use its own value for options
25       such as the Unix socket file and TCP/IP port number.
26
27       To invoke mysqld_multi, use the following syntax:
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29           shell> mysqld_multi [options] {start|stop|report} [GNR[,GNR] ...]
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31       start, stop, and report indicate which operation to perform. You can
32       perform the designated operation for a single server or multiple
33       servers, depending on the GNR list that follows the option name. If
34       there is no list, mysqld_multi performs the operation for all servers
35       in the option file.
36
37       Each GNR value represents an option group number or range of group
38       numbers. The value should be the number at the end of the group name in
39       the option file. For example, the GNR for a group named [mysqld17] is
40       17. To specify a range of numbers, separate the first and last numbers
41       by a dash. The GNR value 10-13 represents groups [mysqld10] through
42       [mysqld13]. Multiple groups or group ranges can be specified on the
43       command line, separated by commas. There must be no whitespace
44       characters (spaces or tabs) in the GNR list; anything after a
45       whitespace character is ignored.
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47       This command starts a single server using option group [mysqld17]:
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49           shell> mysqld_multi start 17
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51       This command stops several servers, using option groups [mysqld8] and
52       [mysqld10] through [mysqld13]:
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54           shell> mysqld_multi stop 8,10-13
55
56       For an example of how you might set up an option file, use this
57       command:
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59           shell> mysqld_multi --example
60
61       mysqld_multi searches for option files as follows:
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63       •   With --no-defaults, no option files are read.
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65       •   With --defaults-file=file_name, only the named file is read.
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67       •   Otherwise, option files in the standard list of locations are read,
68           including any file named by the --defaults-extra-file=file_name
69           option, if one is given. (If the option is given multiple times,
70           the last value is used.)
71
72       Option files read are searched for [mysqld_multi] and [mysqldN] option
73       groups. The [mysqld_multi] group can be used for options to
74       mysqld_multi itself.  [mysqldN] groups can be used for options passed
75       to specific mysqld instances.
76
77       The [mysqld] or [mysqld_safe] groups can be used for common options
78       read by all instances of mysqld or mysqld_safe. You can specify a
79       --defaults-file=file_name option to use a different configuration file
80       for that instance, in which case the [mysqld] or [mysqld_safe] groups
81       from that file will be used for that instance.
82
83       mysqld_multi supports the following options.
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85--help
86
87           Display a help message and exit.
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89--example
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91           Display a sample option file.
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93--log=file_name
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95           Specify the name of the log file. If the file exists, log output is
96           appended to it.
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98--mysqladmin=prog_name
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100           The mysqladmin binary to be used to stop servers.
101
102--mysqld=prog_name
103
104           The mysqld binary to be used. Note that you can specify mysqld_safe
105           as the value for this option also. If you use mysqld_safe to start
106           the server, you can include the mysqld or ledir options in the
107           corresponding [mysqldN] option group. These options indicate the
108           name of the server that mysqld_safe should start and the path name
109           of the directory where the server is located. (See the descriptions
110           for these options in mysqld_safe(1).) Example:
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112               [mysqld38]
113               mysqld = mysqld-debug
114               ledir  = /opt/local/mysql/libexec
115
116--no-log
117
118           Print log information to stdout rather than to the log file. By
119           default, output goes to the log file.
120
121--password=password
122
123           The password of the MariaDB account to use when invoking
124           mysqladmin. Note that the password value is not optional for this
125           option, unlike for other MariaDB programs.
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127--silent
128
129           Silent mode; disable warnings.
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131--tcp-ip
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133           Connect to the MariaDB server(s) via the TCP/IP port instead of the
134           UNIX socket. This affects stopping and reporting. If a socket file
135           is missing, the server may still be running, but can be accessed
136           only via the TCP/IP port. By default connecting is done via the
137           UNIX socket. This option affects stop and report operations.
138
139--user=user_name
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141           The user name of the MariaDB account to use when invoking
142           mysqladmin.
143
144--verbose
145
146           Be more verbose.
147
148--version
149
150           Display version information and exit.
151
152--wsrep-new-cluster
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154           Bootstrap a cluster.
155
156       Some notes about mysqld_multi:
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158Most important: Before using mysqld_multi be sure that you
159           understand the meanings of the options that are passed to the
160           mysqld servers and why you would want to have separate mysqld
161           processes. Beware of the dangers of using multiple mysqld servers
162           with the same data directory. Use separate data directories, unless
163           you know what you are doing. Starting multiple servers with the
164           same data directory does not give you extra performance in a
165           threaded system.
166
167Important: Make sure that the data directory for each server is
168           fully accessible to the Unix account that the specific mysqld
169           process is started as.  Do not use the Unix root account for this,
170           unless you know what you are doing.
171
172       •   Make sure that the MariaDB account used for stopping the mysqld
173           servers (with the mysqladmin program) has the same user name and
174           password for each server. Also, make sure that the account has the
175           SHUTDOWN privilege. If the servers that you want to manage have
176           different user names or passwords for the administrative accounts,
177           you might want to create an account on each server that has the
178           same user name and password. For example, you might set up a common
179           multi_admin account by executing the following commands for each
180           server:
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182               shell> mysql -u root -S /tmp/mysql.sock -p
183               Enter password:
184               mysql> GRANT SHUTDOWN ON *.*
185                   -> TO ´multi_admin´@´localhost´ IDENTIFIED BY ´multipass´;
186
187           Change the connection parameters appropriately when connecting to
188           each one. Note that the host name part of the account name must
189           allow you to connect as multi_admin from the host where you want to
190           run mysqld_multi.
191
192       •   The Unix socket file and the TCP/IP port number must be different
193           for every mysqld. (Alternatively, if the host has multiple network
194           addresses, you can use --bind-address to cause different servers to
195           listen to different interfaces.)
196
197       •   The --pid-file option is very important if you are using
198           mysqld_safe to start mysqld (for example, --mysqld=mysqld_safe)
199           Every mysqld should have its own process ID file. The advantage of
200           using mysqld_safe instead of mysqld is that mysqld_safe monitors
201           its mysqld process and restarts it if the process terminates due to
202           a signal sent using kill -9 or for other reasons, such as a
203           segmentation fault. Please note that the mysqld_safe script might
204           require that you start it from a certain place. This means that you
205           might have to change location to a certain directory before running
206           mysqld_multi. If you have problems starting, please see the
207           mysqld_safe script. Check especially the lines:
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209               ----------------------------------------------------------------
210               MY_PWD=`pwd`
211               # Check if we are starting this relative (for the binary release)
212               if test -d $MY_PWD/data/mysql -a \
213                  -f ./share/mysql/english/errmsg.sys -a \
214                  -x ./bin/mysqld
215               ----------------------------------------------------------------
216
217           The test performed by these lines should be successful, or you
218           might encounter problems. See mysqld_safe(1).
219
220       •   You might want to use the --user option for mysqld, but to do this
221           you need to run the mysqld_multi script as the Unix root user.
222           Having the option in the option file doesn´t matter; you just get a
223           warning if you are not the superuser and the mysqld processes are
224           started under your own Unix account.
225
226       The following example shows how you might set up an option file for use
227       with mysqld_multi. The order in which the mysqld programs are started
228       or stopped depends on the order in which they appear in the option
229       file. Group numbers need not form an unbroken sequence. The first and
230       fifth [mysqldN] groups were intentionally omitted from the example to
231       illustrate that you can have “gaps” in the option file. This gives you
232       more flexibility.
233
234           # This file should probably be in your home dir (~/.my.cnf)
235           # or /etc/my.cnf
236           # Version 2.1 by Jani Tolonen
237           [mysqld_multi]
238           mysqld     = /usr/local/bin/mysqld_safe
239           mysqladmin = /usr/local/bin/mysqladmin
240           user       = multi_admin
241           password   = multipass
242           [mysqld2]
243           socket     = /tmp/mysql.sock2
244           port       = 3307
245           pid-file   = /usr/local/mysql/var2/hostname.pid2
246           datadir    = /usr/local/mysql/var2
247           language   = /usr/local/share/mysql/english
248           user       = john
249           [mysqld3]
250           socket     = /tmp/mysql.sock3
251           port       = 3308
252           pid-file   = /usr/local/mysql/var3/hostname.pid3
253           datadir    = /usr/local/mysql/var3
254           language   = /usr/local/share/mysql/swedish
255           user       = monty
256           [mysqld4]
257           socket     = /tmp/mysql.sock4
258           port       = 3309
259           pid-file   = /usr/local/mysql/var4/hostname.pid4
260           datadir    = /usr/local/mysql/var4
261           language   = /usr/local/share/mysql/estonia
262           user       = tonu
263           [mysqld6]
264           socket     = /tmp/mysql.sock6
265           port       = 3311
266           pid-file   = /usr/local/mysql/var6/hostname.pid6
267           datadir    = /usr/local/mysql/var6
268           language   = /usr/local/share/mysql/japanese
269           user       = jani
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272       Copyright 2007-2008 MySQL AB, 2008-2010 Sun Microsystems, Inc.,
273       2010-2019 MariaDB Foundation
274
275       This documentation is free software; you can redistribute it and/or
276       modify it only under the terms of the GNU General Public License as
277       published by the Free Software Foundation; version 2 of the License.
278
279       This documentation is distributed in the hope that it will be useful,
280       but WITHOUT ANY WARRANTY; without even the implied warranty of
281       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
282       General Public License for more details.
283
284       You should have received a copy of the GNU General Public License along
285       with the program; if not, write to the Free Software Foundation, Inc.,
286       51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA or see
287       http://www.gnu.org/licenses/.
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289

SEE ALSO

291       For more information, please refer to the MariaDB Knowledge Base,
292       available online at https://mariadb.com/kb/
293

AUTHOR

295       MariaDB Foundation (http://www.mariadb.org/).
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299MariaDB 10.5                     27 June 2019                  MYSQLD_MULTI(1)
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