1MYSQLD_MULTI(1) MySQL Database System MYSQLD_MULTI(1)
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6 mysqld_multi - manage multiple MySQL servers
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9 mysqld_multi [options] {start|stop|report} [GNR[,GNR] ...]
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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. The MySQL
15 Instance Manager is an alternative means of managing multiple servers
16 (see mysqlmanager(8)).
17 mysqld_multi searches for groups named [mysqldN] in my.cnf (or in the
19 file named by the --config-file option). N can be any positive
20 integer. This number is referred to in the following discussion as the
21 option group number, or GNR. Group numbers distinguish option groups
22 from one another and are used as arguments to mysqld_multi to specify
23 which servers you want to start, stop, or obtain a status report for.
24 Options listed in these groups are the same that you would use in the
25 [mysqld] group used for starting mysqld. (See, for example,
26 Section 2.12.1.2, “Starting and Stopping MySQL Automatically”.)
27 However, when using multiple servers, it is necessary that each one use
28 its own value for options such as the Unix socket file and TCP/IP port
29 number. For more information on which options must be unique per server
30 in a multiple-server environment, see Section 5.3, “Running Multiple
31 MySQL Instances on One Machine”.
32 To invoke mysqld_multi, use the following syntax:
34 shell> mysqld_multi [options] {start|stop|report} [GNR[,GNR] ...]
36 start, stop, and report indicate which operation to perform. You can
38 perform the designated operation for a single server or multiple
39 servers, depending on the GNR list that follows the option name. If
40 there is no list, mysqld_multi performs the operation for all servers
41 in the option file.
42 Each GNR value represents an option group number or range of group
44 numbers. The value should be the number at the end of the group name in
45 the option file. For example, the GNR for a group named [mysqld17] is
46 17. To specify a range of numbers, separate the first and last numbers
47 by a dash. The GNR value 10-13 represents groups [mysqld10] through
48 [mysqld13]. Multiple groups or group ranges can be specified on the
49 command line, separated by commas. There must be no whitespace
50 characters (spaces or tabs) in the GNR list; anything after a
51 whitespace character is ignored.
52 This command starts a single server using option group [mysqld17]:
54 shell> mysqld_multi start 17
56 This command stops several servers, using option groups [mysqld8] and
58 [mysqld10] through [mysqld13]:
59 shell> mysqld_multi stop 8,10-13
61 For an example of how you might set up an option file, use this
63 command:
64 shell> mysqld_multi --example
66 As of MySQL 5.1.18, mysqld_multi searches for option files as follows:
68 · With --no-defaults, no option files are read.
70 · With --defaults-file=file_name, only the named file is read.
72 · Otherwise, option files in the standard list of locations are read,
74 including any file named by the --defaults-extra-file=file_name
75 option, if one is given. (If the option is given multiple times,
76 the last value is used.)
77 Before MySQL 5.1.18, the preceding options are not recognized. Files in
79 the standard locations are read, and any file named by the
80 --config-file=file_name option, if one is given. A file named by
81 --config-file is read only for [mysqldN] option groups, not the
82 [mysqld_multi] group.
83 Option files read are searched for [mysqld_multi] and [mysqldN] option
85 groups. The [mysqld_multi] group can be used for options to
86 mysqld_multi itself. [mysqldN] groups can be used for options passed
87 to specific mysqld instances.
88 As of MySQL 5.1.35, the [mysqld] or [mysqld_safe] groups can be used
90 for common options read by all instances of mysqld or mysqld_safe. You
91 can specify a --defaults-file=file_name option to use a different
92 configuration file for that instance, in which case the [mysqld] or
93 [mysqld_safe] groups from that file will be used for that instance.
94 Before MySQL 5.1.35, some versions of mysqld_multi pass the
95 --no-defaults options to instances, so these techniques are
96 inapplicable.
97 mysqld_multi supports the following options.
99 · --help
101 Display a help message and exit.
103 · --config-file=file_name
105 As of MySQL 5.1.18, this option is deprecated. If given, it is
107 treated the same way as --defaults-extra-file, described earlier.
108 --config-file is removed in MySQL 5.5.
109 Before MySQL 5.1.18, this option specifies the name of an extra
111 option file. It affects where mysqld_multi looks for [mysqldN]
112 option groups. Without this option, all options are read from the
113 usual my.cnf file. The option does not affect where mysqld_multi
114 reads its own options, which are always taken from the
115 [mysqld_multi] group in the usual my.cnf file.
116 · --example
118 Display a sample option file.
120 · --log=file_name
122 Specify the name of the log file. If the file exists, log output is
124 appended to it.
125 · --mysqladmin=prog_name
127 The mysqladmin binary to be used to stop servers.
129 · --mysqld=prog_name
131 The mysqld binary to be used. Note that you can specify mysqld_safe
133 as the value for this option also. If you use mysqld_safe to start
134 the server, you can include the mysqld or ledir options in the
135 corresponding [mysqldN] option group. These options indicate the
136 name of the server that mysqld_safe should start and the path name
137 of the directory where the server is located. (See the descriptions
138 for these options in mysqld_safe(1).) Example:
139 [mysqld38]
141 mysqld = mysqld-debug
142 ledir = /opt/local/mysql/libexec
143 · --no-log
145 Print log information to stdout rather than to the log file. By
147 default, output goes to the log file.
148 · --password=password
150 The password of the MySQL account to use when invoking mysqladmin.
152 Note that the password value is not optional for this option,
153 unlike for other MySQL programs.
154 · --silent
156 Silent mode; disable warnings.
158 · --tcp-ip
160 Connect to each MySQL server through the TCP/IP port instead of the
162 Unix socket file. (If a socket file is missing, the server might
163 still be running, but accessible only through the TCP/IP port.) By
164 default, connections are made using the Unix socket file. This
165 option affects stop and report operations.
166 · --user=user_name
168 The user name of the MySQL account to use when invoking mysqladmin.
170 · --verbose
172 Be more verbose.
174 · --version
176 Display version information and exit.
178 Some notes about mysqld_multi:
180 · Most important: Before using mysqld_multi be sure that you
182 understand the meanings of the options that are passed to the
183 mysqld servers and why you would want to have separate mysqld
184 processes. Beware of the dangers of using multiple mysqld servers
185 with the same data directory. Use separate data directories, unless
186 you know what you are doing. Starting multiple servers with the
187 same data directory does not give you extra performance in a
188 threaded system. See Section 5.3, “Running Multiple MySQL Instances
189 on One Machine”.
190 ·
192 Important
194 Make sure that the data directory for each server is fully
195 accessible to the Unix account that the specific mysqld process
196 is started as. Do not use the Unix root account for this,
197 unless you know what you are doing. See Section 6.1.5, “How to
198 Run MySQL as a Normal User”.
199 · Make sure that the MySQL account used for stopping the mysqld
201 servers (with the mysqladmin program) has the same user name and
202 password for each server. Also, make sure that the account has the
203 SHUTDOWN privilege. If the servers that you want to manage have
204 different user names or passwords for the administrative accounts,
205 you might want to create an account on each server that has the
206 same user name and password. For example, you might set up a common
207 multi_admin account by executing the following commands for each
208 server:
209 shell> mysql -u root -S /tmp/mysql.sock -p
211 Enter password:
212 mysql> GRANT SHUTDOWN ON *.*
213 -> TO 'multi_admin'@'localhost' IDENTIFIED BY 'multipass';
214 See Section 6.2, “The MySQL Access Privilege System”. You have to
216 do this for each mysqld server. Change the connection parameters
217 appropriately when connecting to each one. Note that the host name
218 part of the account name must permit you to connect as multi_admin
219 from the host where you want to run mysqld_multi.
220 · The Unix socket file and the TCP/IP port number must be different
222 for every mysqld. (Alternatively, if the host has multiple network
223 addresses, you can use --bind-address to cause different servers to
224 listen to different interfaces.)
225 · The --pid-file option is very important if you are using
227 mysqld_safe to start mysqld (for example, --mysqld=mysqld_safe)
228 Every mysqld should have its own process ID file. The advantage of
229 using mysqld_safe instead of mysqld is that mysqld_safe monitors
230 its mysqld process and restarts it if the process terminates due to
231 a signal sent using kill -9 or for other reasons, such as a
232 segmentation fault. Please note that the mysqld_safe script might
233 require that you start it from a certain place. This means that you
234 might have to change location to a certain directory before running
235 mysqld_multi. If you have problems starting, please see the
236 mysqld_safe script. Check especially the lines:
237 ----------------------------------------------------------------
239 MY_PWD=`pwd`
240 # Check if we are starting this relative (for the binary release)
241 if test -d $MY_PWD/data/mysql -a \
242 -f ./share/mysql/english/errmsg.sys -a \
243 -x ./bin/mysqld
244 ----------------------------------------------------------------
245 The test performed by these lines should be successful, or you
247 might encounter problems. See mysqld_safe(1).
248 · You might want to use the --user option for mysqld, but to do this
250 you need to run the mysqld_multi script as the Unix superuser
251 (root). Having the option in the option file doesn't matter; you
252 just get a warning if you are not the superuser and the mysqld
253 processes are started under your own Unix account.
254 The following example shows how you might set up an option file for use
256 with mysqld_multi. The order in which the mysqld programs are started
257 or stopped depends on the order in which they appear in the option
258 file. Group numbers need not form an unbroken sequence. The first and
259 fifth [mysqldN] groups were intentionally omitted from the example to
260 illustrate that you can have “gaps” in the option file. This gives you
261 more flexibility.
262 # This file should probably be in your home dir (~/.my.cnf)
264 # or /etc/my.cnf
265 # Version 2.1 by Jani Tolonen
266 [mysqld_multi]
267 mysqld = /usr/local/bin/mysqld_safe
268 mysqladmin = /usr/local/bin/mysqladmin
269 user = multi_admin
270 password = multipass
271 [mysqld2]
272 socket = /tmp/mysql.sock2
273 port = 3307
274 pid-file = /usr/local/mysql/var2/hostname.pid2
275 datadir = /usr/local/mysql/var2
276 language = /usr/local/share/mysql/english
277 user = john
278 [mysqld3]
279 socket = /tmp/mysql.sock3
280 port = 3308
281 pid-file = /usr/local/mysql/var3/hostname.pid3
282 datadir = /usr/local/mysql/var3
283 language = /usr/local/share/mysql/swedish
284 user = monty
285 [mysqld4]
286 socket = /tmp/mysql.sock4
287 port = 3309
288 pid-file = /usr/local/mysql/var4/hostname.pid4
289 datadir = /usr/local/mysql/var4
290 language = /usr/local/share/mysql/estonia
291 user = tonu
292 [mysqld6]
293 socket = /tmp/mysql.sock6
294 port = 3311
295 pid-file = /usr/local/mysql/var6/hostname.pid6
296 datadir = /usr/local/mysql/var6
297 language = /usr/local/share/mysql/japanese
298 user = jani
299 See Section 4.2.3.3, “Using Option Files”.
301
303 Copyright © 1997, 2013, Oracle and/or its affiliates. All rights
304 reserved.
305 This documentation is free software; you can redistribute it and/or
307 modify it only under the terms of the GNU General Public License as
308 published by the Free Software Foundation; version 2 of the License.
309 This documentation is distributed in the hope that it will be useful,
311 but WITHOUT ANY WARRANTY; without even the implied warranty of
312 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
313 General Public License for more details.
314 You should have received a copy of the GNU General Public License along
316 with the program; if not, write to the Free Software Foundation, Inc.,
317 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or see
318 http://www.gnu.org/licenses/.
319
322 For more information, please refer to the MySQL Reference Manual, which
323 may already be installed locally and which is also available online at
324 http://dev.mysql.com/doc/.
325
327 Oracle Corporation (http://dev.mysql.com/).
328MySQL 5.1 11/04/2013 MYSQLD_MULTI(1)