MYSQLD_MULTI(1) | MariaDB Database System | MYSQLD_MULTI(1) |
mysqld_multi - manage multiple MariaDB servers
mysqld_multi [options] {start|stop|report} [GNR[,GNR] ...]
mysqld_multi is designed to manage several mysqld processes that listen for connections on different Unix socket files and TCP/IP ports. It can start or stop servers, or report their current status.
mysqld_multi searches for groups named [mysqldN] in my.cnf (or in the file named by the --config-file option). N can be any positive integer. This number is referred to in the following discussion as the option group number, or GNR. Group numbers distinguish option groups from one another and are used as arguments to mysqld_multi to specify which servers you want to start, stop, or obtain a status report for. Options listed in these groups are the same that you would use in the [mysqld] group used for starting mysqld. However, when using multiple servers, it is necessary that each one use its own value for options such as the Unix socket file and TCP/IP port number.
To invoke mysqld_multi, use the following syntax:
shell> mysqld_multi [options] {start|stop|report} [GNR[,GNR] ...]
start, stop, and report indicate which operation to perform. You can perform the designated operation for a single server or multiple servers, depending on the GNR list that follows the option name. If there is no list, mysqld_multi performs the operation for all servers in the option file.
Each GNR value represents an option group number or range of group numbers. The value should be the number at the end of the group name in the option file. For example, the GNR for a group named [mysqld17] is 17. To specify a range of numbers, separate the first and last numbers by a dash. The GNR value 10-13 represents groups [mysqld10] through [mysqld13]. Multiple groups or group ranges can be specified on the command line, separated by commas. There must be no whitespace characters (spaces or tabs) in the GNR list; anything after a whitespace character is ignored.
This command starts a single server using option group [mysqld17]:
shell> mysqld_multi start 17
This command stops several servers, using option groups [mysqld8] and [mysqld10] through [mysqld13]:
shell> mysqld_multi stop 8,10-13
For an example of how you might set up an option file, use this command:
shell> mysqld_multi --example
mysqld_multi searches for option files as follows:
Option files read are searched for [mysqld_multi] and [mysqldN] option groups. The [mysqld_multi] group can be used for options to mysqld_multi itself. [mysqldN] groups can be used for options passed to specific mysqld instances.
The [mysqld] or [mysqld_safe] groups can be used for common options read by all instances of mysqld or mysqld_safe. You can specify a --defaults-file=file_name option to use a different configuration file for that instance, in which case the [mysqld] or [mysqld_safe] groups from that file will be used for that instance.
mysqld_multi supports the following options.
Display a help message and exit.
Display a sample option file.
Specify the name of the log file. If the file exists, log output is appended to it.
The mysqladmin binary to be used to stop servers.
The mysqld binary to be used. Note that you can specify mysqld_safe as the value for this option also. If you use mysqld_safe to start the server, you can include the mysqld or ledir options in the corresponding [mysqldN] option group. These options indicate the name of the server that mysqld_safe should start and the path name of the directory where the server is located. (See the descriptions for these options in mysqld_safe(1).) Example:
[mysqld38] mysqld = mysqld-debug ledir = /opt/local/mysql/libexec
Print log information to stdout rather than to the log file. By default, output goes to the log file.
The password of the MariaDB account to use when invoking mysqladmin. Note that the password value is not optional for this option, unlike for other MariaDB programs.
Silent mode; disable warnings.
Connect to the MariaDB server(s) via the TCP/IP port instead of the UNIX socket. This affects stopping and reporting. If a socket file is missing, the server may still be running, but can be accessed only via the TCP/IP port. By default connecting is done via the UNIX socket. This option affects stop and report operations.
The user name of the MariaDB account to use when invoking mysqladmin.
Be more verbose.
Display version information and exit.
Bootstrap a cluster.
Some notes about mysqld_multi:
shell> mysql -u root -S /tmp/mysql.sock -p Enter password: mysql> GRANT SHUTDOWN ON *.*
-> TO ´multi_admin´@´localhost´ IDENTIFIED BY ´multipass´;
Change the connection parameters appropriately when connecting to each one. Note that the host name part of the account name must allow you to connect as multi_admin from the host where you want to run mysqld_multi.
---------------------------------------------------------------- MY_PWD=`pwd` # Check if we are starting this relative (for the binary release) if test -d $MY_PWD/data/mysql -a \
-f ./share/mysql/english/errmsg.sys -a \
-x ./bin/mysqld ----------------------------------------------------------------
The test performed by these lines should be successful, or you might encounter problems. See mysqld_safe(1).
The following example shows how you might set up an option file for use with mysqld_multi. The order in which the mysqld programs are started or stopped depends on the order in which they appear in the option file. Group numbers need not form an unbroken sequence. The first and fifth [mysqldN] groups were intentionally omitted from the example to illustrate that you can have “gaps” in the option file. This gives you more flexibility.
# This file should probably be in your home dir (~/.my.cnf) # or /etc/my.cnf # Version 2.1 by Jani Tolonen [mysqld_multi] mysqld = /usr/local/bin/mysqld_safe mysqladmin = /usr/local/bin/mysqladmin user = multi_admin password = multipass [mysqld2] socket = /tmp/mysql.sock2 port = 3307 pid-file = /usr/local/mysql/var2/hostname.pid2 datadir = /usr/local/mysql/var2 language = /usr/local/share/mysql/english user = john [mysqld3] socket = /tmp/mysql.sock3 port = 3308 pid-file = /usr/local/mysql/var3/hostname.pid3 datadir = /usr/local/mysql/var3 language = /usr/local/share/mysql/swedish user = monty [mysqld4] socket = /tmp/mysql.sock4 port = 3309 pid-file = /usr/local/mysql/var4/hostname.pid4 datadir = /usr/local/mysql/var4 language = /usr/local/share/mysql/estonia user = tonu [mysqld6] socket = /tmp/mysql.sock6 port = 3311 pid-file = /usr/local/mysql/var6/hostname.pid6 datadir = /usr/local/mysql/var6 language = /usr/local/share/mysql/japanese user = jani
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9 May 2017 | MariaDB 10.3 |