MYSQLMANAGER(1) MySQL Database System MYSQLMANAGER(1)NAMEmysqlmanager - the MySQL Instance Manager
SYNOPSISmysqlmanager [options]
DESCRIPTIONmysqlmanager is the MySQL Instance Manager (IM). This program is a
daemon running on a TCP/IP port that serves to monitor and manage MySQL
Database Server instances. MySQL Instance Manager is available for
Unix-like operating systems, and also on Windows as of MySQL 5.0.13.
MySQL Instance Manager is included in MySQL distributions from version
5.0.3, and can be used in place of the mysqld_safe script to start and
stop the MySQL Server, even from a remote host. MySQL Instance Manager
also implements the functionality (and most of the syntax) of the
mysqld_multi script. A more detailed description of MySQL Instance
Manager follows.
STARTING THE MYSQL SERVER WITH MYSQL INSTANCE MANAGER
Normally, the mysqld MySQL Database Server is started with the
mysql.server script, which usually resides in the /etc/init.d/ folder.
In MySQL 5.0.3 this script invokes mysqlmanager (the MySQL Instance
Manager binary) to start MySQL. (In prior versions of MySQL the
mysqld_safe script is used for this purpose.) Starting from MySQL 5.0.4
the behavior of the init script was changed again to incorporate both
setup schemes. In version 5.0.4, the init startup script uses the old
scheme (invoking mysqld_safe) by default, but one can set the
use_mysqld_safe variable in the script to 0 (zero) to use the MySQL
Instance Manager to start a server.
The Instance Manager's behavior in this case depends on the options
given in the MySQL configuration file. If there is no configuration
file, the MySQL Instance Manager creates a server instance named mysqld
and attempts to start it with default (compiled-in) configuration
values. This means that the IM cannot guess the placement of mysqld if
it is not installed in the default location. If you have installed the
MySQL server in a non-standard location, you should use a configuration
file. See Section 1.5, “Installation Layouts”.
If there is a configuration file, the IM reads it to find [mysqld]
sections (for example, [mysqld], [mysqld1], [mysqld2], and so forth).
Each such section specifies an instance. When it starts, the Instance
Manager attempts to start all server instances that it finds. By
default, the Instance Manager stops all server instances when it shuts
down.
Note that there is a special --mysqld-path=path-to-mysqld-binary option
that is recognized only by the IM. Use this variable to let the IM know
where the mysqld binary resides. You should also set basedir and
datadir options for the server.
The typical startup/shutdown cycle for a MySQL server with the MySQL
Instance Manager enabled is as follows:
1. The MySQL Instance Manager is started with /etc/init.d/mysql script.
2. The MySQL Instance Manager starts all instances and monitors them.
3. If a server instance fails the MySQL Instance Manager restarts it.
4. If the MySQL Instance Manager is shut down (for instance with the
/etc/init.d/mysql stop command), all instances are shut down by the
MySQL Instance Manager.
CONNECTING TO THE MYSQL INSTANCE MANAGER AND CREATING USER ACCOUNTS
Communication with the MySQL Instance Manager is handled using the
MySQL client-server protocol. As such, you can connect to the IM using
the standard mysql client program, as well as the MySQL C API. The IM
supports the version of the MySQL client-server protocol used by the
client tools and libraries distributed along with MySQL 4.1 or later.
Instance Manager Users and Passwords
The Instance Manager stores its user information in a password file.
The default name of the password file is /etc/mysqlmanager.passwd.
Password entries have the following format:
petr:*35110DC9B4D8140F5DE667E28C72DD2597B5C848
If there are no entries in the /etc/mysqlmanager.passwd file, you
cannot connect to the Instance Manager.
To generate a new entry, invoke Instance Manager with the --passwd
option. Then the output can be appended to the /etc/mysqlmanager.passwd
file to add a new user. Here is an example:
shell> mysqlmanager--passwd >> /etc/mysqlmanager.passwd
Creating record for new user.
Enter user name: mike
Enter password: password
Re-type password: password
The preceding command causes the following line to be added to
/etc/mysqlmanager.passwd:
mike:*00A51F3F48415C7D4E8908980D443C29C69B60C9
MySQL Server Accounts for Status Monitoring
To monitor server status, the MySQL Instance Manager will attempt to
connect to the MySQL server instance at regular intervals using the
MySQL_Instance_Manager@localhost user account with a password of
check_connection.
You are not required to create a MySQL_Instance_M@localhost user
account in order for the MySQL Instance Manager to monitor server
status, as a login failure is sufficient to identify that the server is
operational. However, if the account does not exist, failed connection
attempts are logged by the server to its general query log (see
Section 10.2, “The General Query Log”).
MYSQL INSTANCE MANAGER COMMAND OPTIONS
The MySQL Instance Manager supports a number of command line options.
For a brief listing, invoke mysqlmanager with the --help option.
mysqlmanager supports the following options:
· --help, -?
Display a help message and exit.
· --bind-address=IP
The IP address to bind to.
· --default-mysqld-path=path
On Unix, the pathname of the MySQL Server binary, if no path was
provided in the instance section. Example:
--default-mysqld-path=/usr/sbin/mysqld
· --defaults-file=file_name
Read Instance Manager and MySQL Server settings from the given file.
All configuration changes by the Instance Manager will be made to
this file. This must be the first option on the command line if it
is used.
· --install
On Windows, install Instance Manager as a Windows service. This
option was added in MySQL 5.0.11.
· --log=file_name
The path to the IM log file. This is used with the --run-as-service
option.
· --monitoring-interval=seconds
The interval in seconds for monitoring instances. The default value
is 20 seconds. Instance Manager tries to connect to each monitored
instance to check whether it is alive/not hanging. In the case of a
failure, IM performs several attempts to restart the instance. The
nonguarded option in the appropriate instance section disables this
behavior for a particular instance.
· --passwd, -P
Prepare an entry for the password file and exit.
· --password-file=file_name
Look for the Instance Manager users and passwords in this file. The
default file is /etc/mysqlmanager.passwd.
· --pid-file=file_name
The process ID file to use. By default, this file is named
mysqlmanager.pid.
· --port=port_num
The TCP/IP port number to use for incoming connections. (The default
port number assigned by IANA is 2273).
· --print-defaults
Print the current defaults and exit. This must be the first option
on the command line if it is used.
· --remove
On Windows, removes Instance Manager as a Windows service. This
assumes that Instance Manager has been run with --install
previously. This option was added in MySQL 5.0.11.
· --run-as-service
Daemonize and start the angel process. The angel process is simple
and unlikely to crash. It will restart the Instance Manager itself
in case of a failure.
· --socket=path
On Unix, the socket file to use for incoming connections. By
default, the file is named /tmp/mysqlmanager.sock.
· --standalone
On Windows, run Instance Manager in standalone mode. This option was
added in MySQL 5.0.13.
· --user=user_name
Username to start and run the mysqlmanager under. It is recommended
to run mysqlmanager under the same user account used to run the
mysqld server. (“User” in this context refers to a system login
account, not a MySQL user listed in the grant tables.)
· --version, -V
Output version information and exit.
· --wait-timeout=N
The number of seconds to wait for activity on a connection befoe
closing it. The default is 28800 seconds (8 hours).
This option was added in MySQL 5.0.19. Before that, the timeout is
30 seconds and cannot be changed.
MYSQL INSTANCE MANAGER CONFIGURATION FILES
Instance Manager uses the standard my.cnf file. It uses the [manager]
section to read options for itself and the [mysqld] sections to create
instances. The [manager] section contains any of the options listed in
the section called “MYSQL INSTANCE MANAGER COMMAND OPTIONS”. Here is an
example [manager] section:
# MySQL Instance Manager options section
[manager]
default-mysqld-path = /usr/local/mysql/libexec/mysqld
socket=/tmp/manager.sock
pid-file=/tmp/manager.pid
password-file = /home/cps/.mysqlmanager.passwd
monitoring-interval = 2
port = 1999
bind-address = 192.168.1.5
Prior to MySQL 5.0.10, the MySQL Instance Manager read the same
configuration files as the MySQL Server, including /etc/my.cnf,
~/.my.cnf, etc. As of MySQL 5.0.10, the MySQL Instance Manager reads
and manages the /etc/my.cnf file only on Unix. On Windows, MySQL
Instance Manager reads the my.ini file in the directory where Instance
Manager is installed. The default option file location can be changed
with the --defaults-file=file_name option.
Instance sections specify options given to each instance at startup.
These are mainly common MySQL server options, but there are some
IM-specific options:
· mysqld-path = path
The pathname to the mysqld server binary.
· shutdown-delay = seconds
The number of seconds IM should wait for the instance to shut down.
The default value is 35 seconds. After the delay expires, the IM
assumes that the instance is hanging and attempts to terminate it.
If you use InnoDB with large tables, you should increase this value.
· nonguarded
This option should be specified if you want to disable IM monitoring
functionality for a certain instance.
Here are some sample instance sections:
[mysqld]
mysqld-path=/usr/local/mysql/libexec/mysqld
socket=/tmp/mysql.sock
port=3307
server_id=1
skip-stack-trace
core-file
skip-bdb
log-bin
log-error
log=mylog
log-slow-queries
[mysqld2]
nonguarded
port=3308
server_id=2
mysqld-path= /home/cps/mysql/trees/mysql-5.0/sql/mysqld
socket = /tmp/mysql.sock5
pid-file = /tmp/hostname.pid5
datadir= /home/cps/mysql_data/data_dir1
language=/home/cps/mysql/trees/mysql-5.0/sql/share/english
log-bin
log=/tmp/fordel.log
COMMANDS RECOGNIZED BY THE MYSQL INSTANCE MANAGER
Once you've set up a password file for the MySQL Instance Manager and
the IM is running, you can connect to it. You can use the mysql client
tool connect through a standard MySQL API. The following list of
commands shows the MySQL Instance Manager currently accepts, with
samples.
· START INSTANCE instance_name
This command attempts to start an instance.
mysql> START INSTANCE mysqld4;
Query OK, 0 rows affected (0,00 sec)
· STOP INSTANCE instance_name
This command attempts to stop an instance.
mysql> STOP INSTANCE mysqld4;
Query OK, 0 rows affected (0,00 sec)
· SHOW INSTANCES
Shows the names of all loaded instances.
mysql> SHOW INSTANCES;
+---------------+---------+
| instance_name | status |
+---------------+---------+
| mysqld3 | offline |
| mysqld4 | online |
| mysqld2 | offline |
+---------------+---------+
3 rows in set (0,04 sec)
· SHOW INSTANCE STATUS instance_name
Shows the status and the version information for an instance.
mysql> SHOW INSTANCE STATUS mysqld3;
+---------------+--------+---------+
| instance_name | status | version |
+---------------+--------+---------+
| mysqld3 | online | unknown |
+---------------+--------+---------+
1 row in set (0.00 sec)
· SHOW INSTANCE OPTIONS instance_name
Shows the options used by an instance.
mysql> SHOW INSTANCE OPTIONS mysqld3;
+---------------+---------------------------------------------------+
| option_name | value |
+---------------+---------------------------------------------------+
| instance_name | mysqld3 |
| mysqld-path | /home/cps/mysql/trees/mysql-4.1/sql/mysqld |
| port | 3309 |
| socket | /tmp/mysql.sock3 |
| pid-file | hostname.pid3 |
| datadir | /home/cps/mysql_data/data_dir1/ |
| language | /home/cps/mysql/trees/mysql-4.1/sql/share/english |
+---------------+---------------------------------------------------+
7 rows in set (0.01 sec)
· SHOW instance_name LOG FILES
The command lists all log files used by the instance. The result set
contains the path to the log file and the log file size. If no log
file path is specified in the configuration file (for example,
log=/var/mysql.log), the Instance Manager tries to guess its
placement. If the IM is unable to guess the logfile placement you
should specify the log file location explicitly by using the
appropriate log option in the instance section of the configuration
file.
mysql> SHOW mysqld LOG FILES;
+-------------+------------------------------------+----------+
| Logfile | Path | Filesize |
+-------------+------------------------------------+----------+
| ERROR LOG | /home/cps/var/mysql/owlet.err | 9186 |
| GENERAL LOG | /home/cps/var/mysql/owlet.log | 471503 |
| SLOW LOG | /home/cps/var/mysql/owlet-slow.log | 4463 |
+-------------+------------------------------------+----------+
3 rows in set (0.01 sec)
· SHOW instance_name LOG {ERROR | SLOW | GENERAL}
size[,offset_from_end]
This command retrieves a portion of the specified log file. Because
most users are interested in the latest log messages, the size
parameter defines the number of bytes you would like to retrieve
starting from the log end. You can retrieve data from the middle of
the log file by specifying the optional offset_from_end parameter.
The following example retrieves 21 bytes of data, starting 23 bytes
from the end of the log file and ending 2 bytes from the end of the
log file:
mysql> SHOW mysqld LOG GENERAL 21, 2;
+---------------------+
| Log |
+---------------------+
| using password: YES |
+---------------------+
1 row in set (0.00 sec)
· SET instance_name.option_name=option_value
This command edits the specified instance's configuration file to
change or add instance options. The IM assumes that the
configuration file is located at /etc/my.cnf. You should check that
the file exists and has appropriate permissions.
mysql> SET mysqld2.port=3322;
Query OK, 0 rows affected (0.00 sec)
Changes made to the configuration file do not take effect until the
MySQL server is restarted. In addition, these changes are not stored
in the instance manager's local cache of instance settings until a
FLUSH INSTANCES command is executed.
· UNSET instance_name.option_name
This command removes an option from an instance's configuration
file.
mysql> UNSET mysqld2.port;
Query OK, 0 rows affected (0.00 sec)
Changes made to the configuration file do not take effect until the
MySQL server is restarted. In addition, these changes are not stored
in the instance manager's local cache of instance settings until a
FLUSH INSTANCES command is executed.
· FLUSH INSTANCES
This command forces IM to reread the configuration file and to
refresh internal structures. This command should be performed after
editing the configuration file. The command does not restart
instances.
mysql> FLUSH INSTANCES;
Query OK, 0 rows affected (0.04 sec)
SEE ALSOmsql2mysql(1), myisamchk(1), myisamlog(1), myisampack(1), mysql(1),
mysql.server(1), mysql_config(1), mysql_fix_privilege_tables(1),
mysql_upgrade(1), mysql_zap(1), mysqlaccess(1), mysqladmin(1),
mysqlbinlog(1), mysqlcheck(1), mysqld(1), mysqld_multi(1),
mysqld_safe(1), mysqldump(1), mysqlhotcopy(1), mysqlimport(1),
mysqlshow(1), perror(1), replace(1), safe_mysqld(1)
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
MySQL AB (http://www.mysql.com/). This software comes with no
warranty.
MySQL 5.0 03/04/2006 MYSQLMANAGER(1)
