Name
mc_ctl - Start and stop Mirroring Controller, switch/disconnect the server, or display the server status.
mc_ctl - Start and stop Mirroring Controller, switch/disconnect the server, display the server status, or register and unregister as a Windows service.
Overview
mc_ctl start [-M mcdir] [-w| -W] [-f| -F] [--mc-only] [--async-connect-arbiter] [--local-server server_id]
mc_ctl stop [-M mcdir] [[-a] [--mc-only]| [-e][--local-server server_id]]
mc_ctl status [-M mcdir] [--arbiter] [--local-server server_id]
mc_ctl switch [-M mcdir] [--force [--no-fencing ]] [--local-server server_id]
mc_ctl detach [-M mcdir] [--no-fencing] [--local-server server_id]
mc_ctl enable-failover [-M mcdir] [--local-server server_id]
mc_ctl disable-failover [-M mcdir] [--local-server server_id]
mc_ctl unregister [-M mcdir] [--local-server server_id]
Description
mc_ctl starts and stops Mirroring Controller, switches/disconnects the server, or displays the server status.
mc_ctl starts and stops Mirroring Controller, switches/disconnects the server, displays the server status, or registers and unregisters as a Windows service.
The start mode starts Mirroring Controller. If the --mc-only option is omitted, the command starts a database instance.
The stop mode stops Mirroring Controller. If the --mc-only option is omitted, the database instance is stopped. If --mc-only option is not specified, database instance is also stopped. When executes on standby server without --mc-only, standby server will be detached from primary server.
The status mode displays the status of the servers, database instance processes, and disks monitored by Mirroring Controller. Additionally, if the --arbiter option is specified, Mirroring Controller arbitration process connection status is displayed.
The switch mode switches the primary server. When the server is switched, the database instance on the primary server stops, and the database instance on the standby server is upgraded to primary server and begins degrading operation. This mode can be executed on the primary server and standby server in an environment where the Mirroring Controller process can communicate with the Mirroring Controller process on the other server.
The detach mode forcibly disconnects the standby server. This mode is used to forcibly disconnect the other server when stopping of Mirroring Controller cannot be performed using stop mode (which requires login to the standby server). It can only be executed on the primary server.
The enable-failover mode enables automatic switching and disconnection.
The disable-failover mode disables automatic switching and disconnection.
The register mode registers Mirroring Controller as a Windows service. The -w, -W, -f, -F, --mc-only, --async-connect-arbiter, and --local-server options are used when Mirroring Controller is started and stopped as a Windows service. If the mc_ctl command is used to start and stop Mirroring Controller, the option specified in the command will be valid.
The unregister mode unregisters Mirroring Controller as a Windows service.
If Mirroring Controller has not been started on the server that executes the command, commands for any mode other than the start mode, and status mode.
Execute this command as an instance administrator.
If Mirroring Controller has not been started on the server that executes the command, commands for any mode other than the start mode, status mode, register mode, and unregister mode terminate with an error.
Execute this command as a user with the "Administrator" privilege (operating system user ID that belongs to the Administrator group).
Until you start Mirroring Controller of standby server after starting Mirroring Controller of the primary server, operation can be started with only the primary server. Standby server is incorporated when you start the Mirroring Controller of standby server, and you should be able to operate in the multiplexing configuration.
Options
Specify this option to stop Mirroring Controller on all servers.
Specify this option to forcibly stop Mirroring Controller on the active server.
Specify this option to enable automatic switching and disconnection of Mirroring Controller immediately after startup.
This option is the default of start mode.
This option is the default of start mode and register mode.
Specify this option to disable automatic switching and disconnection immediately after startup of Mirroring Controller.
Specify this option to connect the Mirroring Controller start process asynchronously to the Mirroring Controller arbitration process. This option can be specified to forcibly start Mirroring Controller if the Mirroring Controller arbitration process is not started.
Specify this option if using the Mirroring Controller arbitration server.
Specify this option to display the connection status of the Mirroring Controller arbitration process. This option can be specified if using status mode.
Specify this option if using the Mirroring Controller arbitration server.
If you run a simulation build of the primary and standby servers in a single server (for system testing, for example), specify this option to identify the server to be operated.
For server_id, specify the server identifier specified in the network.conf file. ASCII characters other than single-byte space can be specified in the server identifier. The operations will be executed as if the user has logged in to server_id.
Specify this option to start and stop only Mirroring Controller processes. At the start mode, this option can be specified only while the database instance is running. If this option is omitted, the database instance is simultaneously started and stopped.
Specify the Mirroring Controller management directory.
ASCII characters can be specified in the directory path.
If this option is omitted, the value of the environment variable MCCONTROLDIR is used.
Switching with this option specified can only be specified on the standby server. This option is used to perform switching forcibly after performing fencing on the primary server if communication with the Mirroring Controller process of the other server is not possible (due to a network issue between database servers or unresponsive server, for example), thus preventing normal switching. However, if the --no-fencing option is specified, fencing will not be performed on the primary server.
When switching or disconnection is executed with the --force option specified, fencing of the server to be degraded is circumvented. Therefore, it is necessary for the user to isolate the server to be degraded from the cluster system in advance.
-P passwordFor the register mode, specify the password for the user who executed the command.
-S a[uto] | d[emand]Specify the start type for the Windows service to be registered. You can choose auto or demand as the start type by specifying the entire word or just its first letter. The default is auto.
Waits for operations to finish.
This option is the default of start mode.
This option is the default of start mode and register mode.
Does not wait for operations to finish.
Environment variable
Specifies the Mirroring Controller management directory.
ASCII characters can be specified in the directory path.
You can specify the -M option to override this value.
Diagnostics
0: Normal end
Other: Abnormal end
Notes
The message under execution might be output though the mc_ctl command is not being executed and, besides, it terminate abnormally when the server is downed while processing execution of this command, an automatic switch, and an automatic separation, and the communication between a primary server and the standby server is cut off. Besides, restart Mirroring Controller to solve this problem after confirming that the mc_ctl command is not in progress. Afterwards, execute a necessary operation.
If a time-out error occurs when the mc_ctl command is in progress, the messages may be different from the processes. Take the actions described in the "Action" section of the message.
Automatic switching and disconnection by the enable-failover mode, the disable-failover mode, and the start mode can be enabled/disabled only while Mirroring Controller is running. Therefore, if you want to enable/disable automatic switching and disconnection on starting, specify the -f option or -F option each time you start Mirroring Controller.
Use the start mode and stop mode to start and stop the Windows service. To do this, use the register mode to register Mirroring Controller as a Windows service in advance.
In case of postgresql.conf has any incorrect parameter when this command is executed, this command may be abnormally terminated. If this is the case, re-execute it again after correct the parameter in postgresql.conf.
If the arbitration server of Mirroring Controller is used, connection with the arbitration server will be performed on startup even if startup using start mode is executed with the -F option specified, or if executed with --local-server specified.
The mc_ctl command must be executed from "Administrator: Command Prompt". Right-click [Command Prompt], and then select [Run as administrator] from the menu to display the [Administrator: Command Prompt] window.
For operation using an arbitration server, the amount of time spent attempting to connect with the arbitration server is calculated, so the Mirroring Controller startup time may take longer.
Example
To start Mirroring Controller:
$ mc_ctl start -M /mcdir/inst1
To start Mirroring Controller:
> mc_ctl start -M D:\mcdir\inst1
mirroring status ---------------- (1) server_id host_role host host_status db_proc_status disk_status (2) (3) (4) (5) (6) (7)
(1) Multiplexing status
switchable : Switchable
switching : Switching
switched : Switched (displayed when switching has finished and the degrading operations status has been enabled)
not-switchable : Not switchable (displayed when a server is disconnected and switching is not possible)
unknown : Unknown (*1)
failover-disabled : Failover is disabled
(2) Server identifier
(3) Server role
primary : Primary
standby : Standby
none(inactivated primary): No role
(primary is stopped or being defined as primary)
none(inactivated standby): No role
(standby is stopped or being defined as primary)
(4) Host name or IP address
(5) Live/dead state of the server
normal : Normal operation
abnormal : Abnormal
unknown : Unknown (*1)
(6) DBMS process status
normal : Normal
abnormal (abnormal process name (*2)) : Abnormal
unknown : Unknown (*1)
(7) Disk status
normal : Normal
abnormal (abnormal disk type (*3)) : Abnormal
unknown : Unknown (*1)*1: Displayed when Mirroring Controller is stop state, the management network is abnormal, or Mirroring Controller has failed or is unresponsive.
*2: The names of the DBMS processes in which the abnormality was detected are output. The name has the following meaning: However, if multiple DBMS process issues are detected, only the DBMS for which the first issue was detected is displayed.
-postmaster: Process (postmaster) that accepts application connections
-wal_sender or wal_receiver: Process (WAL sender or WAL receiver) that sends and receives transaction logs
*3: The types of disks where the abnormality was detected are output separated by a comma. The type has the following meaning:
-data: Data storage disk
-tran_log: Transaction log storage disk
-tablespace: Tablespace storage diskarbiter_id host status (1) (2) (3)
(1) Arbitration server identifier
(2) Host name or IP address
(3) Mirroring Controller arbitration process connection status
online : Connected
offline : Disconnected (*1)*1: When Mirroring Controller is stopped, connections to the Mirroring Controller arbitration process cannot be established, so it will be displayed as "offline".