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Enterprise Postgres 17 SP1 Reference

4.1 mc_arb

Name

mc_arb - Start, stop, and display the status of the Mirroring Controller arbitration process

Overview

mc_arb start [-M mcdir] [-w| -W]
mc_arb stop [-M mcdir] [-e]
mc_arb status [-M mcdir]

Description

mc_arb starts, stops, and displays the status of the Mirroring Controller arbitration process.

The start mode starts the Mirroring Controller arbitration process.

The stop mode stops the Mirroring Controller arbitration process.

The status mode displays the connection status of the Mirroring Controller arbitration process with the Mirroring Controller processes of the primary server and standby server.

If the Mirroring Controller arbitration process has not been started on the server executing the command, stop mode and status mode will terminate with an error.

Additionally, if Mirroring Controller is forcibly stopped on the database server, it may take a few moments until the status mode displays the status of the server connection as offline.

This command can be executed by any user.

Options

-e

Specify this option to forcibly stop the Mirroring Controller arbitration process on the active server.

Specify this option to stop the Mirroring Controller arbitration process but keep Mirroring Controller running (to stop both, first stop Mirroring Controller of the database server, and then the Mirroring Controller arbitration process). This option can also be specified to halt the arbitration process (by stopping the Mirroring Controller arbitration process) when the fencing command called by the arbitration process becomes unresponsive.

-M mcdir

Specify the Mirroring Controller arbitration process management directory.

ASCII characters can be specified in the directory path.

If this option is omitted, the value of the environment variable ARBCONTROLDIR is used.

-w

Waits for operations to finish.

This option is the default of start mode.

-W

Does not wait for operations to finish.

Environment

ARBCONTROLDIR

Specify the Mirroring Controller arbitration process 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 than 0: Abnormal end

Notes

If the Mirroring Controller arbitration process is forcibly stopped or communication between the command and the Mirroring Controller arbitration process is interrupted while the Mirroring Controller arbitration process is being stopped, a message that the command is being executed may be output and stopping may terminate in error, even though no other instances of the mc_arb command are being executed.
To solve this issue, ensure that other instances of the mc_arb command are not being executed before forcibly stopping the Mirroring Controller arbitration process.

Example

Start the Mirroring Controller arbitration process.

$ mc_arb start -M /mcarb_dir/arbiter1
Display details of mc_arb status
server_id   host            status
(1)         (2)             (3)
(1) Server identifier
(2) Host name or IP address
(3) Server connection status
    online   : Connected
    offline  : Disconnected