SHUTDOWN SERVER

SQream’s method for stopping the SQream server is running the shutdown_server() utility command. Because this command abruptly shuts down the server while executing operations, it has been modified to perform a graceful shutdown by setting it to select shutdown_server([is_graceful, [timeout]]);. This causes the server to wait for any queued statements to complete before shutting down.

How Does it Work?

Running the SHUTDOWN_SERVER command gives you more control over the following:

  • Preventing new queries from connecting to the server by:

    • Setting the server as unavailable in the metadata server.

    • Unsubscribing the server from its service.

  • Stopping users from making new connections to the server. Attempting to connect to the server after activating a graceful shutdown displays the following message:

    Server is shutting down, no new connections are possible at the moment.

  • The amount of time to wait before shutting down the server.

  • Configurations related to shutting down the server.

Syntax

The following is the syntax for using the SHUTDOWN_SERVER command:

select shutdown_server([true/false, [timeout]]);

Returns

Running the shutdown_server command returns no output.

Parameters

The following table shows the shutdown_server parameters:

Parameter

Description

Example

Default

is_graceful

Determines the method used to shut down the server.

Selecting false shuts down the server while queries are running. Selecting true uses the graceful shutdown method.

NA

timeout

Sets the maximum amount of minutes for the graceful shutdown method to run before the server is shut down using the standard method.

([is_graceful, [30]]);

Five minutes

Note

Setting is_graceful to false and defining the timeout value shuts the server down mid-query after the defined time.

You can define the timeout argument as the amount minutes after which a forceful shutdown will run, even if a graceful shutdown is in progress.

Note that activating a forced shutdown with a timeout, such as select shutdown_server(false, 30), outputs the following error message:

forced shutdown has no timeout timer

Note

You can set the timeout value using the defaultGracefulShutdownTimeoutMinutes flag in the Acceleration Studio.

Examples

This section shows the following examples:

Example 1 - Activating a Forceful Shutdown

shutdown_server()

Example 2 - Activating a Graceful Shutdown

shutdown_server (true)

Example 3 - Overriding the timeout Default with Another Value

shutdown_server (500)

The timeout unit is minutes.

Permissions

The SUPERUSER permission is required to execute shutdown_server.