hawq stop

Stops or restarts a HAWQ system.

Synopsis

hawq stop <object> [-a | --prompt]
       [-M (smart|fast|immediate) | --mode (smart|fast|immediate)]   
       [-t <timeout_seconds> | --timeout <timeout_seconds>]  
       [-l <logfile_directory> | --logdir <logfile_directory>]
       [(-v | --verbose) | (-q | --quiet)]
hawq stop [-? | -h | --help]

Description

The hawq stop utility is used to stop the database servers that comprise a HAWQ system. When you stop a HAWQ system, you are actually stopping several postgres database server processes at once (the master and all of the segment instances). The hawq stop utility handles the shutdown of the individual instances. Each instance is shut down in parallel.

By default, you are not allowed to shut down HAWQ if there are any client connections to the database. Use the -M fast option to roll back all in progress transactions and terminate any connections before shutting down. If there are any transactions in progress, the default behavior is to wait for them to commit before shutting down.

With the -u option, the utility uploads changes made to the master pg_hba.conf file or to runtime configuration parameters in the master hawq-site.xml file without interruption of service. Note that any active sessions will not pick up the changes until they reconnect to the database. If the HAWQ cluster has active connections, use the command hawq stop cluster -u -M fast to ensure that changes to the parameters are reloaded.

Objects

cluster

Stop a HAWQ cluster.

master

Shuts down a HAWQ master instance that was started in maintenance mode.

segment

Stop a local segment node.

standby

Stop the HAWQ standby master process.

allsegments

Stop all segments.

Options

-a, —prompt

Do not prompt the user for confirmation before executing.

-l, —logdir

The directory to write the log file. The default is ~/hawqAdminLogs/.

-M, —mode (smart | fast | immediate)

Smart shutdown is the default. Shutdown fails with a warning message, if active connections are found.

Fast shut down interrupts and rolls back any transactions currently in progress .

Immediate shutdown aborts transactions in progress and kills all postgres processes without allowing the database server to complete transaction processing or clean up any temporary or in-process work files. Because of this, immediate shutdown is not recommended. In some instances, it can cause database corruption that requires manual recovery.

-q, —quiet

Run in quiet mode. Command output is not displayed on the screen, but is still written to the log file.

-t, —timeout

Specifies a timeout threshold (in seconds) to wait for a segment instance to shutdown. If a segment instance does not shut down in the specified number of seconds, hawq stop displays a message indicating that one or more segments are still in the process of shutting down and that you cannot restart HAWQ until the segment instance(s) are stopped. This option is useful in situations where hawq stop is executed and there are very large transactions that need to rollback. These large transactions can take over a minute to rollback and surpass the default timeout period of 600 seconds.

-u, —reload

This option reloads configuration parameter values without restarting the HAWQ cluster.

-v, —verbose

Displays detailed status, progress and error messages output by the utility.

-?, -h, —help (help)

Displays the online help.

Examples

Stop a HAWQ system in smart mode:

$ hawq stop cluster -M smart

Stop a HAWQ system in fast mode:

$ hawq stop cluster -M fast

Stop a master instance that was started in maintenance mode:

$ hawq stop master -m

Reload the hawq-site.xml and pg_hba.conf files after making configuration changes but do not shutdown the HAWQ array:

$ hawq stop cluster -u

See Also

hawq start