Stops or restarts a HAWQ system.
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]
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.
-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.
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.
hawq stopdisplays 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 stopis 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.
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
pg_hba.conf files after making configuration changes but do not shutdown the HAWQ array:
$ hawq stop cluster -u