gpstart

Starts a Greenplum Database system.

Synopsis

gpstart [-d <master_data_directory>] [-B <parallel_processes>] [-R]
        [-m] [-y] [-a] [-t <timeout_seconds>] [-l <logfile_directory>] 
        [--skip-heap-checksum-validation]
        [-v | -q]

gpstart -? | -h | --help 

gpstart --version

Description

The gpstart utility is used to start the Greenplum Database server processes. When you start a Greenplum Database system, you are actually starting several postgres database server listener processes at once (the master and all of the segment instances). The gpstart utility handles the startup of the individual instances. Each instance is started in parallel.

The first time an administrator runs gpstart, the utility creates a hosts cache file named .gphostcache in the user's home directory. Subsequently, the utility uses this list of hosts to start the system more efficiently. If new hosts are added to the system, you must manually remove this file from the gpadmin user's home directory. The utility will create a new hosts cache file at the next startup.

As part of the startup process, the utility checks the consistency of heap checksum setting among the Greenplum Database master and segment instances, either activated or deactivated on all instances. If the heap checksum setting is different among the instances, an error is returned and Greenplum Database does not start. The validation can be deactivated by specifying the option --skip-heap-checksum-validation. For more information about heap checksums, see Enabling High Availability and Data Consistency Features in the Greenplum Database Admininstartor Guide.

Note: Before you can start a Greenplum Database system, you must have initialized the system using gpinitsystem. Enabling or disabing heap checksums is set when you initialize the system and cannot be changed after initialization.

If the Greenplum Database system is configured with a standby master, and gpstart does not detect it during startup, gpstart displays a warning and lets you cancel the startup operation.

• If the -a option (deactivate interactive mode prompts) is not specified, gpstart displays and logs these messages:

  Standby host is unreachable, cannot determine whether the standby is currently acting as the master. Received error: <error>
  Continue only if you are certain that the standby is not acting as the master.
  

  It also displays this prompt to continue startup:

  Continue with startup Yy|Nn (default=N):
  

• If the -a option is specified, the utility does not start the system. The messages are only logged, and gpstart adds this log message:

  Non interactive mode detected. Not starting the cluster. Start the cluster in interactive mode.
  

If the standby master is not accessible, you can start the system and troubleshoot standby master issues while the system is available.

Options

-a

Do not prompt the user for confirmation. Deactivates interactive mode.

-B parallel_processes

The number of segments to start in parallel. If not specified, the utility will start up to 64 parallel processes depending on how many segment instances it needs to start.

-d master_data_directory

Optional. The master host data directory. If not specified, the value set for $MASTER_DATA_DIRECTORY will be used.

-l logfile_directory

The directory to write the log file. Defaults to ~/gpAdminLogs.

-m

Optional. Starts the master instance only, which may be useful for maintenance tasks. This mode only allows connections to the master in utility mode. For example:

PGOPTIONS='-c gp_session_role=utility' psql

The consistency of the heap checksum setting on master and segment instances is not checked.

-q

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

-R

Starts Greenplum Database in restricted mode (only database superusers are allowed to connect).

--skip-heap-checksum-validation

During startup, the utility does not validate the consistency of the heap checksum setting among the Greenplum Database master and segment instances. The default is to ensure that the heap checksum setting is the same on all instances, either activated or deactivated.

Warning: Starting Greenplum Database without this validation could lead to data loss. Use this option to start Greenplum Database only when it is necessary to ignore the heap checksum verification errors to recover data or to troubleshoot the errors.

-t timeout_seconds

Specifies a timeout in seconds to wait for a segment instance to start up. If a segment instance was shutdown abnormally (due to power failure or killing its postgres database listener process, for example), it may take longer to start up due to the database recovery and validation process. If not specified, the default timeout is 60 seconds.

-v

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

-y

Optional. Do not start the standby master host. The default is to start the standby master host and synchronization process.

-? | -h | --help

Displays the online help.

--version

Displays the version of this utility.

Examples

Start a Greenplum Database system:

gpstart

Start a Greenplum Database system in restricted mode (only allow superuser connections):

gpstart -R

Start the Greenplum master instance only and connect in utility mode:

gpstart -m 
PGOPTIONS='-c gp_session_role=utility' psql

See Also

gpstop, gpinitsystem