gpconfig

Sets server configuration parameters on all segments within a LightDB-A Database system.

Synopsis

gpconfig -c <param_name> -v <value> [-m <coordinator_value> | --masteronly]
       | -r <param_name> [--masteronly]
       | -l
       [--skipvalidation] [--verbose] [--debug]

gpconfig -s <param_name> [--file | --file-compare] [--verbose] [--debug]

gpconfig --help

Description

The gpconfig utility allows you to set, unset, or view configuration parameters from the postgresql.conf files of all instances (coordinator, segments, and mirrors) in your LightDB-A Database system. When setting a parameter, you can also specify a different value for the coordinator if necessary. For example, parameters such as max_connections require a different setting on the coordinator than what is used for the segments. If you want to set or unset a global or coordinator only parameter, use the --masteronly option.

Note For configuration parameters of vartype string, you may not pass values enclosed in single quotes to gpconfig -c.

gpconfig can only be used to manage certain parameters. For example, you cannot use it to set parameters such as port, which is required to be distinct for every segment instance. Use the -l (list) option to see a complete list of configuration parameters supported by gpconfig.

When gpconfig sets a configuration parameter in a segment postgresql.conf file, the new parameter setting always displays at the bottom of the file. When you use gpconfig to remove a configuration parameter setting, gpconfig comments out the parameter in all segment postgresql.conf files, thereby restoring the system default setting. For example, if you use gpconfigto remove (comment out) a parameter and later add it back (set a new value), there will be two instances of the parameter; one that is commented out, and one that is enabled and inserted at the bottom of the postgresql.conf file.

After setting a parameter, you must restart your LightDB-A Database system or reload the postgresql.conf files in order for the change to take effect. Whether you require a restart or a reload depends on the parameter.

For more information about the server configuration parameters, see the LightDB-A Database Reference Guide.

To show the currently set values for a parameter across the system, use the -s option.

gpconfig uses the following environment variables to connect to the LightDB-A Database coordinator instance and obtain system configuration information:

• PGHOST
• PGPORT
• PGUSER
• PGPASSWORD
• PGDATABASE

Options

-c | –change param_name : Changes a configuration parameter setting by adding the new setting to the bottom of the postgresql.conf files.

-v | –value value : The value to use for the configuration parameter you specified with the -c option. By default, this value is applied to all segments, their mirrors, the coordinator, and the standby coordinator.

: The utility correctly quotes the value when adding the setting to the postgresql.conf files.

: To set the value to an empty string, enter empty single quotes ('').

-m | –mastervalue coordinator_value : The coordinator value to use for the configuration parameter you specified with the -c option. If specified, this value only applies to the coordinator and standby coordinator. This option can only be used with -v.

–masteronly : When specified, gpconfig will only edit the coordinator postgresql.conf file.

-r | –remove param_name : Removes a configuration parameter setting by commenting out the entry in the postgresql.conf files.

-l | –list : Lists all configuration parameters supported by the gpconfig utility.

-s | –show param_name : Shows the value for a configuration parameter used on all instances (coordinator and segments) in the LightDB-A Database system. If there is a difference in a parameter value among the instances, the utility displays an error message. Running gpconfig with the -s option reads parameter values directly from the database, and not the postgresql.conf file. If you are using gpconfig to set configuration parameters across all segments, then running gpconfig -s to verify the changes, you might still see the previous (old) values. You must reload the configuration files (gpstop -u) or restart the system (gpstop -r) for changes to take effect.

–file : For a configuration parameter, shows the value from the postgresql.conf file on all instances (coordinator and segments) in the LightDB-A Database system. If there is a difference in a parameter value among the instances, the utility displays a message. Must be specified with the -s option.

: For example, the configuration parameter statement_mem is set to 64MB for a user with the ALTER ROLE command, and the value in the postgresql.conf file is 128MB. Running the command gpconfig -s statement_mem --file displays 128MB. The command gpconfig -s statement_mem run by the user displays 64MB.

: Not valid with the --file-compare option.

–file-compare : For a configuration parameter, compares the current LightDB-A Database value with the value in the postgresql.conf files on hosts (coordinator and segments). The values in the postgresql.conf files represent the value when LightDB-A Database is restarted.

: If the values are not the same, the utility displays the values from all hosts. If all hosts have the same value, the utility displays a summary report.

: Not valid with the --file option.

–skipvalidation : Overrides the system validation checks of gpconfig and allows you to operate on any server configuration parameter, including hidden parameters and restricted parameters that cannot be changed by gpconfig. When used with the -l option (list), it shows the list of restricted parameters.

> **Caution** Use extreme caution when setting configuration parameters with this option.

–verbose : Displays additional log information during gpconfig command execution.

–debug : Sets logging output to debug level.

-? | -h | –help : Displays the online help.

Examples

Set the max_connections setting to 100 on all segments and 10 on the coordinator:

gpconfig -c max_connections -v 100 -m 10

These examples shows the syntax required due to bash shell string processing.

gpconfig -c search_path -v '"\$user",public'
gpconfig -c dynamic_library_path -v '\$libdir'

The configuration parameters are added to the postgresql.conf file.

search_path='"$user",public'
dynamic_library_path='$libdir'

Comment out all instances of the default_statistics_target configuration parameter, and restore the system default:

gpconfig -r default_statistics_target

List all configuration parameters supported by gpconfig:

gpconfig -l

Show the values of a particular configuration parameter across the system:

gpconfig -s max_connections

See Also

gpstop