Preparation Commands

Updated on 2025-01-09 GMT+08:00

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Function

The prepare command is used to set GUC parameters for the active/standby fine-grained DR cluster in one-click mode.

Syntax

python3 $GPHOME/script/DisasterFineGrained.py -t prepare --local-dn-num <localDnNum> --remote-dn-num <remoteDnNum> --config-file <configFile>

Parameter Description

Long Option	Short Option	Data Type	Description	Range	Default Value	Example
-t	N/A	String	The interface supports multiple functions. Set this parameter to prepare to prepare for the active/standby cluster.	-t generate-config -t prepare -t create-publication -t alter-publication -t cancel-publication -t get-current-disaster	N/A	-t prepare
--local-dn-num	N/A	String	Number of DNs in the local cluster	N/A	N/A	--local-dn-num 6
--remote-dn-num	N/A	String	Number of DBs in the remote cluster	N/A	N/A	--remote-dn-num 3
--config-file	N/A	String	Path of the dual-cluster DR configuration file. NOTE: Ensure user omm has the read permission for this path. For details about how to configure the configuration file, see Commands for Generating a Configuration File.	N/A	N/A	--config-file /home/userA/config.ini

Usage Guide

The prepare command must be executed on the active node of the active cluster.

**Table 1** Configuring GUC parameters
Cluster	Parameter	Parameter Description	Value Range	Value
Active/Standby cluster	enable_metadata_tracking	In the primary cluster for fine-grained DR, this parameter is used to track metadata (including DDL and DCL) changes of objects related to fine-grained DR and synchronize changed metadata to the standby cluster.	Boolean on indicates that the metadata change tracking function is enabled. Metadata changes can be synchronized to the standby cluster through fine-grained DR. off indicates that the metadata change tracking function is disabled.	on
Active/Standby cluster	disaster_cluster_dn_nums	Specifies the number of DNs in the primary/standby cluster for fine-grained DR, in the format of Number of DNs in the local cluster,Number of databases in the remote cluster. This parameter is used for data bucketing during synchronization from a small cluster to a large cluster.	A string. Set this parameter based on DNs in the primary and standby clusters. For example, if the ratio of DNs is 6:3, set this parameter to 6,3 and 3,6 for large and small clusters, respectively.	Command line input
Standby cluster	view_independent	Enables or disables the view decoupling function.	Boolean on indicates that the view decoupling function is enabled. off indicates that the view decoupling function is disabled.	on

Example Command

Prepare the active/standby cluster.

python3 $GPHOME/script/DisasterFineGrained.py -t prepare --local-dn-num 3 --remote-dn-num 3 --config-file /home/mpp/mppcases_c10/cluster/gs_rch_DR-v6/test/backupRestore.ini

System Response

[perfadm@ecs-env-2988 test]$ python3 $GPHOME/script/DisasterFineGrained.py -t prepare --local-dn-num 3 --remote-dn-num 3 --config-file /home/mpp/mppcases_c10/cluster/gs_rch_DR-v6/test/backupRestore.ini
[Start ESL disaster fine grained process]
set guc 'enable_metadata_tracking' to 'on' on 192.168.250.152.
set guc 'disaster_cluster_dn_nums' to '3,3' on 192.168.250.152.
set guc 'enable_metadata_tracking' to 'on' on 192.168.244.53.
set guc 'disaster_cluster_dn_nums' to '3,3' on 192.168.244.53.
set guc 'view_independent' to 'on' on 192.168.244.53.
Success set guc prepare.
[Finished ESL disaster fine grained process]

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