PostgreSQL Cluster Functions

Owned by Vijayganesh Sivaprakasam
Last updated: Aug 28, 2023
5 min read

 

1. Configuration and Cluster Information

This option is used to display the information regarding

  • Parameters relevant to the type of DR cluster created

  • The databases that are in the cluster

  • Size of the databases

  • The overall size of the cluster

  • tablespace information

To view the cluster information, Click on any PostgreSQL configuration on the dashboard, and on the right ACTIONS pane, this option is available.

1.1 Generic Cluster Information

  1. The information displayed is of the Primary Cluster. The standby information is almost the same.

  2. The status of the primary cluster (online). On standby, this might be either Hot Standby or Warm Standby.

  3. The database name and their sizes that are in the cluster

  4. The total number of databases.

  5. The total size of the databases that reside in the cluster

  6. The default and non-default tablespaces that reside in the cluster.

 

2. Configuration information

2.1 Configuration Information for Streaming Mode.

  1. The Configuration name along with the status of the DR.

  2. The mode using which the DR cluster was created (WAL STREAMING).

  3. The backup location and the port in which the primary cluster is running.

  4. The backup location and the port in which the standby cluster is running.

  5. The listen_address parameter and its value from postgresql.conf file.

2.2 Configuration Information for WAL Archiving Mode.

  1. The configuration name and the status of the configuration (In Sync)

  2. The method used for creating the DR cluster (WAL Archiving).

  3. The backup location in primary where the WAL Archive files are copied with the port of the cluster.

  4. The restore location where the WAL files are copied on the standby with the port of the standby cluster.

  5. The configuration parameter changes done by Dbvisit

    1. archive_command

    2. archive_mode

    3. archive_timeout

    4. restore_command

    5. archive_cleanup_command

 

2.3 Configuration Information for WAL Shipping Mode.

  1. The configuration name and the time gap information are displayed based on how far the standby cluster is behind the primary(The sync happens based on the automated standby update settings provided during DR cluster creation).

  2. The method using which the standby cluster was created(WAL Shipping Method).

  3. The backup location on the primary where the wal files are copied and the port of the Primary cluster.

  4. The location where the wal files are copied to the standby cluster and the port of the standby cluster.

 

 

3. Start/Stop Cluster

Both the primary and standby clusters can be stopped and started directly from the control center. This action can be performed irrespective of the method used for creating the DR cluster.

  1. The Selected cluster to perform the operation (Primary).

  2. The status of the cluster (online)

  3. The start button is greyed out as the cluster is already up and running.

  4. Click the stop button to stop the cluster.

  5. Click the restart button to stop and start the cluster to Online.

 

  1. The Selected cluster to perform the operation (Standby).

  2. The status of the cluster (Hot Standby)

  3. The start button is greyed out as the cluster is already up and running.

  4. Click the stop button to stop the cluster.

  5. Click the restart button to stop and start the cluster in Hot Standby mode.

 

4. WAL Shipping mode options.

There are four options specific to WAL Shipping mode.

  • Backup and send Logs

  • Apply Logs

  • Automated Standby Update

  • Standby update delay

4.1 Backup and send logs.

This option is available only on WAL Shipping mode manually.

  1. Click on Backup & Send Logs to manually copy the wal logs from primary to standby.

  2. Click on start to begin the operation.

  3. The current time gap information that displays how far the standby is behind the primary.

 

 

 

4.2 Apply Logs

  1. Click on Apply Logs to manually apply the copied wal logs on standby.

  2. Click on Start to begin the operation.

  3. The current time gap information that displays how far the standby is behind the primary.

 

 

 

4.3 Automated Standby Update

The automated standby update ( 1 ) option is only available for the WAL Shipping method. By default,

this option is enabled ( 2 ) and the time is set to 300 sec ( 4 ). This ensures that the wal files are copied from primary to standby every 5mins and applied on the standby. The time gap information ( 4 ) will be updated as soon the wal files are applied every 5 mins. The minimum value that can be set is 60sec for the automated standby update.

 

4.4 Standby update delay.

This option can be set only for the WAL Shipping method. When this option is set, the WAL files are still copied from primary to standby, but the WAL files are not applied on the standby. The standby is always kept at a delay.

  1. The option is available only for WAL Shipping method.

  2. The update delay must be greater than the automated standby update time. In the below example, the automated standby update is set to 300sec (5 minutes). The update delay is set to 10 minutes. By, default the parameter is disabled and must be set manually.

  3. The time gap information shows the time delay of the standby with primary.

To disable this parameter set it to zero and then click on the set button.

 

Â