Create and Manage PostgreSQL Cluster

PostgreSQL Cluster enables deploying a database with a 1 Writer + N Readers architecture, ensuring High Availability and the ability to scale read operations for your application. When the Writer encounters an issue, the system automatically fails over to a Reader without manual intervention.

For more information about concepts, architecture, and the comparison between Single Node and Cluster, please refer to PostgreSQL Cluster.

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Create a PostgreSQL Cluster

Access the vDB Portal

You can access the vDB service interface in 2 ways:

• Option 1: Go to the GreenNode homepage at https://dashboard.console.vngcloud.vn/. On the main interface, navigate to vServer and select vDB Relational from the list of vServer products/services.

• Option 2: Go directly to the vDB Relational homepage at https://vdb.console.vngcloud.vn/relational/database

Create a PostgreSQL Cluster

On the Database management interface, click Create Database. The creation process goes through the following steps:

Step 1: Basic Configuration

• Cluster Name: Enter a name for the cluster (6-20 characters, must start with a letter).

• Database Engine: Select PostgreSQL.

• Deployment Type: Select Cluster (this option only appears when the Engine is PostgreSQL).

When selecting Cluster as the Deployment Type, the label changes from "Database Instance Name" to "Cluster Name".

Restore from Backup (optional):

When selecting Cluster as the Deployment Type, the system also displays a Backup Image section that allows you to restore the cluster from an existing backup:

• Expand a backup item to view restore points.

• Select a restore point if you want to create a cluster with data from that backup.

• If no restore point is selected, the cluster will be created with an empty database.

Note: When restoring from a backup, the Storage Size of the new cluster must be greater than or equal to the Backup Size of the selected backup.

Step 2: Specifications

• Engine Version: Select the PostgreSQL version (e.g., 15, 14, 13...).

• Flavor: Select the instance configuration (vCPU, RAM). This configuration applies to all nodes in the cluster.

• Storage Type: Select the storage disk type.

• Storage Size: Select the storage capacity (includes data and logs).

• Number of Nodes: Select the number of nodes for the cluster (from 2 to 10). The system will display the corresponding Role Distribution:

Number of Nodes	Role Distribution
2	1 Writer + 1 Reader
3	1 Writer + 2 Readers
5	1 Writer + 4 Readers
10	1 Writer + 9 Readers

Step 3: DB Settings

• Master Username: Username for managing the database cluster.

Reserved Usernames: You must not use the following usernames: postgres, admin, cron_admin, robot_zmon, vngpooler, vngpam, vngrep, vngsuperrole.

• Master Password: Password for the master user. The password must meet the following requirements:

  • Length of 8-32 characters.

  • Allowed characters: A-Z, a-z, 0-9, and special characters ($, ^, _, <, >).

  • Must start with a letter (A-Z or a-z).

  • Must not start or end with a special character.

Step 4: Network & Security

• Cloud Network (VPC & Subnet): Select the VPC and Subnet for the cluster. If you don't have one yet, you can create a new one following the guide here.

• Public Accessibility: Enable if you want the cluster to have a Public IP and be accessible from the Internet; disable if you only want access via Private IP.

Note: The Public Accessibility setting can only be selected once at the time of creation and cannot be changed afterwards.

Step 5: DB Options

• Database Name: Name of the database that will be automatically initialized.

• DB Configuration Group (optional): Select a Configuration Group to apply to the cluster.

Step 6: Backup Settings

Backup Settings are mandatory when creating a PostgreSQL Cluster. You must select both a Backup Policy and a Backup Location.

• Backup Policy: Select the policy that defines the backup schedule and retention period from Backup Center.

• Backup Location: Select the backup storage location from Backup Center. The dropdown only shows locations with status = Available and Product = vDB, sorted in newest first order.

If no Backup Location is available:

If your account has no Backup Location in Available status, the Backup Location dropdown will appear with a red border and an error message. You need to click the link in the message to open Backup Center and create a new location before continuing to create the cluster.

If you don't have a Backup Policy yet, you can click the link to open Backup Center and create a new one.

Note: The Backup Location cannot be changed after the cluster has been created. Each cluster is permanently bound to a single Backup Location, so choose the appropriate location from the start.

Completion

In the Summary section on the right, review all configuration information. When everything is correct, click Create Database to complete. During initialization, the cluster will have Building status. When initialization is successful, the cluster will transition to Active status.

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Manage PostgreSQL Cluster

View Database List

On the Database List page, you can quickly filter databases by deployment type:

Tab	Description
All Databases	Shows all databases
Single Node	Shows only Single Node databases
Clusters	Shows only Cluster databases

View Cluster Details

When clicking on a cluster in the list, the detail page shows the following information:

General Information:

Information	Description	Example
ID	Cluster identifier	pg-1dfa6aaf-20c9-44a1-...
Zone	Availability Zone	HCM03-1A
Role	Instance role	Primary Writer / Replica Reader
Replica Source	Replica source (if any)	N/A
Instance Type	Instance configuration	db-postgre.s-general-2x4-n10 (2 Core, 4 GB)
Engine	Engine and deployment type	PostgreSQL 15 (Cluster, 3 Node)
Storage	Storage capacity and type	20 GB (GEN2-NVME-IOPS5000)
Free GB	Free backup capacity included with the package	20 GB
Configuration Group	Applied configuration group	default-group
Network	VPC network	vpc-10-10-0-0

Detail tabs:

Tab	Content
Configuration	Flavor information (vCPU, RAM) and storage (type, size, disk usage)
Connectivity & Security	Connection endpoints and security settings
Backup	Backup history, create manual backup, view backup information
History	Activity logs
Monitor	Metrics and monitoring charts

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Back Up Now

The Back up now button is displayed directly on the action bar of the cluster detail page (alongside Reboot, Edit Number of Nodes, Resize IOPS, Resize Storage Size), not inside the More Actions (⋮) menu.

1. On the cluster detail page, click Back up now on the action bar.

2. The system displays a confirmation dialog.

3. Click Confirm to start creating the backup.

After confirmation, the system triggers the creation of a Full Snapshot and displays a toast notification. The new backup appears in the Backup tab with In Progress status, transitioning to Completed when done.

Note:

• The Back up now button will be disabled when a backup job (Auto or Manual) is currently running. Hovering over the button will show a tooltip.

• If the account runs out of quota or is locked, the system returns an error and does not automatically retry.

Edit Number of Nodes

You can change the number of nodes in the cluster (from 2 to 10):

1. On the cluster detail page, click Edit Number of Nodes on the action bar.

2. Enter the desired number of nodes.

3. Confirm the change.

The system will automatically add or remove Reader nodes. The Writer node is not affected.

Resize IOPS

1. On the cluster detail page, click Resize IOPS on the action bar.

2. Select the new IOPS value.

3. Confirm the change.

Resize Storage Size

1. On the cluster detail page, click Resize Storage Size on the action bar.

2. Enter the new storage capacity (only increasing is supported, decreasing is not).

3. Confirm the change.

Edit Configuration Group

1. On the cluster detail page, click More Actions (⋮) > Edit Configuration Group.

2. Select the new Configuration Group.

3. Confirm the change.

Reboot Cluster

1. On the cluster detail page, click Reboot on the action bar.

2. Confirm the restart.

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Manage Backup

View Backup Information

On the cluster detail page, select the Backup tab to view:

• Backup Information: Overview including Description, Created Date, Latest Record, Backup Size, Backup Policy, Backup Location.

• Backup List: List of backups with Backup DB Point ID, Min.Restore Size (GB), Backup Type, Schedule Type, Backup Location, Backup Point, Status, Action (Restore / Delete).

At the top of the Backup tab there is a "View full backup details →" link that goes directly to the detailed backup page for the current cluster in Backup Center (opens in a new tab).

Create Manual Backup

There are 2 ways to create a Manual Backup:

• Option 1 (recommended): Click the Back up now button directly on the action bar of the cluster detail page (see guide at Back Up Now).

• Option 2: In the Backup tab, click Create Manual Backup, then confirm.

The system will create a Full Snapshot of the database. The new backup appears in the list with In Progress status, transitioning to Completed when done.

Note:

• Manual Backup only supports creating a Full Snapshot.

• Only 1 job backup/restore is allowed to run at a time. If Auto Backup is running, Manual Backup will be rejected.

• If the account runs out of quota or is locked, the system will return an error and will not automatically retry.

Restore from Backup

Restoring from a backup will create a new cluster (it does not restore over the existing cluster):

1. In the Backup tab, click Restore on the backup you want to restore.

2. Or when creating a new cluster, select the restore point in the Backup Image section in Step 1.

3. Configure the parameters for the new cluster (Storage Size must be >= Backup Size).

4. Complete the cluster creation.

vDB Backup Page

Go to Menu: Relational > Backup to view an overview of backups:

• When no backups exist: Displays a message and a Create a Backup button to go to Backup Center.

• When backups exist: Displays a list of backups and a Go to Backup Center button for full management (Download, Restore, Delete, Policy).

The vDB Backup page only allows viewing the backup list. To perform full management operations (Download, Restore, Delete), please go to Backup Center.

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Delete PostgreSQL Cluster

1. On the cluster detail page, click More Actions (⋮) > Delete.

2. The system displays a confirmation dialog with the following components:

   • "Create final backup?" checkbox (optional): Check this if you want to create a final backup before deletion.

   • Confirmation field: Enter delete to activate the Delete button.

3. Click Delete (red) to complete.

If the cluster no longer has a Backup Database in Backup Center:

• The "Create final backup?" checkbox will be disabled and cannot be selected.

• The system displays a notification.

• You still need to enter delete to confirm.

Note when deleting a Cluster:

• Auto Backup will be automatically deleted along with the cluster.

• Manual Backup will be retained. You need to manually delete it in Backup Center if no longer needed.

• The deletion action cannot be undone. Make sure you have backed up any necessary data before deleting.