Ensure server parameter 'connection_throttle.enable' is set to 'ON' for PostgreSQL flexible servers

Overview

Enable connection throttling on PostgreSQL flexible servers.

Rationale

Enabling connection throttling helps the PostgreSQL Database to Set the verbosity of logged messages. This, in turn, generates query and error logs with respect to concurrent connections that could lead to a successful Denial of Service (DoS) attack by exhausting connection resources. A system can also fail or be degraded by an overload of legitimate users. Query and error logs can be used to identify, troubleshoot, and repair configuration errors and sub-optimal performance.

Default Value

By default, connection_throttle.enable is disabled (set to off).

Remediation guidance

Remediate from Azure Portal

Open the server using the Open in Azure button
Under Settings, click Server parameters.
In the filter bar, type connection_throttle.enable.
Set the VALUE for connection_throttle.enable to ON.
Click Save.

Remediate from Azure CLI

Use the below command to enable connection_throttle.enable:

az postgres flexible-server parameter set --resource-group <resourceGroup> --server-name <serverName> --name connection_throttle.enable --value on

Remediate from PowerShell

Update-AzPostgreSqlFlexibleServerConfiguration -ResourceGroupName <resourceGroup> -ServerName <serverName> -Name connection_throttle.enable -Value on

Multiple Remediation Paths

Azure

SERVICE-WIDE (RECOMMENDED when many resources are affected): Assign Azure Policy initiatives at management group/subscription scope and trigger remediation tasks.

az policy assignment create --name <assignment-name> --scope /subscriptions/<subscription-id> --policy-set-definition <initiative-id>
az policy remediation create --name <remediation-name> --policy-assignment <assignment-id>

ASSET-LEVEL: Apply the resource-specific remediation steps above to the listed non-compliant resources.

PREVENTIVE: Embed Azure Policy checks into landing zones and IaC workflows to block or auto-remediate drift.

References for Service-Wide Patterns

Azure Policy overview: https://learn.microsoft.com/en-us/azure/governance/policy/overview
Azure Policy remediation: https://learn.microsoft.com/en-us/azure/governance/policy/how-to/remediate-resources
Azure Policy initiative structure: https://learn.microsoft.com/en-us/azure/governance/policy/concepts/initiative-definition-structure

Operational Rollout Workflow

Use this sequence to reduce risk and avoid repeated drift.

1. Contain at Service-Wide Scope First (Recommended)

Azure: assign policy initiatives at management group/subscription scope and run remediation tasks.

az policy assignment create --name <assignment-name> --scope /subscriptions/<subscription-id> --policy-set-definition <initiative-id>
az policy remediation create --name <remediation-name> --policy-assignment <assignment-id>

2. Remediate Existing Affected Assets

Execute the control-specific Console/CLI steps documented above for each flagged resource.
Prioritize internet-exposed and production assets first.

3. Validate and Prevent Recurrence

Re-scan after each remediation batch.
Track exceptions with owner and expiry date.
Add preventive checks in IaC/CI pipelines.

Query logic

These are the stored checks tied to this control.

Azure PostgreSQL Flex Servers Without Connection Throttling

Connectors

Microsoft Azure

Covered asset types

PostgreSQLFlexibleServer

Expected check: eq []

{
  postgreSqlFlexibleServers(
    where: {
      configurations_SOME: {
        name: "connection_throttle.enable"
        value_MATCHES: "(?i)off"
      }
    }
  ) {
    ...AssetFragment
  }
}