By default, Platform Content Delivery Network (CDN) provides an edge delivery layer for Source CMS sites. To route traffic directly to Acquia infrastructure, disable Platform CDN for individual sites. Use this configuration to troubleshoot CDN-layer performance issues or to meet enterprise security requirements such as Web Application Firewall (WAF) integration. This document provides instructions to disable and re-enable Platform CDN for Source CMS sites through the Sites Dashboard.

Prerequisites

Before you modify Platform CDN settings, ensure that you meet the following requirements:

• Role requirement: Users requires the site administrator role in the Sites Dashboard to manage CDN settings.
• Custom domain certificates: If the site uses custom domains, valid Secure Sockets Layer (SSL) certificates must be installed for those domains through the Sites Dashboard to remain protected. These uploaded certificates continue to terminate traffic on Acquia infrastructure. Acquia manages wildcard certificates on Acquia balancers to handle Secure Sockets Layer coverage for Acquia-managed domains. The toggle action does not change HTTPS behavior for visitors, and all traffic remains encrypted.

Enterprise WAF Integration

If your organization requires a WAF to process site traffic before it reaches Acquia infrastructure, deactivate Platform CDN and configure the WAF to route traffic to the Acquia balancer endpoint provided in the View DNS Information modal. This configuration enables traffic to flow through your WAF before it reaches Acquia infrastructure. 

By default, Platform Content Delivery Network (CDN) provides an edge delivery layer for Source CMS sites. To route traffic directly to Acquia infrastructure, disable Platform CDN for individual sites. Use this configuration to troubleshoot CDN-layer performance issues or to meet enterprise security requirements such as Web Application Firewall (WAF) integration. This document provides instructions to disable and re-enable Platform CDN for Source CMS sites through the Sites Dashboard.

Prerequisites

Before you modify Platform CDN settings, ensure that you meet the following requirements:

• Role requirement: Users requires the site administrator role in the Sites Dashboard to manage CDN settings.
• Custom domain certificates: If the site uses custom domains, valid Secure Sockets Layer (SSL) certificates must be installed for those domains through the Sites Dashboard to remain protected. These uploaded certificates continue to terminate traffic on Acquia infrastructure. Acquia manages wildcard certificates on Acquia balancers to handle Secure Sockets Layer coverage for Acquia-managed domains. The toggle action does not change HTTPS behavior for visitors, and all traffic remains encrypted.

Enterprise WAF Integration

If your organization requires a WAF to process site traffic before it reaches Acquia infrastructure, deactivate Platform CDN and configure the WAF to route traffic to the Acquia balancer endpoint provided in the View DNS Information modal. This configuration enables traffic to flow through your WAF before it reaches Acquia infrastructure. 

Performance Considerations

Without Platform CDN, all requests reach Acquia balancers directly because global edge nodes do not cache content. Visitors geographically distant from the Acquia data center can experience higher latency.

Acquia recommends to deactivate Platform CDN only when required for WAF integration, enterprise security compliance, or to troubleshoot. Activate Platform CDN to restore global edge cache performance when no longer needed. 

Platform CDN features, such as IP address restrictions at the edge level, are unavailable while Platform CDN is inactive. The configuration applies to individual sites because there is no platform-wide toggle feature.

When Platform CDN is inactive, consider the following performance impacts:

Platform CDN operations

By default, all Source CMS sites route public traffic through Platform CDN. The CDN caches content at globally distributed edge nodes to reduce page load times for visitors.

When Platform CDN is active, traffic flows through the following sequence:

1. Visitor
2. Platform CDN edge cache
3. Acquia balancers that use Varnish
4. Drupal application

When Platform CDN is inactive, traffic flows through the following sequence:

1. Visitor
2. Acquia balancers that route from nginx to Varnish
3. Drupal application

If you disable Platform CDN, the platform removes only the CDN layer. The site continues to benefit from Varnish cache on Acquia balancers. The transition to activate or deactivate the CDN is seamless and causes no downtime. The traffic route change leaves site content, databases, and files unaffected.

Cache and Purge Behavior

The CDN cache becomes unavailable when you deactivate Platform CDN. Expect slightly higher response times until the Varnish cache on Acquia balancers is fully warm. When you activate Platform CDN, the CDN cache starts empty and warms up as visitors access the site.

If you deactivate Platform CDN, the platform switches cache purge operations from the CDN purger to the Varnish purger. The site continues to display content updates without manual changes to Drupal purge configuration.

Affected Domains

The configuration to deactivate Platform CDN applies to all domains associated with a site simultaneously. The platform does not support a configuration to deactivate the CDN for only the CMS domain. 

The action applies to the following domain types:

When Platform CDN is inactive, all domains for the selected site route directly to Acquia balancers.

Managing Platform CDN for a site

Platform CDN is active by default for all Source CMS sites.

Disabling Platform CDN

To disable Platform CDN for a site:

1. Log in to Source CMS to open the Sites Dashboard.
2. On the Sites tab, locate the site to deactivate Platform CDN.
3. Click the title of the site. 
4. In the left navigation, click Domains & SSL. 
5. Next to View DNS information and Add Domain, click the Ellipses (...) icon.
6. Select Disable CDN.

7. In the confirmation dialog box, review the impact summary and select Disable CDN.

   DNS propagation typically completes within 30–60 seconds. During this timeframe, some requests can still route through Platform CDN until propagation finishes.

After you select Disable CDN, the following actions occur automatically:

• The platform updates DNS records to route traffic directly to Acquia balancers.
• The platform switches cache purge operations from Platform CDN to Varnish.

• The platform maintains Secure Sockets Layer termination for all Acquia-managed domains.

  Note

  If the operation fails, the site remains in its previous state. Verify the Sites Dashboard for error details, and run the operation again. If the issue persists, contact Acquia Support.

Activate Platform CDN

To re-enable Platform CDN for a site:

1. Log in to Source CMS to open the Sites Dashboard.
2. On the Sites tab, locate the site to re-activate Platform CDN.
3. Click the title of the site. 
4. In the left navigation, click Domains & SSL.
5. Next to View DNS information and Add Domain, click the Ellipses (...) icon.
6. Select Enable CDN.

7. In the confirmation dialog box, review the impact summary and select Enable CDN.

   The system restores CDN routing and switches cache purge operations back to Platform CDN. DNS propagation typically completes within 30–60 seconds.

Custom Domain DNS Configuration

The DNS information for custom domains changes when Platform CDN is disabled. The Sites Dashboard updates the DNS Records modal automatically to display the correct target. Acquia-managed domains update automatically, but you must update custom domain records with your DNS provider to match the target shown in the Sites Dashboard.

To verify or update DNS records for custom domains:

1. Log in to Source CMS to open the Sites Dashboard.
2. On the Sites tab, locate the site to re-activate Platform CDN.
3. Click the title of the site. 
4. In the left navigation, click Domains & SSL.
5. On the Domains tab, select View DNS Information for the relevant domain.
6. Note the updated DNS target records displayed in the modal.
7. Update the DNS records with your DNS provider to point to the target shown.

Implementation Scenarios

If you suspect that performance degradation or errors originate from the CDN layer, disable Platform CDN to isolate the issue.

To troubleshoot performance issues:

1. Disable Platform CDN for the affected site.
2. Verify whether the issue persists without the CDN layer.
3. Report the CDN-specific behavior to Acquia Support if the issue resolves.
4. Activate Platform CDN after you complete the investigation.