Add an origin group to a CDN resource

Origin groups define the content sources for a CDN resource and support load balancing and failover across multiple origins.

Origin group overview

One origin group can contain a single website, private bucket, or FastEdge HTTP application, or multiple origins.

With multiple active origins, the CDN distributes requests using a round-robin algorithm. Backup origins handle requests when an active origin returns a 5xx error, which increases fault tolerance.

Step 1. Add a new origin group

Create an origin group during resource creation, from an existing resource, or on the Origin groups page.

In resource settings

Add a group while configuring an existing CDN resource.

1. Open the resource settings

   In the Gcore Customer Portal, navigate to CDN, find the resource, and click its CNAME.

   
2. Open the origin group form

   In the Origin pull protocol section, click Add group.

   

On the origin groups page

Groups created on the Origin groups page must be attached to a CDN resource after creation.

1. Open the origin groups page

   In the Customer Portal, navigate to CDN > Origin groups.

   
2. Open the creation form

   Click Add origin group.

Step 2. Enter the origin group name

Enter a unique Origin group name.

Step 3. Configure the origin group

Add one or more origins to the group. For URL and S3 origins, Host header override is optional; when left empty, the CDN uses the Host header value from the CDN resource settings.

S3 storage

Select Amazon for Amazon S3 or Other for another S3-compatible storage service.

Without Origin Shielding, each cache miss on a CDN node sends a request directly to the S3 bucket. At scale, this can overload the storage cluster — enable Origin Shielding to route cache misses through a single shielding node and reduce S3 load.

Amazon S3 storage

Amazon S3 requires an access key ID and secret access key; the AWS guide explains where to find both values.

1. Select Amazon S3

   Select S3 storage, then select Amazon.

2. Configure the bucket

   Enter the storage details:

   1. Enter the Access Key ID.
   2. Enter the Secret access key.
   3. Select the AWS region where the bucket is hosted.
   4. Enter the Bucket name.
   5. (Optional) Enter the Host header override.

   

Other S3 storage

Other S3-compatible services require the storage hostname, credentials, region, and bucket name.

1. Select another S3 service

   Select S3 storage, then select Other.

2. Configure the bucket

   Enter the storage details:

   1. Enter the storage server Hostname.
   2. Enter the Access Key ID.
   3. Enter the Secret access key.
   4. Enter the Region where the bucket is hosted.
   5. Enter the Bucket name.
   6. (Optional) Enter the Host header override.

   

URL origin

Use a URL origin for a website or IP address that doesn’t require S3 authentication.

1. Select the origin type

   Select URL.

2. Configure the origin

   Enter the origin details:

   1. In Origin source, enter the IP address or domain name without http:// or https://.
   2. (Optional) Enter the Host header override.
   3. (Optional) For ports other than 80 or 443, disable Use default port and enter the port.

   
3. Add more origins

   (Optional) Click + Add origin and enter another source. The CDN distributes requests across active origins using a round-robin algorithm.

FastEdge HTTP application

A FastEdge HTTP application can serve as a native CDN origin. Requests reach the application directly on the same edge node, which avoids duplicate response headers, preserves client GeoIP data, and reduces latency.

1. Select the origin type

   Select FastEdge.

2. Select the application

   In the FastEdge application dropdown, select the HTTP application.

   

Available options

Set up multiple origins

For groups with multiple origins, configure their availability, roles, and failover behavior:

• Enable or disable each origin.
• Assign active and backup origins.
• Enable or disable Use next upstream.

Enable or disable an origin

Each origin has the On toggle enabled by default, so the CDN can pull content from it. Disable the toggle to remove the origin from this group’s load balancing; requests stop reaching it within 15 minutes.

At least one active origin must remain enabled.

Activate origin or use it as backup

New origins receive the Active status by default and participate in round-robin load balancing. Select Use origin as a backup to remove an origin from regular balancing and use it when an active origin returns a 5xx error.

Use next upstream

Enable Use next upstream only when every origin contains the same content. The CDN then tries subsequent origins after eligible 4xx or 5xx responses, except code 400; if no origin succeeds, it returns the final origin’s response.

The resulting request behavior depends on the origin roles and option state:

Case	CDN request behavior
Use next upstream is disabled; all origins are active	The CDN returns an active origin’s error response to the client
Use next upstream is enabled; one origin is active and the rest are backups	After a 4xx or 5xx response, the CDN tries the remaining origins in list order
Use next upstream is enabled; all origins are active	After a 404, 500, 502, 503, or 504 response, the CDN tries the remaining origins in list order
Use next upstream is disabled; one origin is active and the rest are backups	After a 5 s timeout or 5xx response, the CDN tries a backup origin. For a 4xx response, it returns the error to the client

Step 4. Save changes

Click Add group.

Step 5. Attach the origin group

Changing a resource’s origin group doesn’t update its Host header. Update the Host header separately.

Attach a group created from the Origin groups page to its CDN resource.

1. Open the resource settings

   In the Customer Portal, navigate to CDN, find the resource, and click its CNAME.

2. Select the origin group

   In the Origin section, select the group from the Origin group dropdown and click Add group.

   
3. Save the resource

   Click Save changes.