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Check CDN operation
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Check CDN operation

warning

We are discontinuing support for the Akamai provider. Creating new Akamai CDN resources is not available, existing Akamai resources will cease to function and will be deleted on May 1, 2025. We recommend switching to a Selectel provider now to avoid website outages. To connect Selectel CDN, please use the instructions in the following section Connect CDN.

If there are errors or slow download speeds of content via CDN, check:

Check balance⁠

  1. В control panels go to CDN → CDN resources.
  2. Look at the account balance in the upper right corner and the status of the CDN resource. If the balance is negative and the CDN resource is in status DOWNthen the CDN resource was shut down for non-payment.
  3. To enable a CDN resource, top up with the amount owed, then share.

Check CDN resource⁠

The check will show the status of the CDN resource, the correctness of the CNAME record and the availability of the file from the content source and CDN server.

  1. В control panels go to CDN → CDN resources. Check it out status in the CDN resource string. If the resource is in the status ERROR or hovering in one of the statuses, file a ticket.

  2. Open the file on the content source using a link of the form example.com/images/image.png. If the file doesn't load, the problem is on the side of your site.

  3. Open the file through the default domain using a link of the form *.selcdn.net/images/image.png. Default domain can be viewed in control panels: section CDN → CDN resources → resource page → tab General. If the file does not load, check Host header.

  4. Open the file through your personal domain using a link of the form cdn.example.com/images/image.png. Personal domain can be viewed in control panels: section CDN → CDN resources → resource page → tab General. If the file does not load, check if the file is correct resource record of the domain.

Check content loading speed⁠

The first access to the content source takes longer to download the file than subsequent accesses when the file is distributed from the cache.

  1. Make sure the device you'll be checking from has VPN or proxies turned off — they can slow down download speeds.

  2. Check the download speed on the content source:

    2.1 Open the file on the content source.

    2.2 Check the download speed of the file by opening the developer tools in your browser → tab Network → see the value in the column Time.

  3. Upload the file to the CDN cache, to do this open the file on the domain which is used to distribute content via CDN. The domains can be viewed in control panels: section CDN → CDN resources → resource page → tab General.

  4. Check the download speed from the CDN cache:

    4.1 Re-open the same file you opened in step 3 on the CDN domain.

    4.2 Check the download speed of the file by opening the developer tools in your browser → tab Network → see the value in the column Time.

  5. Compare the download speed of the file from the source and from the CDN cache. If the CDN download speed is higher or equal to the source download speed, the CDN is working correctly. If the CDN download speed is lower, leave a diagnostic request.

Leave a request for diagnostics⁠

  1. Record the HTTP session demonstrating the CDN error in HAR file format. For more information about recording a HAR file for Edge, Firefox, or Chrome, see the instructions How to get a HAR file of the Google Admin Toolbox portal.

  2. Create a ticket with a request for diagnostics. Specify in the ticket:

    • CDN resource name;
    • a link to a file on the domain that is used to distribute content via CDN;
    • HAR file that you created in step 1;
    • mass of requests with the problem and the location of users who have the problem.