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Configure caching
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Configure caching

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 in May 2025. We recommend switching to a Selectel provider now to avoid website outages. To connect Selectel CDN, please use the instructions in the section Connect CDN.

Customize cache lifetime⁠

When a file is cached, the cache lifetime — the period in which a CDN server or browser gives users a cached version of the file without accessing the source — begins to run.

When the cache lifetime expires, the CDN server or user's browser compares the versions of the file in the cache and at the source — if the versions differ, the file in the cache is replaced with a fresh version from the source. If the versions are not different, the file in the cache remains the same. The cache lifetime for this file in both cases starts anew.

If a file in the cache has not been accessed for more than 36 hours, it is automatically deleted from the cache, even if its lifetime has not yet expired. The file will be reloaded into the cache only if it is requested by the user.

You can customize the cache lifetime on CDN servers and in the user's browser.

To change the cache lifetime:

  1. in control panels from the top menu, press Products and select CDN.

  2. Open the CDN resource page → tab Settings.

  3. Open the card Content.

  4. Select the maximum cache lifetime on CDN servers:

    • If you select a time period, the CDN server will access the source at the end of each such period;
    • if you choose Use source settings, the cache time will be equal to the time that is set on the source in the header Cache-Control. If the header is not set, the content will not be cached.

  5. Select the cache life time of the browser:

    • if you select a time period, the browser will access the source at the end of each such period;
    • if you choose Use browser settingsThe cache time will be equal to the time set in the browser settings.

  6. Click Save.

CDN caches one file with different cookies from the HTTP request header Set-Cookie as different files, and each new client request is proxied to the source. Ignoring Set-Cookie allows you to cache a file with different cookies as a single object.

  1. in control panels from the top menu, press Products and select CDN.
  2. Open the CDN resource page → tab Settings.
  3. Open the card Content.
  4. Check the box Ignore Set-Cookie.
  5. Click Save.

Ignore request parameters⁠

If requests for the same file contain different parameters (the part after the question mark in the file URL), each request with a new parameter is proxied to the source. Ignoring request parameters allows caching files with different request parameters as a single object.

  1. in control panels from the top menu, press Products and select CDN.
  2. Open the CDN resource page → tab Settings.
  3. Open the card Content.
  4. Check the box Ignore request parameters.
  5. Click Save.

Give cache on source errors⁠

This option allows you to retrieve the last cached content if the source responds with an error. At the moment of the error, not all site data may be in the cache — for example, not all images, videos or stylesheets. In this case, the site pages may not be displayed in full.

If the source responded with an error when requested, CDN servers will check its availability with each new request:

  • if the error persists, CDN servers will give the last cached content with the header Cache: Staleuntil the cache life time expires;
  • if the source functionality is restored, the CDN will cache a fresh version of the file.

To enable cache giveaway on source errors:

  1. in control panels from the top menu, press Products and select CDN.

  2. Open the CDN resource page → tab Settings.

  3. Open the card Content.

  4. Check the box Always online.

  5. Select the errors in which to give the last cached content:

    • Error (network issues)
    • Timeout (response time should not exceed 5 seconds)
    • Invalid Header
    • updating (cache update)
    • Error 500
    • Error 502
    • Error 503
    • Error 504
    • Error 403
    • Error 404
    • Error 429

  6. Click Save.