Clear eCDN Cache

B2C Commerce gives you the option to cache static storefront content (images, icons, CSS style sheets, and other non-dynamic assets) in eCDN cache or the web tier static content cache.

The web adapter configures web pages using static assets from both eCDN and web tier cache sources. Regardless of the cache location, web tier or eCDN, each static content asset on your storefront is assigned a fingerprint value. For example, In this URL,

https://www.samplecustomer.com/dis/dw/image/v2/XXXX_PRD/on/demandware.static/-/Sites-customer-master/default/dwabb3a337/images/hi-res/shoes.jpg?sw=200=200=fitm=png>.

dwabb3a337 is the asset fingerprint. The fingerprint provides a unique identifier for the asset. Updates to static cache occur at intervals you set. If necessary, you can update an asset held in static cache before the cache interval expiration. The process does not require cache to be cleared, and can be completed without requesting a support ticket.

  1. Upload the updated asset to your storefront POD.
    When an asset is updated on the POD, the system generates a new fingerprint value for that asset. Changing the fingerprint also changes the URL of the updated asset. When your storefront requests the updated static asset, the URL request returns a miss in eCDN and web tier cache because the finger print is different and the CDN doesn’t see the new and old asset as the same one. The missed request with the new fingerprint is then directed to the POD, and the asset is retrieved, and cached with the new URL.
    Note: All content assets in cache are refreshed, excluding the old content updated in this process. The update content is assigned a new fingerprint that results in a new URL for the asset.
  2. Refresh your site, and in your browser confirm the updated asset is shown as expected.

eCDN Users

eCDN uses the Cache-Control header to persist a file in their cache until that TTL expires. When the cache header expires, eCDN retrieves the new resource.

eCDN caches based on the value set by the cache headers. If these headers are not set, the default value of 30 days is enforced.

Troubleshooting

Process errors are rare and mean something went wrong with the cache clear process. If the updated asset does not show in your browser after updating content, you can manually invalidate the application tier cache.

  1. In Business Manager > Administration > Sites > Manage Sites > Cache determine the level, page or storefront, for which you want to clear the cache, and click Invalidate cache.
    The system rebuilds cache from the POD assets, and assigns new fingerprints to the updated assets.
  2. Refresh the site in your browser, and confirm the updated asset is shown as expected.