CDN basics
Cloudimage caching and invalidation
Cloudimage leverages Content Delivery Networks to accelerate the delivery of your images worldwide. We work with multiple CDN providers to optimise the delivery of your images and provide superb reliability.
In addition to accelerating your images, the CDN provides DDoS (Distributed Denial of Service) protection, which will act as a shield to your servers and avoid any downtime.
CDNs cache images for faster delivery. They usually keep assets cached as long as it is stated in the caching directive. When the original image changes, the CDN wonβt automatically detect that, so you need to either change the image URL or invalidate the cached version.
Invalidation
To refresh your images, you can either update the Cloudimage URL or invalidate them to flush them from the resizing servers and the CDN.
Option 1: add version parameter to the origin URL to force the CDN to download the new image
Old image:
//doc.cloudimg.io/sample.li/flat.jpg?w=500
New image:
//doc.cloudimg.io/sample.li/flat.jpg?w=500&vh=xx (where 'xx' represent random numbers)
Option 2: invalidate images from the Admin panel
If you cannot change the image URLs when changing the origin image, you can still invalidate (flush) the image from the Cloudimage admin console. Log in to the console and navigate to Invalidation, or go to this page - https://admin.cloudimage.io/project/invalidation
First, you need to select the scope of the Invalidation:
Original -> targets specific image URLs. Enter up to 10 URLs, separated by commas or line breaks.
All -> this option will erase the entire cache generated for your token. Please use it with caution, because after invalidation, the cache needs to be rebuilt, and your first requests would take more time for execution.
Do not use the full path of your image but only the origin_image_url part as invalidation path.
For example, to invalidate doc.cloudimg.io/sample.li/flat1.jpg?w=500
, you need to input /sample.li/flat1.jpg
.
This will remove the image(s) from all CDN nodes and Cloudimage resizing servers.
When the Invalidation request is submitted, it appears in the Invalidation log. Both manual and automatic invalidations are logged there.
Details of the Invalidation Log
Every request has the following parameters:
Status - the status of the request:
Received - request received successfully
Preparing - the Invalidation server prepares the request for execution
Flushing Scaleflex servers - deleting the cache in the resizing servers
Flushing CDN servers - deleting the cache of the CDN servers
Done - the invalidation finished successfully
ERROR_CDN_NODE - error in the CDN invalidation step
ERROR - general error in some of the invalidation steps
Scope - the scope of the request (original / all)
Date - the datetime when the request has been submitted for execution. The value is in the local time zone.
Invalidation ID - the unique identifier of the request.
Invalidation path - if you click on "See links", you can inspect which URLs have been requested for invalidation (applicable for the invalidations with scope "original")
Retry - resend the invalidation request if it failed.
Click the Refresh button to reload the invalidation log and view the latest updates.
Option 3: use the Invalidation REST API
You can also automate invalidations by calling the Invalidation API. This is useful for developers managing large-scale projects or CI/CD workflows.
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