Discovering and fixing image delivery issues

If you have a modern website or mobile app, there’s no doubt you deal with a lot of media resources, particularly images. But delivering these images can be a challenge. You may not know if there are broken images on your website, or if URLs point users to non-existing images, resulting in HTTP status errors. Worse yet, search engines like Google, may have indexed the URLs of images that have since been deleted or modified, leading to even more errors when users try to access them.

So, how can you discover and identify these errors when you don’t have clear visibility into your system and analytics tools, like Google Analytics, are unable to help you find them? One good way is to use an image management solution that offers image delivery error reporting. When looking for a solution to help with this problem, you’ll want to make sure that it offers a centralized management console from which you can quickly and easily see detailed error reports. 

[pullquote]Any issues involving the correct building of image URLs… can be identified, debugged and fixed before your users ever notice.[/pullquote]

An error report should list all the resource delivery errors for the current date (by default), as well as the number of errors by the type of error encountered. Another helpful feature is graphing capabilities, which can show the frequency of each type of error over a given period of time. Search capabilities are valuable as well, enabling you to retrieve the total number of errors for a specific date. 

Among the types of errors you may find include: 

• 400 Bad Request: The server cannot process the request due to something that is perceived to be a request error. The cause could be malformed request syntax or invalid image transformation parameters.
• 401 Unauthorized: Authentication is required and has failed, or has not been provided. For example, the URL should be signed when using add-ons or for certain transformations in Strict Transformations mode, or the image type was restricted in your account’s security settings.
• 404 Not Found: The requested resource could not be found, meaning the public_​id is invalid.
• 408 Request Timeout: The server timed out waiting for the request. This could be the result of a networking error or a slow client.
• 420 Rate Limited: There may either be too many concurrent requests for images, or the hard quota for add-on usage for your account was exceeded.
• 200 Fallback image on error: A default image placeholder was delivered as the requested image was not found.

When looking at an error report, you should be able to select one of these error categories, then see the list of errors encountered within that category and the details associated with that error, such as the reason for the error, the URL of the requested image and the referral web site (who is requesting the resource).

The information contained in error reports should be useful in pointing out issues with image delivery, and displayed in near real time. Besides the report’s usefulness in identifying and fixing issues with resource delivery on an ongoing basis, an error report can help when you first implement an image management solution, as well as when you launch your site or application in production or update it. Any issues involving the correct building of image URLs, or inadvertently breaking any image deliveries, can be identified, debugged and fixed before your users ever notice.

With an error reporting feature, you will be able to gain a lot of useful information and insight about your image and video delivery, and analyze problems associated with delivering your media. The report enables you to quickly locate the problems, debug and analyze the issues, and then fix them.