Entity Tags (eTags)

When designers open a design, they should always have the latest version of that design, regardless of who has worked on it previously inside the larger business workflow. Similarly, when designers use a print template, they should always be using the most recent version of that template. To accomplish this, Designer XI uses entity tags, commonly called eTags. This mechanism is widely used in HTTP traffic as a caching and performance improvement strategy.  Designer XI’s use focuses on the caching aspect.

How eTags Work

The Storage Service holding the design file or template keeps a unique identifier that changes any time a modified file gets uploaded, regardless of the data’s origin.  When a client machine opens a cached design, it provides the eTag it contains for the design and template files to the Storage Service. If the service has a different value, the client machine knows it doesn’t have the latest version of the file.  A new copy is downloaded and then opened.  When the eTags match, nothing is downloaded and the client opens its local copy.

For this eTag comparison to function, the Designer XI application must be online and the Storage Service must be accessible. However, if the user is offline or if the service is inaccessible, the client application uses the local file.