ELIS - Alfresco Learning Object Repository 1.9 Manual

Tuning the Repository

The Cache files setting in the Repository can be used to improve repository performance.

Cache settings

By default, repository files are not cached in the user's browser due as this may prevent users from seeing the most recent version of the file. However, this can cause performance issues as users must download the file each time they view it. The repository also must check each time the user downloads a file to be sure they still have access to that file. These two features of the repository can slow down the delivery of files to the viewers.

To alleviate this situation, we have implemented a file caching setting. This enables you to specify a period of time that the files will be cached in the user's browser. When the user views a file that they have cached, the file loads much faster as it loads from their computer rather than being delivered the Internet.

For sites where files that are stored in the repository are frequently changed or updated (every few minutes), it is best to use a low setting or leave caching off, this will mean it will take longer for viewers to load files from the repository, however it will also ensure that they always see a recent version of the file.

For most sites, repository content changes with a lower frequency, and a larger caching setting can be used, for instance 30 minutes. Remember that if a viewer views file A, then file A is changed, a 30 minute cache time means that the viewer who has already viewed file A in less than 30 minutes since it has changed, will see the old version until the caching time is up.

If users complain that they don't see the latest version of a file, you can set your repository cache file to a lower number, or just inform them to clear their cache and refresh their browser page if they are unsure of the recency of the file.