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Documentation & User Guides | FotoWare

Choosing a cache folder for thumbnails and previews

Why the cache folder is important

Index Manager creates and stores a low-resolution copy of the thumbnails and previews that it serves to the clients. This helps speed up the system since the server does not need to generate a new thumbnail and preview the next time a client requests a file that is in the cache. Caching is a major factor in optimizing system performance, and a large cache stored on a fast, local drive (with a large disk cache as well) is the key to building a responsive, high-performance FotoWare system.

Choosing a cache folder and the max cache size per index

If you would like to change the default cache folder, open the Index Manager configuration and go to Service Options. Then click on the General tab.

Use the Browse button (...) to select another folder than the default one. We recommend placing the cache folder on the fastest available local drive. NEVER store the cache on a network volume - it needs to be on a local disk.

Max cache size per index: This setting controls the maximum size of each index cache in megabytes. The cache can grow larger than the limit set here on a daily basis (learn why), but it will be reduced to the set size during the scheduled index optimization at which point the oldest cached items will be removed. Since caching is so crucial to maintaining solid system performance, you should consider storing the cache folder on a disk with much available space to allow the cache to expand.

Index Manager cache folder settings

Learn more about caching and its effect on system performance.

Consider the following when choosing a cache folder

The cache folder should be placed on the fastest possible local disk, with plenty of available space to limit file fragmentation. Thumbnails generated by Index Manager occupy some 10-15Kb each, while each preview typically occupies 100-150Kb.

The Index Manager process account set in the Operations Center must have access to read and write to the folder you choose as your cache folder.

As explained above, the index cache may grow beyond the size limit that you set in the configuration but will be reduced during index optimization. Keep this in mind when choosing a cache drive.

If, after some time of operation, you find that the log frequently reports that that cache size limit has been reached and cache warming has stopped, you may consider increasing the size of the index' cache folder.

Changing the location of an existing cache folder

Note that when running FotoWeb on Internet Information Services (IIS), after changing the cache folder in FotoWeb you also need to update the virtual directory for the cache folder in IIS to the correct location. This can be done through the IIS management console.

Caching and Color Management

When Index Manager creates thumbnails and previews for the image cache, it will honor the ICC profile that is present in the file. However, if the image does not have an embedded ICC profile, Index Manager will assume that the picture should be rendered with sRGB. This will have a negative impact on the thumbnail quality if the pictures are indeed in Adobe RGB even if they are not tagged with that profile.