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In SharePoint 2013 there is a new service called distributed catch. The Distributed catch service is built on windows AppFabric, which implements the AppFabric catching service window server AppFabric installs with the prerequisites for SharePoint Server 2013.

The Distributed Cache service provides in-memory caching services and does not have a dependency on databases for several features in SharePoint Server 2013. Some of the features that use the Distributed Cache service include:

• Newsfeeds
• Authentication
• OneNote client access
• Security Trimming
• Page load performance

When the service is enabled, these features use the Distributed Cache for quick data retrieval. Blob Cache and Output Cache do not use a distributed caching service since these types of cache exist on each Web Front End server in the farm.

Example

• The feed queries the Last Modified Time Cache to retrieve time stamp information and metadata of recent activities.
• This information is then used as input to query the feed cache to retrieve activity data.
• The requested feed is then constructed by using the activity data retrieved from the Feed Cache.

For each entity, the feed cache assigns a portion of memory known as a cache bucket to store recent activity data for that entity. Entities include users, tags, sites, and documents. Cache buckets only store recent activities. Many cache buckets will be empty because not all entities will have recent activities. By default, recent activities are kept for seven days.