Read-Through and Write-Behind (AppFabric 1.1 Caching)
Microsoft AppFabric 1.1 for Windows Server provides the architecture to create and use read-through and write-behind providers. These providers provide integration with a backend store, such as a database. To create a read-through or write-behind provider, you must create an assembly that implements the DataCacheStoreProvider abstract base class. The assembly is then associated with a cache using new parameters of the New-Cache and Set-CacheConfig Windows PowerShell commands.
If an item doesn't exist in the cache, a call to DataCache.Get will return
null. In the cache-aside programming model, the caller is responsible for then loading the data from a backend store and then putting that data in the cache. With a read-through provider, the cache detects the missing item and calls the provider to perform the data load. The item is then seamlessly returned to the cache client.
In the same way, items that are added or updated in the cache can be periodically written to the backend store using a write-behind provider. This happens asynchronously and on an interval defined by the cache.