Platform cache functionality, including remote synchronization, is part of the Optimizely platform.
Classes in this topic are in the Mediachase.Commerce.Catalog namespace.
## Cache subsystem
Caching for each subsystem, such as catalogs and orders, is configured in its respective configuration files. For a catalogs example, see _ecf.catalog.config_ in the site's _configs_ folder.
**Example:** Cache settings for the Catalogs subsystem
The collectionTimeout responds to an entry array, and "entry" responds to a single entry. What is actually cached is the CatalogEntryDto and, because the Entry object is created from the Data Transfer Object (DTO), you cache the DTO. In some cases, you also can cache the entry objects themselves rather than the DTO.
## Cache invalidation
In the Catalogs subsystem example, the cache is invalidated if it reaches the cache timeout specified above (0:1:0) for the request type or if an object is updated. You also can invalidate cache for the entire catalog by calling CatalogCache.Clear().