Federated Portal Caching
The functionality described in this topic does not apply to an SAP NetWeaver Composition Environment system without usage type EP Core - Application Portal (EPC).
SAP NetWeaver Portal provides a dedicated caching service, FederatedPortalCache , for the federated portal scenario. Its primary purpose is to reduce network traffic to the producer by storing semantic objects on the consumer side for reuse.
The caching service is based on Cache Management Library (CML) cache, which is a centralized cache management infrastructure. The federated portal uses a dedicated region in the cache. The cache stores semantic objects, such as iViews, pages, layouts, and roles, which are transferred from producer to consumer.
You specify the object cache validity period. If a requested object is cached and is within its validity period, the consumer reuses the object instead of performing a call through the network to the producer.
Example of cached information in a federated portal:
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With remote role assignment usage, a role and its navigation structure are cached at runtime when a user on the consumer requests the role from the producer.
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With remote delta link usage, a consumer caches the shared areas within the producer's Portal Catalog structure, thereby improving the browsing experience of the remote Portal Catalog.
Caching in a Clustered Environment
The federated portal caching service provides persistency on top of the memory cache, thereby providing support for a clustered environment. The persistent cache acts as a repository for the memory cache of the nodes of the cluster. In a clustered environment, each server has its own cache, including memory cache, and all servers (nodes) share persistency in a single database. When a server retrieves updated objects from the cache, they are immediately updated in the central database and are available to all servers in the cluster without the need to go through the network again.
Persistency can also be used to make cached objects available after restarting the portal server and to provide the capacity for storing a large number of semantic objects, which standard memory would not typically be able to handle in a production environment. For example, when the portal retrieves a role at runtime through remote role assignment , consider the number of objects each role contains and multiply that by the number of concurrent users served by each role.