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Oracle Coherence is a product that can be used for application clustering and reliable data sharing, caching state in the Application tier and relieve load on lower-tier systems such as databases, mainframes, Web Servers, or Web Services.

Coherence is used for a so called Data Grid. A Data Grid is a system composed of multiple servers that work together to manage information and related operation.

Coherence can be used for the following cases:

• Caching: Applications request data from the Data Grid rather than backend data sources

• Analytics: Applications ask the Data Grid questions from simple queries in advanced scenario modeling

• Transactions: Data Grid acts as a transactional System of Record, hosting data and business logic

• Events: Automated processing based on events Integration with Coherence can be achieved by Custom integration through the Coherence API or through existing Switch-On out-of-the-box integrations such as:

• TopLink Grid in combination with JPA object-relational data. This simplifies Coherence use in shared database environment and propagates DB updates to Coherence. GoldenGate captures the changes to database tables and TopLink maps database changes to cached.

• WebLogic Server: In-memory HTTP session on Grid.

• Service Bus: Service Result Caching. Result caching is controlled at business services level and allows for fine-grained control for composite services. It caches the same set of services being called many times so it doesn’t have to go over the line again, which gives better performance.

A subset of results will make up final results of a cached service. Coherence in Exalogic uses direct memory access and bypasses the kernel to improve speed and performance. The newest version of Coherence ( 3.7.*) has ActiveCache integration with WebLogic Server. It has Coherence cluster MBeans within WebLogic Server.

The Node Manager is enhanced for starting/stopping Coherence cache servers from the Administration Console or doing it remotely.

Coherence supports Java APIs and Exalogic Elastic Cloud Software and has focused on Exalogic with the following features:

• Enable low-latency computing

• Optimized implementation for Exalogic Infiniband