Oracle Coherence is a high-performance, distributed data grid and caching solution designed to improve the scalability and reliability of enterprise applications. As an in-memory data grid, Coherence stores data in memory for faster access and processing than traditional disk-based databases. Oracle offers several editions of Coherence, including Oracle Coherence Enterprise Edition and Oracle Coherence Grid Edition, which include advanced features to meet different scalability and management needs. The technology supports multiple data formats, including the Portable Object Format for efficient data storage and retrieval.

Oracle Coherence is primarily used to manage large volumes of data across distributed systems in a fault-tolerant manner. It serves several use cases:

• Data Caching: By caching data in memory, Coherence reduces the load on databases and provides faster access to frequently used data.
• Session management: In web and application server environments, Coherence handles HTTP session management, improving the scalability and reliability of web applications.
• Data Grid: Coherence acts as a data grid, enabling shared management of data across multiple processes and applications, ensuring data consistency and real-time access.
• Scalability Solutions: Helps scale applications across multiple data centers and clusters, manage data replication, and ensure continuous availability.
• Real-time data processing: Coherence supports in-place processing with features such as Coherence Events, enabling applications to dynamically and instantly respond to data changes.
• Custom application development: It starts with setting up a storage-enabled Coherence server to ensure that custom applications can insert and retrieve data efficiently, running seamlessly with the HelloCoherence application for optimal data management.

At its core, Oracle Coherence creates a network of cluster members that share and manage data. Each cluster member can access and modify data stored in the Coherence data grid as needed. Data is managed in a distributed fashion across multiple clusters and applications, ensuring high availability and fault tolerance. Learn how does Coherence work in detail:

• Cluster Services: Coherence uses cluster services to manage the network of nodes that make up the grid. Each service is responsible for a specific aspect of data management, such as caching or event handling.
• Data storage and access: Data is typically stored in the form of Coherence maps that are distributed across the cluster members. This ensures that data is available close to where it is used, improving performance and reducing latency.
• Data replication and backup: To prevent data loss, Coherence automatically backs up data across multiple cluster members. If one member fails, data can still be retrieved from another member.
• Coherence Configuration: Using XML configuration files and specific deployment descriptors, users can tailor Coherence setups to meet specific requirements, including defining the data model, setting up Coherence clusters, and configuring the network.
• Integration and Extensions: Coherence can be extended with additional features such as REST APIs for data access, integration with Maven projects for build management, and support for Kubernetes operators for orchestration in cloud environments.