So far we learned about Apache Ignite architecture, caching styles, and clustering topology. Caching can be used in the UI layer to serve static content, and a JVM-level local cache can be configured to access the frequently used objects or query results. However, a distributed cache can act as an in-memory data store and move the data closer to the application. The data grid is an abstraction of a distributed cache as a data store. In this chapter, we will explore Apache Ignite's data grid concept and build a highly available web application with Ignite Session Clustering. All user sessions will be stored in a data grid and we will use the Ignite tools to view the user sessions in the grid. The following topics will be covered:

• Exploring the Data Grid
• Configuring the Data Grid
• Web Session Clustering