This primer describes the underlying principles of data in memory, partitioning, and caching, and then describes WebSphere eXtreme Scale fundamentals in these terms. Use cases are included to show how these underlying principles result in business benefits.. Introduction What is IBM WebSphere eXtreme Scale and how does it work? Let’s take a two-pass approach to answer this question. First, an explanation as you might find it in the Information Center: WebSphere eXtreme Scale operates as an in-memory grid that dynamically processes, partitions, replicates, and manages application data and business logic across hundreds of servers. It provides transactional integrity and transparent fail-over to ensure high availability, high reliability, and consistent response times. WebSphere eXtreme Scale is an essential distributed caching platform from IBM for elastic scalability and the next-generation cloud environments. Elastic means the grid monitors and manages itself, allows scale-out and scale-in, and is self-healing by automatically recovering from failures. Scale-out allows memory capacity to be added while the grid is running, without requiring a restart. Conversely, scale-in allows on-the-fly removal of memory capacity. Got that? If not, let’s look at an example and try again to explain what this groundbreaking product is all about. Quite simply, the goal of WebSphere eXtreme Scale is to dramatically improve application performance. As the name suggests, one of its primary objectives is to dramatically scale-up the number of users that an application can support. This scale-up could be to serve more users in less time, or to serve many more users with reasonable, predictable response times. Read More ... Follow us on Twitter @ WebSphereXTP