GigaSpaces Terminology (Magic xpa 4.x)

Data Grid – The in-memory data grid is middleware software composed of multiple server processes running on multiple machine instances (physical or virtual). These processes work together to store large amounts of data in memory, thereby achieving high performance, elastic scalability, and fail-safe redundancy.

Space – A Space is a data and business logic container that stores data objects in memory (similar to a database instance) and runs in the data grid. A data grid can contain multiple Spaces. However, Magic xpa uses a single Space for running multiple projects. For redundancy and scalability, data and business logic in the Space are replicated and partitioned across all machines participating in the data grid, ensuring continuous service even during machine or software failure.

Processing Unit – The Magic processing unit is a software module that runs in the data grid and has direct access to all data in the Space. Magic xpa includes a processing unit component that handles administrative and housekeeping operations such as startup of engines, monitoring, and recovery tasks.

Grid Service Agent (GSA) – This is a GigaSpaces entity that acts as a process manager that can spawn and manage Service Grid processes such as the Grid Service Manager (GSM), the Grid Service Container (GSC), and the Lookup Service (LUC). This agent can be installed as an operating system process. It runs on a specific machine and is responsible for adding that machine to the grid, monitoring grid processes on its own machine, and restarting them in case of process failure.

Grid Service Container (GSC) – A container that hosts processing units or Space partitions.

Grid Service Manager (GSM) – The service that manages the Grid Service Containers. The GSM deploys and undeploys processing units to the grid. The GSM monitors the processing units running within each GSC.

Lookup Service (LUS) – A registry that contains information as to where each loaded component is actually situated.