Abstract

Orthogonal persistence provides the programmer with persistence for all data types, with minimal impact on the programing model or development process. We motivate the addition of orthogonal persistence to the Java ™ platform, and show how this results in a simple and appealing application development model. The overall goal is to provide the illusion of continuous computation in the face of system shutdowns, planned or unplanned. This is achieved by checkpointing the state of the system periodically to stable memory. We describe how the principles of orthogonal persistence are applied to the Java ™ programming language and specify the small set of changes to the Java language specification and core libraries necessary to fulfill these principles. We describe the rationale for our particular choices, informed by the experience with the PJama prototype implementations. Finally, the programming model for managing state that is external to the Java ™ virtual machine is discussed in detail.

Citations