Fault-tolerance: Java's Missing Buzzword 2.1 Fault-tolerance and Nondeterminism

Java has been described as a simple, object-oriented, distributed, interpreted, robust, secure, architectural neutral, portable, high-performance, multithreaded and dynamic language, prompting some to describe it as the rst buzzword-compliant programming language. We submit that to deserve full certiication|and in the process establish itself as the natural choice for developing large-scale distributed applications|Java misses a crucial buzzword: fault-tolerant. We outline some promising research directions for building reliable Java-based applications. 1 Introduction Java may well be the most exciting technology of our time 2], but the excitement never appeared to leave its proponents speechless. Simple, object-oriented, distributed, interpreted, robust, secure, architectural neutral, portable, high-performance, mul-tithreaded and dynamic 5]|these are some of the buzzwords that have been used to characterize Java since its rst introduction. The vision of enterprise computing|a seamless integration of data and communication across thousands of machines to provide better services to citizens and greater opportunities to businesses|seemed to be at hand. Remarkably, Java has substantially fulllled many of the promises behind these buzzwords. Today, Java stands unchallenged in its ability to support true platform-independence and in its integration of security mechanisms. In addition, Java provides adequate support for distribution through Remote Method In-vocation and run-time loading of classes. Performance is also becoming acceptable, thanks to the development of ever more sophisticated Just-in-Time compilers. And yet, we submit that Java will fall short of what is required to realize the vision of enterprise computing until it explicitly addresses a conspicuous buzzword that it has so far overlooked: fault-tolerance. 2 Fault-Tolerance: the Ugly Duckling Building distributed applications forces one to consider the possibility of partial failures. In fact, the kind of wide-area network applications that are likely to be programmed in Java are more vulnerable to partial failures than the relatively constrained applications that are common today. Furthermore, even as languages such as Java make it easier to develop distributed applications and to launch them on the Internet, they do not relieve programmers from the challenge of writing correct distributed algorithms. As distributed applications become commonplace , we envision that fault-tolerance will become a pressing concern for many more application users and developers. That Java makes no explicit provisions for fault-tolerance may be partly due to historical reasons: Java was originally conceived as a language for developing software for consumer electronics operating in an environment much more reliable than the Internet. Also, it probably does not help that fault-tolerance is hardly …