jberets@bbn.com (Jim Berets) (03/01/88)
Cronus is a distributed operating system currently under development at BBN Laboratories. Its major goal is to provide a coherent and integrated environment in which distributed applications can easily be built. Significant Cronus features include: + operation in a heterogeneous environment, including underlying hardware architectures, programming languages and environments, and network technology; + interoperability and coexistance with existing software bases, non-distributed operating systems (such as UNIX, VMS, and Genera), and applications; + a complete environment in which to develop integrated distributed applications; + delivery of the application development environment to developers in a way that is easy to use. Cronus has been designed as a base for the development of large-scale distributed heterogeneous applications. Although internally the system is object-oriented, this aspect of Cronus is largely hidden from application developers. Most of the details of implementing distributed applications are provided by a combination of code automatically generated from an interface specification (including an RPC interface for clients), library routines, and system components. The underlying Cronus object model is the basis for interprocess communication; object location, migration, and replication; high-level resource management; and access control. It is also the primary means for system decomposition and data abstraction. System and application resources are instances of object types, and are under the control of one or more managers for that type scattered throughout the network. Clients affect objects by invoking operations (determined by the type and its parents in a type hierarchy) upon them. A number of system managers provide commonly used functions to any application: a symbolic naming service, an authentication facility, a filesystem, and configuration control. Cronus is currently running at six sites. The most recent release (1.2, written in C) includes full support for VAX systems running VMS, Ultrix, and BSD UNIX; Sun Microsystems systems running the Sun O/S; and Masscomp systems running RTU. Soon to be available are implementations for the Symbolics (in Common Lisp) and IBM PC-compatibles. Several applications have been written for Cronus, including single- and multi-site command and control simulations, software management tools, and office automation applications. For further information contact: James C. Berets BBN Laboratories 10 Moulton Street Cambridge, MA 02238 (617) 873-2593 jberets@bbn.com Selected references: %A Michael A. Dean %A Richard E. Mackey, Jr. %T Protocol Driven User Interfaces in an Object-Oriented Distributed System %I to appear in the Proceedings of the Third Annual User-System Interface Conference (USICON '88) %D February 1988 %A Michael A. Dean %A Richard M. Sands %A Richard E. Schantz %T Canonical Data Representation in the Cronus Distributed Operating System %I 1987 IEEE Communications and Computer Societies INFOCOM Conference %P 814-819 %D March 1987 %A R. Schantz %A R. Thomas %A G. Bono %T The Architecture of the Cronus Distributed Operating System %B Sixth International Conference on Distributed Computing Systems %I IEEE Computer Society %P 250-259 %D May 1986 %A R. Gurwitz %A M. Dean %A R. Schantz %T Programming Support in the Cronus Distributed Operating System %B Sixth International Conference on Distributed Computing Systems %I IEEE Computer Society %P 486-493 %D May 1986 %A James C. Berets %A Ronald A. Mucci %A Richard E. Schantz %T Cronus: A Testbed for Developing Distributed Systems %I 1985 IEEE Military Communications Conference %P 409-417 %D October 1985