Architecture and Operation Invocation in the Clouds Kernel

Many distributed opcraLing systems have been developed in recent years based on the acLion/object paradigm. The Clouds mullicamputee system provides a faull-tolemnt distributed compuling environment buill from passive data objccts,fault-aromic lransactions, processes, and a global kemel inlerface implemented on LOp of unreliable hardware. Key to the successful functioning of Clouds is its simple architecture consisling of passive, abslI'act data objccts and me uniform operation invocation m~hanism. This architecture allows plain processes or nested lransactions La access user and SYSLeffi data in a lransparem, uniform manner, whether those objects are local to the eurrent machine or on some remoLe processor. The same basic interface used to make opcl'lluon invocation requests on objects can be used to spawn processes and actions, and LO gain access to resLriCLed kernel services. This paper presents an abbreviated description of the Clouds architecture and its relation to the operation of the invocation mechanism, including remote invocation, perobjcct access control, and location independent invocation. Some conclusions derived from the first prototype arc also presented.