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出典:『Wikipedia』 (2011/05/04 13:18 UTC 版)

英語による解説

引用

The term live distributed object (also abbreviated as live object) refers to a running instance of a distributed multi-party (or peer-to-peer) protocol, viewed from the object-oriented perspective, as an entity that has a distinct identity, may encapsulate internal state and threads of execution, and that exhibits a well-defined externally visible behavior. The key programming language concepts, as applied to live distributed objects, are defined as follows.

• Identity. The identity of a live distributed object is determined by the same factors that differentiate between instances of the same distributed protocol. The object consists of a group of software components physically executing on some set of physical machines and engaged in mutual communication, each executing the distributed protocol code with the same set of essential parameters, such as the name of a multicast group, the identifier of a publish-subscribe topic, the identity of a membership service, etc. Thus, for example, publish-subscribe channels and multicast groups are examples of live distributed objects: for each channel or group, there exists a single instance of a distributed protocol running among all computers sending, forwarding, or receiving the data published in the channel or multicast within the group. In this case, the object's identity is determined by the identifier of the channel or group, qualified with the identity of the distributed system that provides, controls, and manages the given channel or group. In the case of multicast, the identity of the system might be determined, for example, by the address of the membership service (the entity that manages the membership of the multicast group).