论文标题
零消息，信息和协调
Null Messages, Information and Coordination
论文作者
论文摘要
本文调查了无效消息在具有和没有故障的同步系统中所扮演的角色，并为信息传输和协调的协议结构提供了必要和充分的条件。我们首先引入一个新的，更完善的空消息定义。提供了允许这些无效消息的消息链的概括，并且证明是必要的，足以在可靠的系统中的信息传输。应对崩溃故障需要更丰富的结构，因为未收到消息可能是发件人故障的结果。我们介绍了一种称为{\ em弹性消息块}的通信模式，该模式比Goren和Moses的{\ em Silent Choirs}对协议施加更严格的条件。这些块被证明是在容易发生系统中的信息传输所必需的。此外，在一些感兴趣的情况下，它们不足以使沉默的合唱团没有。最后，证明有弹性消息块的特定组合被证明是必要的，足以解决有序的响应协调问题。
This paper investigates the role that null messages play in synchronous systems with and without failures, and provides necessary and sufficient conditions on the structure of protocols for information transfer and coordination there. We start by introducing a new and more refined definition of null messages. A generalization of message chains that allow these null messages is provided, and is shown to be necessary and sufficient for information transfer in reliable systems. Coping with crash failures requires a much richer structure, since not receiving a message may be the result of the sender's failure. We introduce a class of communication patterns called {\em resilient message blocks}, which impose a stricter condition on protocols than the {\em silent choirs} of Goren and Moses (2020). Such blocks are shown to be necessary for information transfer in crash-prone systems. Moreover, they are sufficient in several cases of interest, in which silent choirs are not. Finally, a particular combination of resilient message blocks is shown to be necessary and sufficient for solving the Ordered Response coordination problem.
