Gossiping is a communication mechanism, used for fast information dissemination in a network, where each node of the network randomly shares its information with the neighboring nodes. To characterize the notion of fastness in the context of gossip networks, age of information (AoI) is used as a timeliness metric. In this article, we summarize the recent works related to timely gossiping in a network. We start with the introduction of randomized gossip algorithms as an epidemic algorithm for database maintenance, and how the gossiping literature was later developed in the context of rumor spreading, message passing and distributed mean estimation. Then, we motivate the need for timely gossiping in applications such as source tracking and decentralized learning. We evaluate timeliness scaling of gossiping in various network topologies, such as, fully connected, ring, grid, generalized ring, hierarchical, and sparse asymmetric networks. We discuss age-aware gossiping and the higher order moments of the age process. We also consider different variations of gossiping in networks, such as, file slicing and network coding, reliable and unreliable sources, information mutation, different adversarial actions in gossiping, and energy harvesting sensors. Finally, we conclude this article with a few open problems and future directions in timely gossiping.

翻译：八卦机制是一种用于在网络中快速传播信息的通信机制，网络中每个节点随机与相邻节点共享自身信息。为刻画八卦网络中“快速”这一概念，信息时效（AoI）被用作时限性度量指标。本文综述了网络中及时八卦的最新研究成果。我们首先介绍随机八卦算法作为数据库维护的流行病算法，以及八卦文献如何在后来的谣言传播、消息传递和分布式均值估计中得到发展。随后，我们论证了在源跟踪和去中心化学习等应用中需要及时八卦的动机。我们评估了各种网络拓扑（如全连接、环状、网格、广义环状、分层及稀疏非对称网络）中八卦的时限性扩展特性。本文讨论了年龄感知型八卦以及年龄过程的高阶矩，还考虑了网络八卦的不同变体，包括文件切片与网络编码、可靠与不可靠源、信息变异、八卦中的不同对抗行为以及能量采集传感器。最后，本文以及时八卦领域的若干开放问题与未来方向作为总结。