异步传输 同步传输 有一个最大得端到端的延时 复杂流 complex stream QoS（quanlity of service) 服务质量 连续帧缺失会影响观看 丢掉不连续的帧，不是很影响观看 Gossip （一个通信协议） epidemic behavior (流行病模型) Anti-entropy Propagation Model （反熵…

分区计算 能分区计算的场景： 淘宝（根据商品分区），游戏（根据服务器分区） 不能分区计算的： QQ, 铁路买票。（关系网络每个点都有联系，不能划分开） Peer-to-peer Architectures From a high-level perspective, the nodes that constitute a peer-to-peer …

Thread Granularity(粒度) of processes as provided by the operating systems on which distributed systems are built is not sufficient. (操作系统给的进程的资源过大，粒度不都细) Multiple threads per p…

分布式系统的特点 Distributed systems should be relatively easy to expand or scale – independent computers is easy to add Distributed systems should normally be continuously available …