etcd 3.0标志着etcd 3.0的第一个稳定版本的API和数据模型发布，升级很简单，因为同样的etcd2 JSON的端点和内部的集群协议在etcd3仍然提供。尽管如此，但etcd3是基于etcd2用户和实践经验的反馈对API进行大规模的重新设计的。值得关注的更新内容有效率，可靠性和并发控制等一些显著的改进。 更新日志： Improved latency and throughput Less protocol overhead via gRPC API layer Better disk utilization in write ahead log New storage backend: lower memory overhead per key Automatic TLS configuration Some highlights of the new stable etcd3 API: Flat binary keyspace: no key-value hierarchy / directories Support key get and watch by prefix Support key get and watch by interval Multiversion keyspace: access historical revisions of keys Transactions: combine multiple requests into one operation Leases: a single TTL for sets of keys Maintenance/Alarm: protect etcd from accidental overutilization with storage quotas Some highlights of new etcdctl: Mirror: mirror etcd to another data center Lock: mutex on top of etcd Elect: leader election Snapshot: stores point-in-time state of etcd backend Endpoint: health checking Experimental Features/APIs: v3 Auth API etcd gateway subcommand 下载地址：https://github.com/coreos/etcd/releases/tag/v3.0.0 etcd 3.0 发布，高可用 Key/Value 存储系统下载地址
