A pipelined SinglePhase Paxos Extension without lease Variety of singlephase consensus protocols based on Paxos have made significant progress in low latency and high performance. However, these improvements are either limited to specific favorable conditions, such as most commands rarely dependencies on each other, or weaken system availability with bigger fast writes quorums requirement or designated leader. In this paper, Decree Promise Paxos (DP Paxos) is proposed and implemented. DP Paxos provides singlephase fast writes without commands dependency restriction by leveraging a no lease and dynamic Decree Promised leader. The singlephase fast writes only require quorums composed of a majority of legislator nodes, these quorums are the minimum requirement to solve consensus. In most leader and lease system, followers redirect all requests to the leader, leader failure causes the system stuck till the lease expired and new leader is elected. DP Paxos solved the stuck problem by allowing followers proposal commands via twophase Paxos instances when it receives client requests. Followers and leader may compete to proposal different commands. Normally, too many collisions of competing proposals will result in expensive coordinate cost and poor performance. In our scenario, 3node cluster provides remarkable available improvement and acceptable cost for largescale deployment. In DP Paxos, we design a xe2x80x99reservexe2x80x99 and xe2x80x99oddeven gearxe2x80x99 mechanism to reduce collisions, it is very efficient for coordinating two nodes competing proposals in 3nodes cluster. Generally, each proposer node propose 50 percent of client requests will cause massive collision, but after the DP Paxos optimization, these collisions are decreased to unbelievable rarely. Moreover, a busiest follower proposer substitutes the previous leader in very simple and cheap way, just attaching few bytes of election info within a normal command. The busiest node play the leader role, ensure more than half of client requests are reach consensus in singlephase. Decree Promise Paxos is not only a theoretical algorithm, but also implemented and applied in some online games data cache service of Tencent, where it processes 3.6 billion writes per day.

Hermes: a Fast, FaultTolerant and Linearizable Replication Protocol. Todayu0027s datacenter applications are underpinned by datastores that are responsible for providing availability, consistency, and performance. For high availability in the presence of failures, these datastores replicate data across several nodes. This is accomplished with the help of a reliable replication protocol that is responsible for maintaining the replicas stronglyconsistent even when faults occur. Strong consistency is preferred to weaker consistency models that cannot guarantee an intuitive behavior for the clients. Furthermore, to accommodate high demand at realtime latencies, datastores must deliver high throughput and low latency.  :87,work introduces Hermes, a broadcastbased reliable replication protocol for inmemory datastores that provides both high throughput and low latency by enabling local reads and fullyconcurrent fast writes at all replicas. Hermes couples logical timestamps with cachecoherenceinspired invalidations to guarantee linearizability, avoid write serialization at a centralized ordering point, resolve write conflicts locally at each replica (hence ensuring that writes never abort) and provide faulttolerance via replayable writes. Our implementation of Hermes over an RDMAenabled reliable datastore with five replicas shows that Hermes consistently achieves higher throughput than stateoftheart RDMAbased reliable protocols (ZAB and CRAQ) across all write ratios while also significantly reducing tail latency. At 5% writes, the tail latency of Hermes is 3.6X lower than that of CRAQ and ZAB.