Title
Characterizing and Adapting the Consistency-Latency Tradeoff in Distributed Key-value Stores
Abstract
The CAP theorem is a fundamental result that applies to distributed storage systems. In this article, we first present and prove two CAP-like impossibility theorems. To state these theorems, we present probabilistic models to characterize the three important elements of the CAP theorem: consistency (C), availability or latency (A), and partition tolerance (P). The theorems show the un-achievable envelope, that is, which combinations of the parameters of the three models make them impossible to achieve together. Next, we present the design of a class of systems called Probabilistic CAP (PCAP) that perform close to the envelope described by our theorems. In addition, these systems allow applications running on a single data center to specify either a latency Service Level Agreement (SLA) or a consistency SLA. The PCAP systems automatically adapt, in real time and under changing network conditions, to meet the SLA while optimizing the other C/A metric. We incorporate PCAP into two popular key-value stores: Apache Cassandra and Riak. Our experiments with these two deployments, under realistic workloads, reveal that the PCAP systems satisfactorily meets SLAs and perform close to the achievable envelope. We also extend PCAP from a single data center to multiple geo-distributed data centers.
Year
DOI
Venue
2015
10.1145/2997654
ACM Transactions on Autonomous and Adaptive Systems (TAAS)
Keywords
Field
DocType
Consistency,adaptivity,distributed storage
Latency (engineering),CAP theorem,Computer science,Service-level agreement,Distributed data store,Impossibility,Real-time computing,Probabilistic logic,Partition (number theory),Data center,Distributed computing
Journal
Volume
Issue
ISSN
11
4
1556-4665
Citations 
PageRank 
References 
11
0.68
46
Authors
5
Name
Order
Citations
PageRank
Muntasir Raihan Rahman145521.21
Lewis Tseng217723.92
Nguyen Son34211.72
Indranil Gupta41837143.92
Nitin H. Vaidya586591166.40