human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "ready for rain a view from spec research on the future of cloud metrics"
  Abstract: In the past decade, cloud computing has emerged from a pursuit for a service-driven information and communication technology (ICT), into a signifcant fraction of the ICT market. Responding to the growth of the market, many alternative cloud services and their underlying systems are currently vying for the attention of cloud users and providers. Thus, benchmarking them is needed, to enable cloud users to make an informed choice, and to enable system DevOps to tune, design, and evaluate their systems. This requires focusing on old and new system properties, possibly leading to the re-design of classic benchmarking metrics, such as expressing performance as throughput and latency (response time), and the design of new, cloud-specififc metrics. Addressing this requirement, in this work we focus on four system properties: (i) elasticity of the cloud service, to accommodate large variations in the amount of service requested, (ii) performance isolation between the tenants of shared cloud systems, (iii) availability of cloud services and systems, and the (iv) operational risk of running a production system in a cloud environment.Focusing on key metrics, for each of these properties we review the state-of-the-art, then select or propose new metrics together with measurement approaches. We see the presented metrics as a foundation towards upcoming, industry-standard, cloud benchmarks. #R##N#Keywords: Cloud Computing; Metrics; Measurement; Benchmarking; Elasticity; Isolation; Performance; Service Level Objective; Availability; Operational Risk.

Connected through hyperedge HE-1 (induced by source paper "massivizing computer systems a vision to understand design and engineer computer ecosystems through and beyond modern distributed systems"):
  with members:
    - "a tree a bounded approximate index structure"
    - "weld rethinking the interface between data intensive applications"
    - "self awareness of cloud applications"
    - "what next a dozen information technology research goals"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.DC(Distributed, Parallel, and Cluster Computing)