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Colloquium Details

Optimizing Cloud Resource Allocation and Reconfiguration

Author:Lei Jiao Nokia Bell Labs, Ireland
Date:June 07, 2016
Time:15:30
Location:220 Deschutes

Abstract

Resource allocation and reconfiguration is fundamental in cloud computing, and becomes more challenging as cloud services and architectures continue to evolve wit​h ​complexities. In the service aspect, online social networks are popular, and allocating storage for users​' data over multiple clouds needs to address the interconnection of users,​ ​the master-slave data replication, the conflicting requirements of different objectives, as well as the diversity of multi-cloud data access policies. In the architecture aspect, the​ ​emerging edge-core tiered structure of distributed clouds complicates the allocation of resources such as virtual machines and servers, due to the reconfiguration cost associated​ ​to changing resource allocation decisions over time, the often unpredictable service demands and resource prices, as well as the heterogeneity of resources.

In this talk, I will introduce our work on exploiting optimization to solve these two problems​,​ while addressing all the aforementioned challenges. The first problem is a large-scale​ ​combinatorial optimization problem regarding social network data placement over clouds, potentially with multiple system objectives such as carbon footprint, latency, and​ ​inter-​cloud traffic. We propose to decompose it into two sub-problems of placing master data replicas and slave data replicas respectively, where we leverage the graph cuts technique​ ​to solve the master placement problem, use a greedy method to place the slaves, and solve the two sub-problems alternately in multiple rounds. The second problem is an online​ ​optimization problem regarding cloud and network resource allocation over time ​to process dynamic workloads ​in a tiered infrastructure, where a resource allocation decision needs to be​ ​made on the fly without knowing the entire inputs over the time horizon. With​ no​ knowledge of future inputs, we leverage the regularization technique to design an online algorithm​ ​that decomposes the original problem by constructing a series of sub-problems solvable at each corresponding time slot, with provable worst-case​ ​performance​ ​guarantee​s​. Experiments with real-world data traces confirm that our approaches have substantial advantages over the state of the arts.

Biography

Lei​ Jiao is a post-doctoral ​​researcher​ at Nokia Bell Labs in Dublin, Ireland​. ​​His research interests are broadly in theories and algorithms (e.g.,​ ​optimization, control, game​ ​theory), with a focus on modeling, analyzing, and solving real-world problems in distributed and networked systems.​ ​His research appeared in conferences such as IEEE INFOCOM, ICNP, IPDPS, and in journals such as IEEE/ACM Transactions on Networking. He was also a recipient of the Best Paper Award in IEEE LANMAN 2013. He​ received ​the​ Ph.D.​ ​degree in computer science from University of ​​Gö​ttingen in G​ö​ttingen, Germany in 2014. ​Prior to ​his Ph.D. study, ​he​ was a ​​researcher​ ​at IBM Research in Beijing, China.