Daniel Grosu

Noncooperative load balancing in distributed systems

In this paper, we present a game theoretic framework for obtaining a user-optimal load balancing scheme in heterogeneous distributed systems. We formulate the static load balancing problem in heterogeneous distributed systems as a noncooperative game among users. For the proposed noncooperative load balancing game, we present the structure of the Nash equilibrium. Based on this structure we derive a new distributed load balancing algorithm. Finally, the performance of our noncooperative load balancing scheme is compared with that of other existing schemes. The main advantages of our load balancing scheme are the distributed structure, low complexity and optimality of allocation for each user.

Combinatorial auction-based allocation of virtual machine instances in clouds

The current cloud computing platforms allocate virtual machine instances to their users through fixed-price allocation mechanisms. We argue that combinatorial auction-based allocation mechanisms are especially efficient over the fixed-price mechanisms since the virtual machine instances are assigned to users having the highest valuation. We formulate the problem of virtual machine allocation in clouds as a combinatorial auction problem and propose two mechanisms to solve it. We perform extensive simulation experiments to compare the two proposed combinatorial auction-based mechanisms with the currently used fixed-price allocation mechanism. Our experiments reveal that the combinatorial auction-based mechanisms can significantly improve the allocation efficiency while generating higher revenue for the cloud providers.

Combinatorial auction-based protocols for resource allocation in grids

In this paper, we introduce the combinatorial auction model for resource management in grids. We propose a combinatorial auction-based resource allocation protocol in which a user bids a price value for each of the possible combinations of resources required for its tasks execution. The protocol involves an approximation algorithm for solving the combinatorial auction problem. We implement the new protocol in a simulated environment and study its economic efficiency and its effect on the system performance.

Load balancing in distributed systems: an approach using cooperative games

In this paper we formulate the static load balancing problem in single class job distributed systems as a cooperative game among computers. It is shown that the Nash Bargaining Solution (NBS) provides a Pareto optimal allocation which is also fair to all jobs. We propose a cooperative load balancing game and present the structure of the NBS For this game an algorithm for computing NBS is derived. We show that the fairness index is, always 1 using NBS which means that the allocation is fair to all jobs. Finally, the performance of our cooperative load balancing scheme is compared with that of other existing schemes.

A Combinatorial Auction-Based Mechanism for Dynamic VM Provisioning and Allocation in Clouds

Cloud computing providers provision their resources into different types of virtual machine (VM) instances that are then allocated to the users for specific periods of time. The allocation of VM instances to users is usually determined through fixed-price allocation mechanisms that cannot guarantee an economically efficient allocation and the maximization of cloud providers revenue. A better alternative would be to use combinatorial auction-based resource allocation mechanisms. This argument is supported by the economic theory; when the auction costs are low, as is the case in the context of cloud computing, auctions are especially efficient over the fixed-price markets because products are matched to customers having the highest valuation. The existing combinatorial auction-based VM allocation mechanisms do not take into account the users demand when making provisioning decisions, that is, they assume that the VM instances are statically provisioned. We design an auction-based mechanism for dynamic VM provisioning and allocation that takes into account the user demand, when making provisioning decisions. We prove that our mechanism is truthful (i.e., a user maximizes its utility only by bidding its true valuation for the requested bundle of VMs). We evaluate the proposed mechanism by performing extensive simulation experiments using real workload traces. The experiments show that the proposed mechanism yields higher revenue for the cloud provider and improves the utilization of cloud resources.

A Distributed Algorithm for the Replica Placement Problem

Caching and replication of popular data objects contribute significantly to the reduction of the network bandwidth usage and the overall access time to data. Our focus is to improve the efficiency of object replication within a given distributed replication group. Such a group consists of servers that dedicate certain amount of memory for replicating objects requested by their clients. The content replication problem we are solving is defined as follows: Given the request rates for the objects and the server capacities, find the replica allocation that minimizes the access time over all servers and objects. We design a distributed approximation algorithm that solves this problem and prove that it provides a 2-approximation solution. We also show that the communication and computational complexity of the algorithm is polynomial with respect to the number of servers, the number of objects, and the sum of the capacities of all servers. Finally, we perform simulation experiments to investigate the performance of our algorithm. The experiments show that our algorithm outperforms the best existing distributed algorithm that solves the replica placement problem.

Combinatorial Auction-Based Allocation of Virtual Machine Instances in Clouds

The current cloud computing platforms allocate virtual machine instances to their users through fixed-price allocation mechanisms. We argue that combinatorial auction-based allocation mechanisms are especially efficient over the fixed-price mechanisms since the virtual machine instances are assigned to users having the highest valuation. We formulate the problem of virtual machine allocation in clouds as a combinatorial auction problem and propose two mechanisms to solve it. We perform extensive simulation experiments to compare the two proposed combinatorial auction-based mechanisms with the currently used fixed-price allocation mechanism. Our experiments reveal that the combinatorial auction-based mechanisms can significantly improve the allocation efficiency while generating higher revenue for the cloud providers.

Double auction protocols for resource allocation in grids

In this paper we propose the double auction allocation model for grids, and three double auction protocols for resource allocation: Preston-McAfee Double Auction Protocol (PMDA), threshold price double auction protocol (TPDA) and continuous double auction protocol (CDA). We study these protocols in terms of economic efficiency and system performance. The results show that CDA protocol is better from both resources and users perspective providing high resource utilization.

A class of loop self-scheduling for heterogeneous clusters

Distributed Computing Systems are a viable and less expensive alternative to parallel computers. However, a serious difficulty in concurrent programming of a distributed system is how to deal with scheduling and load balancing of such a system which may consist of heterogeneous computers. Distributed scheduling schemes suitable for parallel loops with independent iterations on heterogeneous computer clusters have been designed in the past. In this work we consider a class of Self-Scheduling schemes for parallel loops with independent iterations which have been applied to multiprocessor systems. We extend this type of schemes to heterogeneous distributed systems. We present tests that the distributed versions of these schemes maintain load balanced execution on heterogeneous systems.

Energy-Aware Scheduling of MapReduce Jobs for Big Data Applications

The majority of large-scale data intensive applications executed by data centers are based on MapReduce or its open-source implementation, Hadoop. Such applications are executed on large clusters requiring large amounts of energy, making the energy costs a considerable fraction of the data centers overall costs. Therefore minimizing the energy consumption when executing each MapReduce job is a critical concern for data centers. In this paper, we propose a framework for improving the energy efficiency of MapReduce applications, while satisfying the service level agreement (SLA). We first model the problem of energy-aware scheduling of a single MapReduce job as an Integer Program. We then propose two heuristic algorithms, called energy-aware MapReduce scheduling algorithms (EMRSA-I and EMRSA-II), that find the assignments of map and reduce tasks to the machine slots in orderto minimize the energy consumed when executing the application. We perform extensive experiments on a Hadoop cluster to determine the energy consumption and execution time for several workloads from the HiBench benchmark suite including TeraSort, PageRank, and K-means clustering, and then use this data in an extensive simulation study to analyze the performance of the proposed algorithms. The results show that EMRSA-I and EMRSA-II are able to find near optimal job schedules consuming approximately 40 percent less energy on average than the schedules obtained by a common practice scheduler that minimizes the makespan.