It has been a long-standing open problem to determine the exact randomized competitiveness of the 2-server problem, that is, the minimum competitiveness of any randomized online algorithm for the 2-server problem. For deterministic algorithms the best competitive ratio that can be obtained is 2 and no randomized algorithm is known that improves this ratio for general spaces. For the line, Barta...

We focus on how to securely outsource computation task to the cloud and propose a secure outsourcing multiparty computation protocol on lattice-based encrypted data in two-cloud-servers scenario. Our main idea is to transform the outsourced data respectively encrypted by different users' public keys to the ones that are encrypted by the same two private keys of the two assisted servers so that ...

Java has, in recent years, become fairly popular as a platform for commercial servers. However, the behavior of Java server applications has not been studied extensively. We characterize two multithreaded Java server benchmarks, SPECjbb2000 and VolanoMark 2.1.2, on two IBM PowerPC architectures, the RS64-III and the POWER3-II, and compare them to more traditional workloads as represented by sel...

We consider the class of balancing algorithms for two servers. Such algorithms have appeared in a number of the early papers on this problem; they are so named because they seek to \balance" the distance traveled evenly among the servers. In this paper, we show a universal lower bound on the competitive ratio of any balancing algorithm for two servers. The lower bound is equal to (5 + p 7)=2 (3...

In this paper we study two echelon multi-server tandom queueing systems where customers arrive according to a poisson process with two different rates. The service rates at both echelons are independent of each other. The service times of customers is assumed to be completed in two stages. The service times at each stage are exponentially distributed. At the first stage, the customers may balk ...

Consider a tandem queueing network with an infinite supply of jobs in front of the first station, infinite room for completed jobs after the last station, finite buffers between stations, and a number of flexible servers who are subject to failures. We study the dynamic assignment of servers to stations with the goal of maximizing the long-run average throughput. Our main conclusion is that the...

Swarm is a storage system that provides scalable, reliable, and cost-effective data storage. Swarm is based on storage servers, rather than file servers; the storage servers are optimized for cost-performance and aggregated to provide high-performance data access. Swarm uses a striped log abstraction to store data on the storage servers. This abstraction simplifies storage allocation, improves ...

We study an M/M/2 queueing system with two heterogeneous servers under a variant vacation policy, where the two servers may take together at most J vacations when the system is empty. A quasi-birth-and-death process is formulated to analyze the system. We obtain the explicit expressions of the stationary distribution of the system size and the mean system size. We also show that the number of v...