This paper introduces several budget-aware algorithms to deploy scientific workflows on laaS Cloud platforms, where users can request Virtual Machines (VMs) of different types, each with specific cost and speed parame...
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ISBN:
(纸本)9781538655559
This paper introduces several budget-aware algorithms to deploy scientific workflows on laaS Cloud platforms, where users can request Virtual Machines (VMs) of different types, each with specific cost and speed parameters. We use a realistic application/platform model with stochastic task weights, and VMs communicating through a datacenter. We extend two well-known algorithms, MIN-MIN and HEFT, and make scheduling decisions based upon machine availability and available budget. During the mapping process, the budget-aware algorithms make conservative assumptions to avoid exceeding the initial budget;we further improve our results with refined versions that aim at re-scheduling some tasks onto faster VMs, thereby spending any budget fraction leftover by the first allocation. These relined variants are much more time-consuming than the former algorithms, so there is a trade-off to find in terms of scalability. We report an extensive set of simulations with workflows from the Pegasus benchmark suite. Most of the time our budget-aware algorithms succeed in achieving efficient makespans while enforcing the given budget, despite (I) the uncertainty in task weights and (ii) the heterogeneity of VMs in both cost and speed values.
Traffic rerouting is a technique used to optimize traffic flow and reduce congestion by redirecting vehicles to alternate routes. The work done in this research focuses on a specific case scenario covering a 25 k...
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As modern VLSI technology is scaling to the deep sub-micron domain, embedded systems face a power-efficiency problem, i.e., static power consumption caused by the leakage current. This paper explores how to use dynami...
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ISBN:
(纸本)9780769545028
As modern VLSI technology is scaling to the deep sub-micron domain, embedded systems face a power-efficiency problem, i.e., static power consumption caused by the leakage current. This paper explores how to use dynamic power management to reduce static power consumption while guaranteeing hard real-time properties. To tackle event arrivals with non-deterministic patterns, the arrival curve model is adopted to describe event arrivals in the interval domain. To reduce runtime overhead, periodic power management is investigated, which turns on and off a system with a fixed period. To reduce the timing complexity of computing such a periodic scheme, two algorithms, which are based on a linear-segmented representation of the arrival curve model, are proposed to trade the complexity with accuracy for energy reduction. We also present simulation results to demonstrate the effectiveness of our algorithms.
scheduling algorithms are of utmost importance in WiMAX for efficient use of radio resources. A scheduling algorithm should take into account the WiMAX QoS classes and service requirements. It should also provide high...
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ISBN:
(纸本)9781424431205
scheduling algorithms are of utmost importance in WiMAX for efficient use of radio resources. A scheduling algorithm should take into account the WiMAX QoS classes and service requirements. It should also provide high throughput. In this paper, we propose a review of scheduling algorithms proposed for WiMAX. We focus on the real-time Polling Service (rtPS) QoS class. NS-2 simulations show interesting results. We highlight a problem that may exist with the WiMAX rtPS QoS class and we provide solutions for it. Simulation results concerning proposed WiMAX schedulers are discussed. We propose an enhancement of the maximum Signal-to-Interference Ratio (mSIR) scheduler, called modified maximum Signal-to-Interference Ratio (mmSIR). We show through extensive simulations that this enhancement provides better mean sojourn time in addition to an improvement in throughput.
The concept of the Internet of Everything (IoE) is an area of great interest, with a lot of attention. The fact that it is used in almost all areas makes this concept progress much faster. The devices used in the envi...
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ISBN:
(纸本)9781728112442
The concept of the Internet of Everything (IoE) is an area of great interest, with a lot of attention. The fact that it is used in almost all areas makes this concept progress much faster. The devices used in the environments of this concept are required to be minimal in terms of hardware as well as their energy consumption. Although there are different ways of minimizing energy consumption in these devices, one of the most promising protocols that provide mentioned demands is the IEEE 802.15.4e Time Slotted Channel Hopping (TSCH) Medium Access Control (MAC) protocol. This protocol runs on 802.15.4 radio and requires a communication schedule for MAC. How and when these schedules, updates and maintenance will take place are not covered by this protocol. Several solutions are available in the literature to solve these problems. Distributed divergecast Aloha based scheduling and DIVA scheduling algorithms are two of these solutions. Both algorithms make their scheduling according to certain probability calculations. Changing the values of these probability calculations is a novel research with evaluation results in this paper. The aim of this study is to examine the effect of the change in the related probability variables on the performance and try to find the best possible values. It has been observed that the changes in these calculation values have an effect on network converge time.
In this paper we have proposed efficient stream scheduling algorithms for multimedia storage servers that are providers of variable bit rate media streams. We have developed three types of stream scheduling algorithms...
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ISBN:
(纸本)0818686510
In this paper we have proposed efficient stream scheduling algorithms for multimedia storage servers that are providers of variable bit rate media streams. We have developed three types of stream scheduling algorithms: In-Order scheduling Algorithm (IOSA), Out-of-Order scheduling Algorithm (OOSA), and Dynamic Merge scheduling Algorithm (DMSA). In the IOSA scheme, media blocks must be transmitted according to their natural order. In the OOSA scheme, in-order transmission is not mandated and thus results in an out-of-order transmission. In the DMSA scheme, the requests that are possible to be merged are merged together at first. Then the OOSA scheduling scheme is used for the merged requests. The performance evaluations done through simulations show that the maximum bandwidth requirement, the fetch ahead distance, and the coefficient of variation for the band-width requirement are improved by using the IOSA, OOSA, and DMSA algorithms.
In this paper, we deal with the regularity of status updates in a monitoring system. Specifically, we consider a system consisting of independent energy harvesting nodes with adaptive modulation capabilities that tran...
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ISBN:
(纸本)9781665486156
In this paper, we deal with the regularity of status updates in a monitoring system. Specifically, we consider a system consisting of independent energy harvesting nodes with adaptive modulation capabilities that transmit status updates to a non energy harvesting sink over a fading channel. Due to the randomness of the energy arrival and the channel time variations, a node may have difficulties maintaining regular status updates. Hence, the objective of this work is to design scheduling algorithms that minimize the number of violations of inter-delivery time over a finite time horizon. An inter-delivery violation event occurs when the time duration between two consecutive status updates exceeds a given time limit. We focus on online modulation and power adaptation policies where the transmitting sensor node adjusts the M-ary modulation level and transmission power based on both the channel state and the battery level. Specifically, we propose both deterministic and randomized algorithms to efficiently solve the considered scheduling problem for the one-node system. Deterministic solutions were extended to the multi-node system. The numerical results show that the proposed algorithms realize significant gain in terms of violations events compared to the benchmark fixed modulation solutions.
We propose distributed scheduling algorithms that guarantee a constant fraction of the maximum throughput for typical wireless topologies, and have O(1) delay and complexity in the network size. Our algorithms resolve...
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ISBN:
(纸本)9783903176003
We propose distributed scheduling algorithms that guarantee a constant fraction of the maximum throughput for typical wireless topologies, and have O(1) delay and complexity in the network size. Our algorithms resolve collisions among pairs of conflicting nodes by assigning a master-slave hierarchy. When the master-slave hierarchy is chosen randomly, our algorithm matches the throughput performance of the maximal scheduling policies, with a complexity and delay that do not scale with network size. When the master-slave hierarchy is chosen based on the network topology, the throughput performance of our algorithm is characterized by a parameter of the conflict graph called the master-interference degree. For commonly used conflict graph topologies, our results lead to the best known throughput guarantees among the algorithms that have O(1) delay and complexity. Numerical results indicate that our algorithms outperform the existing O(1) complexity algorithms like Q-CSMA.
The input-queued switch architecture is widely used in Internet routers, due to its ability to run at very high line speeds. A central problem in designing an input-queued switch is choosing the scheduling algorithm, ...
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ISBN:
(纸本)9781424402212
The input-queued switch architecture is widely used in Internet routers, due to its ability to run at very high line speeds. A central problem in designing an input-queued switch is choosing the scheduling algorithm, i.e. deciding which packets to transfer from ingress ports to egress ports in a given timeslot. Important metrics for evaluating a scheduling algorithm are its throughput and average delay. The well-studied 'Maximum-Weight' algorithm has been proved to have maximal throughput [11;later work [2]-[4] found a wider class of algorithms which also have maximal throughput. The delay performance of these algorithms is less well understood. In this paper, we present a new technique for analysing scheduling algorithms which can explain their delay performance. In particular, we are able to explain the empirical observations in [2] about the average delay in a parameterized class of algorithms akin to Maximum-Weight. We also propose an optimal scheduling algorithm. Our technique is based on critically-balanced fluid model equations.
In this paper, we are trying to find a algorithm for scheduling DAG (Directed Acyclic Graph) tasks in heterogeneous embedded systems to minimize energy consumption while meeting the reliability requirement. Like many ...
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ISBN:
(纸本)9781665435741
In this paper, we are trying to find a algorithm for scheduling DAG (Directed Acyclic Graph) tasks in heterogeneous embedded systems to minimize energy consumption while meeting the reliability requirement. Like many traditional algorithms, we divide the task scheduling algorithm into two phases, the task priority calculation phase and the task allocation phase. In the task priority calculation phase, we proposes a priority calculation algorithm IOD based on the difference in task's input and output data. In the task allocation stage, we proposes a task allocation algorithm based on fault-tolerant technology of task replication and DVFS technology. Combining the two phase, we get three scheduling algorithms, IODS, IODQ and IODR. In the experimental part, we compare the performance of the algorithm proposed in this paper with existing research algorithms (EFSRG algorithm and HRRM algorithm). The analysis of experimental results shows that the IODS algorithm is a better choice.
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