In this paper we propose a new multi-criteria class-based job scheduler able to dynamically schedule a stream of batch jobs on large-scale computing farms. It is driven by several configuration parameters allowing the scheduler customization with respect to the goals of an installation. The proposed scheduling policies allow to maximize the resource usage and to guarantee the applications QoS r...

Effective scheduling strategies to improve response times, throughput, and utilization are an important consideration in large supercomputing environments. Such machines have traditionally used space-sharing strategies to accommodate multiple jobs at the same time. This approach, however, can result in low system utilization and large job wait times. This paper discusses three techniques that c...

In large Grids, like the National Grid Service (NGS), or large distributed architecture different scheduling entities are involved. Despite a global scheduling approach would archive higher performance and could increment the utilization of global system in these scenarios usually independent schedulers carry out its own scheduling decisions. In this paper we present how a coordinated schedulin...

Although traditional scheduling policies for high-end parallel systems focus on minimizing average job wait time while maximizing system utilization, actual supercomputer workload traces confirm the existence of significant periods of time of low utilization. Previous work has shown that, in the context of backfilling schedulers, portions of such high-end systems can be selectively powered down...

Distributed memory parallel systems such as the IBM SP2 execute jobs using variable partitioning. Scheduling jobs in FCFS order leads to severe fragmentation and utilization loss, which lead to the development of backfilling scheudlers such as EASY. This paper presents a backfilling scheduler that improves EAST in two ways: It supports both user selected and administrative priorities, and guara...

We have investigated oxygen adsorption on Cu(410) by high-resolution electron energy loss spectroscopy, dosing O2 with a supersonic molecular beam at different surface temperatures and for different angles of incidence and beam energies or by backfilling. In the investigated crystal temperature range (127 < T < 570 K), adsorption is always dissociative. Depending on T, impact energy, and angle ...

We focus on non-FCFS job scheduling policies for parallel systems that allow jobs to backfill, i.e., to move ahead in the queue, given that they do not delay certain previously submitted jobs. Consistent with commercial schedulers that maintain multiple queues where jobs are assigned according to the user-estimated duration, we propose a self-adapting backfilling policy that maintains multiple ...

Buffered coscheduling is a new methodology that can substantially increase resource utilization, improve response time, and simplify the development of the run-time support in a parallel machine. In this paper, we provide an in-depth analysis of three important aspects of the proposed methodology: the impact of the communication pattern and type of synchronization, the impact of memory constrai...

Aims of this work were to examine lateral canals in extracted teeth, to propose a new technique to produce artificial lateral canals, and to compare two obturation techniques. Cleared roots were examined to record measure and shape of lateral canals. Artificial lateral canals were prepared on human demineralized teeth before final clearing. Specimens were divided in two groups: canals of group ...

This study seeks to address the problems of major geo-environmental hazards caused by high-intensive coal mining in China’s western eco-environment frangible area including strong mining pressure, surface subsidence, soil and water loss, and land desertification. Using the high-intensive mining at the Xiao-jihan Coal Mine, this paper investigates the compaction characteristics of aeolian sand-b...