Effective Resource Allocation in Parallel Quantum-Chemical Calculations

Key factors affecting the parallel efficiency of archetypical quantum-chemical calculations are discussed. Effective load balancing schemes are proposed. Introduction of the memory affinity to the balancing process is shown to result in super-linear scaling

Efficient Resource Matching in Heterogeneous Grid Using Resource Vector

In this paper, a method for efficient scheduling to obtain optimum job throughput in a distributed campus grid environment is presented; Traditional job schedulers determine job scheduling using user and job resource attributes. User attributes are related to current usage, historical usage, user priority and project access. Job resource attributes mainly comprise of soft requirements (compilers, libraries) and hard requirements like memory, storage and interconnect. A job scheduler dispatches jobs to a resource if a job's hard and soft requirements are met by a resource. In current scenario during execution of a job, if a resource becomes unavailable, schedulers are presented with limited options, namely re-queuing job or migrating job to a different resource. Both options are expensive in terms of data and compute time. These situations can be avoided, if the often ignored factor, availability time of a resource in a grid environment is considered. We propose resource rank approach, in which jobs are dispatched to a resource which has the highest rank among all resources that match the job's requirement. The results show that our approach can increase throughput of many serial / monolithic jobs.Comment: 10 page

Hybrydowe zrównoleglenie podstawowych algorytmów kwantowo-chemicznych

Przedstawiono hybrydowo zrównoleglone warianty metod Hartreego-Focka, Kohna-Shama i rachunku zaburzeń Møllera-Plesseta drugiego rzędu. Porównano ich wydajność względem implementacji szeregowej i implementacji zrównoleglonej za pomocą mechanizmu przekazywania komunikatów (MPI). Pokazano, ze hybrydowe zrównoleglenie zapewnia zwiększona wydajność we wszystkich analizowanych przypadkach, przy czym wielkość uzyskanego przyspieszenia silnie zależy od cech danego algorytmu.Hybrid-parallel variants of Hartree-Fock, Kohn-Sham and Møller-Plesset second-level perturbation theory are described. Their efficiency with respect to the serial and MPI-based parallel implementations are measured and briefly analyzed. It is shown that while hybrid parallelization provide increased efficiency in all cases, the magnitude of the effect strongly depends on the features of the particular algorithm

Clustering Algorithms for Scale-free Networks and Applications to Cloud Resource Management

In this paper we introduce algorithms for the construction of scale-free networks and for clustering around the nerve centers, nodes with a high connectivity in a scale-free networks. We argue that such overlay networks could support self-organization in a complex system like a cloud computing infrastructure and allow the implementation of optimal resource management policies.Comment: 14 pages, 8 Figurs, Journa

Lattice QCD Thermodynamics on the Grid

We describe how we have used simultaneously ${\cal O}(10^3)$ nodes of the EGEE Grid, accumulating ca. 300 CPU-years in 2-3 months, to determine an important property of Quantum Chromodynamics. We explain how Grid resources were exploited efficiently and with ease, using user-level overlay based on Ganga and DIANE tools above standard Grid software stack. Application-specific scheduling and resource selection based on simple but powerful heuristics allowed to improve efficiency of the processing to obtain desired scientific results by a specified deadline. This is also a demonstration of combined use of supercomputers, to calculate the initial state of the QCD system, and Grids, to perform the subsequent massively distributed simulations. The QCD simulation was performed on a $16^3\times 4$ lattice. Keeping the strange quark mass at its physical value, we reduced the masses of the up and down quarks until, under an increase of temperature, the system underwent a second-order phase transition to a quark-gluon plasma. Then we measured the response of this system to an increase in the quark density. We find that the transition is smoothened rather than sharpened. If confirmed on a finer lattice, this finding makes it unlikely for ongoing experimental searches to find a QCD critical point at small chemical potential