558,415 research outputs found
Minimizing synchronizations in sparse iterative solvers for distributed supercomputers
Eliminating synchronizations is one of the important techniques related to minimizing communications for modern high performance computing. This paper discusses principles of reducing communications due to global synchronizations in sparse iterative solvers on distributed supercomputers. We demonstrates how to minimizing global synchronizations by rescheduling a typical Krylov subspace method. The benefit of minimizing synchronizations is shown in theoretical analysis and is verified by numerical experiments using up to 900 processors. The experiments also show the communication complexity for some structured sparse matrix vector multiplications and global communications in the underlying supercomputers are in the order P1/2.5 and P4/5 respectively, where P is the number of processors and the experiments were carried on a Dawning 5000A
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
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