The full text of this article:

Application-bypass reduction for large-scale clusters
by Adam Wagner, Darius Buntinas, Ron Brightwell, Dhabaleswar K. Panda
International Journal of High Performance Computing and Networking (IJHPCN), Vol. 2, No. 2/3/4, 2004
Abstract: Process skew is an important factor in the performance of parallel applications, especially in large-scale clusters. Reduction is a common collective operation which, by its nature, introduces implicit synchronisation between the processes involved in the communication and is therefore highly susceptible to performance degradation due to process skew. A collective operation with application-bypass does not require the application to block in order for the operation to make progress. Application-bypass collective operations are therefore highly tolerant of skew. In this paper, we describe the design and implementation of an application-bypass version of the reduction operation in MPICH over GM. We evaluate our implementation on a 32-node cluster. Under conditions of process skew we find a factor of improvement of up to 5.1 for our application-bypass reduction versus the default MPICH implementation. In addition, we see that this factor of improvement increases with system size, indicating that the application-bypass implementation is more scalable and skew-tolerant than the default non-application-bypass version. This framework promises design and development of high-performance and scalable collective communication libraries for next-generation large-scale clusters.

is only available to individual subscribers or to users at subscribing institutions.

Pay per view: If you are not a Subscriber and you just want to read the full contents of this article, please click here to purchase online access to the full-text of this article. Please allow 3 days + mailing time. Current price for article is Thirty Euros (€30)

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of High Performance Computing and Networking (IJHPCN) journal, that have been redirected here, please check if you have a registered username/password subscription with Inderscience. If that is the case, please Login:

If you are not yet a Subscriber to International Journal of High Performance Computing and Networking (IJHPCN) journal, you can subscribe by following a few simple and quick steps. A subscription will give you complete access to all articles in the current issue, as well as to all articles in the previous three years, where applicable. Click here to subscribe.

Should you experience further difficulties or have any enquiries, please email subs@inderscience.com