Publications by Jens Domke

The interconnection network has a large influence on total cost, application performance, energy consumption, and overall system efficiency of a supercomputer. Unfortunately, today's routing algorithms do not utilize this important resource most efficiently. We first demonstrate this by defining the dark fiber metric as a measure of unused resource in networks. To improve the utilization, we propose scheduling-aware routing, a new technique that uses the current state of the batch system to determine a new set of network routes and so increases overall system utilization by up to 17.74%. We also show that our proposed routing increases the throughput of communication benchmarks by up to 17.6% on a practical InfiniBand installation. Our routing method is implemented in the standard InfiniBand tool set and can immediately be used to optimize systems. In fact, we are using it to improve the utilization of our production petascale supercomputer for more than one year.

@inproceedings{abc,
	abstract = {The interconnection network has a large influence on total cost, application performance, energy consumption, and overall system efficiency of a supercomputer. Unfortunately, today{\textquoteright}s routing algorithms do not utilize this important resource most efficiently. We first demonstrate this by defining the dark fiber metric as a measure of unused resource in networks. To improve the utilization, we propose scheduling-aware routing, a new technique that uses the current state of the batch system to determine a new set of network routes and so increases overall system utilization by up to 17.74\%. We also show that our proposed routing increases the throughput of communication benchmarks by up to 17.6\% on a practical InfiniBand installation. Our routing method is implemented in the standard InfiniBand tool set and can immediately be used to optimize systems. In fact, we are using it to improve the utilization of our production petascale supercomputer for more than one year.},
	author = {Jens Domke and Torsten Hoefler},
	booktitle = {Proceedings of the International Conference for High Performance Computing, Networking, Storage and Analysis},
	title = {Scheduling-Aware Routing for Supercomputers},
	venue = {Salt Lake City, UT, USA},
	year = {2016}
}

Lossless interconnection networks are omnipresent in high performance computing systems, data centers and network-on-chip architectures. Such networks require efficient and deadlock-free routing functions to utilize the available hardware. Topology-aware routing functions become increasingly inapplicable, due to irregular topologies, which either are irregular by design or as a result of hardware failures. Existing topology-agnostic routing methods either suffer from poor load balancing or are not bounded in the number of virtual channels needed to resolve deadlocks in the routing tables. We propose a novel topology-agnostic routing approach which implicitly avoids deadlocks during the path calculation instead of solving both problems separately. We present a model implementation, called Nue, of a destination-based and oblivious routing function. Nue routing heuristically optimizes the load balancing while enforcing deadlock-freedom without exceeding a given number of virtual channels, which we demonstrate based on the InfiniBand architecture.

@inproceedings{abc,
	abstract = {Lossless interconnection networks are omnipresent in high performance computing systems, data centers and network-on-chip architectures. Such networks require efficient and deadlock-free routing functions to utilize the available hardware. Topology-aware routing functions become increasingly inapplicable, due to irregular topologies, which either are irregular by design or as a result of hardware failures. Existing topology-agnostic routing methods either suffer from poor load balancing or are not bounded in the number of virtual channels needed to resolve deadlocks in the routing tables. We propose a novel topology-agnostic routing approach which implicitly avoids deadlocks during the path calculation instead of solving both problems separately. We present a model implementation, called Nue, of a destination-based and oblivious routing function. Nue routing heuristically optimizes the load balancing while enforcing deadlock-freedom without exceeding a given number of virtual channels, which we demonstrate based on the InfiniBand architecture.},
	author = {Jens Domke and Torsten Hoefler and Satoshi Matsuoka},
	booktitle = {Proceedings of the 25th ACM International Symposium on High-Performance Parallel and Distributed Computing},
	title = {Routing on the Dependency Graph: A New Approach to Deadlock-Free High-Performance Routing},
	venue = {Kyoto, Japan},
	year = {2016}
}