Towards Modeling Interconnection Networks of Exascale Systems with OMNet++

2016 2nd IEEE International Workshop on High-Performance Interconnection Networks in the Exascale and Big-Data Era (HiPINEB)

et al. 2016

The design of interconnection networks is becoming extremely important for High-Performance Computing (HPC) systems in the Exascale Era. Design decisions like the selection of the network topology, routing algorithm, fault tolerance and/or congestion control are crucial for the network performance. Besides, the interconnection network designers are also focused on creating middleware layers compatible to different network technologies, which make it possible for these technologies to interoperate. One example is the OpenFabrics Software (OFS) used in HPC for breakthrough applications that require high efficiency computing, wire-speed messaging, microsecond latencies and fast I/O for storage and file systems. OFS is compatible with several HPC interconnect technologies, like InfiniBand, iWarp or RoCE. One challenge in the design of new features for improving the interconnection network performance is to model in specific simulation tools the latency introduced by the OFS modules into the network traffic. In this paper, we present a work-in-progress methodology to combine the OFS middleware with OMNeT++based simulation tools, so that we can use some of the OFS modules, like OpenSM or ibsim, combined with simulation tools. We also propose a set of tools for analyzing the properties of different network topologies. Future work will consist on modeling other OFS modules functionality in network simulators.

Section: Methodology Descriptionmentioning

confidence: 99%

Section: Methodology Descriptionmentioning

confidence: 99%

Section: Motivationmentioning

confidence: 99%

Section: The Omnet++ Frameworkmentioning

confidence: 99%

See 2 more Smart Citations

Combining OpenFabrics Software and Simulation Tools for Modeling InfiniBand-Based Interconnection Networks

Maglione-Mathey

2016 2nd IEEE International Workshop on High-Performance Interconnection Networks in the Exascale and Big-Data Era (HiPINEB)

et al. 2016

“…The simulation tool used in our experiments, whose basics are described in detail in [26], is based on the OMNeT++ framework [27]. It models the main functionalities of interconnection networks with cycle-level accuracy, as well as different topologies and routing algorithms.…”

Section: A Simulation Modelmentioning

confidence: 99%

Combining HoL-blocking avoidance and differentiated services in high-speed interconnects

2014 21st International Conference on High Performance Computing (HiPC)

Gómez

et al. 2014

Current high-performance platforms such as Datacenters or High-Performance Computing systems rely on highspeed interconnection networks able to cope with the everincreasing communication requirements of modern applications. In particular, in high-performance systems that must offer differentiated services to applications which involve traffic prioritization, it is almost mandatory that the interconnection network provides some type of Quality-of-Service (QoS) and CongestionManagement mechanism in order to achieve the required network performance. Most current QoS and Congestion-Management mechanisms for high-speed interconnects are based on using the same kind of resources, but with different criteria, resulting in disjoint types of mechanisms. By contrast, we propose in this paper a novel, straightforward solution that leverages the resources already available in InfiniBand components (basically Service Levels and Virtual Lanes) to provide both QoS and Congestion Management at the same time. This proposal is called CHADS (Combined HoL-blocking Avoidance and Differentiated Services), and it could be applied to any network topology. From the results shown in this paper for networks configured with the novel, cost-efficient KNS hybrid topology, we can conclude that CHADS is more efficient than other schemes in reducing the interferences among packet flows that have the same or different priorities.

Providing differentiated services, congestion management, and deadlock freedom in dragonfly networks with adaptive routing

Concurrency and Computation

García

et al. 2016

SummaryThe number of endnodes in high‐performance computing systems has grown significantly in the last years. Hence, the interconnection network has become an essential issue as it may end up being the system bottleneck if it is not properly designed. In that sense, the Dragonfly topology has become very popular for interconnecting high‐performance computing systems in the last years because it offers high performance at an affordable cost. However, when using deterministic minimal‐path routing, this topology is not able to offer a high performance under certain traffic conditions. This problem can be solved by using oblivious or adaptive routing. However, there are no congestion management techniques specially tailored to Dragonfly topologies using oblivious or adaptive routing. Note that in congestion situations, the Dragonfly performance may drop because of the head‐of‐line blocking effect. This effect could be even more dangerous in systems where several applications with different priorities coexist. In this work we propose several techniques especially designed for providing differentiated services and congestion management in Dragonfly networks using oblivious or adaptive routing. First, we propose the hierarchical 3‐level queuing queuing scheme, which configures several virtual channels distributed into 3 virtual networks to reduce the head‐of‐line blocking while deadlocks derived from the routing algorithm are prevented. Second, we extend hierarchical 3‐level queuing to provide differentiated services through 2 different solutions. Finally, some experiments are performed to show the benefits obtained by using the proposed techniques.