Existing campus network infrastructure is not designed to effectively handle the transmission of big data sets. Performance degradation in these networks is often caused by middleboxes -- appliances that enforce campus-wide policies by deeply inspecting all traffic going through the network (including big data transmissions). We are developing a Software-Defined Networking (SDN) solution for our campus network that grants privilege to science flows by dynamically calculating routes that bypass certain middleboxes to avoid the bottlenecks they create. Using the global network information provided by an SDN controller, we are developing graph databases approaches to compute custom paths that not only bypass middleboxes to achieve certain requirements (e.g., latency, bandwidth, hop-count) but also insert rules that modify packets hop-by-hop to create the illusion of standard routing/forward despite the fact that packets are being rerouted. In some cases, additional functionality needs to be added to the path using network function virtualization (NFV) techniques (e.g., NAT). To ensure that path computations are run on an up-to-date snapshot of the topology, we introduce a versioning mechanism that allows for lazy topology updates that occur only when "important" network changes take place and are requested by big data flows.
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Expanding across time to deliver bandwidth efficiency and low latency
Datacenters need networks that support both low-latency and high-bandwidth packet delivery to meet the stringent requirements of modern applications. We present Opera, a dynamic network that delivers latency-sensitive traffic quickly by relying on multi-hop forwarding in the same way as expander-graph-based approaches, but provides near-optimal bandwidth for bulk flows through direct forwarding over time-varying source-to-destination circuits. Unlike prior approaches, Opera requires no separate electrical network and no active circuit scheduling. The key to Opera's design is the rapid and deterministic reconfiguration of the network, piece-by-piece, such that at any moment in time the network implements an expander graph, yet, integrated across time, the network provides bandwidth-efficient single-hop paths between all racks. We show that Opera supports low-latency traffic with flow completion times comparable to cost-equivalent static topologies, while delivering up to 4x the bandwidth for all-to-all traffic and supporting up to 60% higher load for published datacenter workloads.
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- Award ID(s):
- 1911104
- NSF-PAR ID:
- 10181645
- Date Published:
- Journal Name:
- USENIX Symposium on Networked Systems Design and Implementation (NSDI)
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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