Backdraft - A Lossless Virtual Switch that Prevents the Slow Receiver Problem

Explore a 17-minute conference talk from NSDI '22 that introduces Backdraft, a novel lossless virtual switch designed to prevent the slow receiver problem in end-host networking. Delve into the challenges of packet loss in virtual switches and its impact on application performance. Discover how Backdraft combines Dynamic Per-Flow Queuing, Doorbell queues, and a new overlay network to address these issues. Learn about the implementation of Backdraft on BESS and its performance in experiments with real applications on a 100 Gbps cluster. Gain insights into how Backdraft achieves significantly lower tail latency at the 99th percentile when compared to existing solutions.

Intro
Packet loss is a problem
Packet loss can occur in the network
Vagaries of CPU performance
The slow receiver problem
Lossless virtual switching is challenging
Backdraft: A 10,000 Ft. View
Insights of Backdraft
Slow receivers manifest at us-scale
Three components of Backdraft
Key idea behind the per flow queuing
Why do we lose packets?
Design space of the Per Flow Queuing
Dynamic Per Flow Queuing
Key idea behind doorbell queues
How does doorbell queues work?
Backdraft overlay network
Homa experiment setup
Backdraft complements Homa - RPC Completion time
Evaluating different components of
Backdraft Takeaways Slow receivers are pervasive