FastLane: Agile Drop Notification for Datacenter Networks
Abstract
The drive towards richer and more interactive web content places increasingly stringent requirements on datacenter networks. The speed with which such networks respond to packet drops limits their ability to meet high-percentile flow completion time SLOs. Indirect notifications to packet drops (e.g., duplicates in an end-to-end acknowledgment sequence) are an important limitation to the agility of response to packet drops. We propose FastLane, a new in-network drop notification mechanism. FastLane enhances switches to send high-priority per-flow drop notifications to sources, thus informing sources as quickly as possible. Consequently, sources can retransmit packets sooner and throttle transmission rates earlier. Sources also can make better decisions, given more precise information and the ability to differentiate between out-of-order delivery and packet loss. We demonstrate, through simulation and implementation, that FastLane reduces 99.9th percentile completion times of short flows by up to 75%. These benefits come at minimal cost -- safeguards ensure that FastLane consumes no more that 1% of bandwidth and 2.5% of buffers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 23, 2013
- Accession Number
- ADA593579
Entities
People
- Amin Vahdat
- Anand P. Iyer
- David Zats
- Ganesh Ananthanarayanan
- Ion Stoica
- Randy H. Katz
Organizations
- University of California, Berkeley