Thursday, August 15, 2013

SIGCOMM2013: Got Loss? Get zOVN!

Presenter: Daniel Crisan
Co-authors: Robert Birke, Gilles Cressier, Cyriel Minkenberg and Mitch Gusat 

This paper does loss identification and characterization in virtualized data center networks
This paper quantifies the losses for several common combinations of hypervisors and virtual switches, and shows their detrimental effects on application performance. The authors propose a zero-loss Overlay Virtual Network (zOVN) designed to reduce the query and flow completion time of latency-sensitive datacenter applications. They describe its architecture and detail the design of its key component, the zVALE lossless virtual switch.

As part of the evaluation, they implemented a zOVN prototype and benchmark it with Partition-Aggregate in two testbeds, achieving an up to 15-fold reduction of the mean completion time with three widespread TCP versions. For larger-scale validation and deeper introspection into zOVN, they developed an OMNeT++ model for accurate cross layer simulations of a virtualized datacenter. 


Q: Whenever the queue is full, you put the hypervisor to sleep? How do you deal with dead lock situations?

A: Multiple threads.

Q: How many VMs per CPU do you use?

A: One VM at the sender and one at the receiver.