Efficient Redundancy Techniques to Reduce Delay in Cloud Systems

ECE Seminar: Efficient Redundancy Techniques to Reduce Delay in Cloud Systems

Starts at: October 19, 2017 4:30 PM

Ends at: 6:00 PM

Location: SH 125

Speaker: Dr. Gauri Joshi

Affiliation: Assistant Professor

Link to Abstract



Ensuring fast and seamless service to users is critical for today's cloud services. However, guaranteeing fast response can be challenging due to random service delays that are common in today's data centers. In this talk I explore the use the redundancy to combat such service variability. For example, replicating a computing task at multiple servers and then waiting for the earliest copy saves service time. But the redundant tasks can cost more computing resources and also delay subsequent tasks. I present a queueing-theoretic framework to answer fundamental questions such as:

  1. How many replicas to launch?
  2. Which queues to join?
  3. When to issue and cancel the replicas?

This framework reveals surprising regimes where replication reduces both delay as well as resource cost. The task replication idea can also be generalized to analyze latency in content download from erasure coded storage. More broadly, this work lays the theoretical foundation for studying queues with redundancy, uncovering many interesting future directions in cloud infrastructure, crowdsourcing and beyond.