Distributed Control Plane in a Datacenter Median flow arrival rate requires 1-5 controllers, peak requires 150* Distributed control plane should grow and shrink Flow arrival rates vary across switches and time Need a switch migration (handover) protocol * Calculations based on Benson et al, IMC 2010
Distributed SDN Control Plane Physical Network Infrastructure Core Controller Module Distributed Data Store (e.g., Hazelcast) Controller Node 1Controller Node 2 Application 1Application 2 Core Controller Module Application 1Application 2 Hazelcast Client Stub
Next Steps Build a control loop and algorithms for dynamically: Changing switch-controller mapping based Growing and shrinking distributed controller Thanks! Questions?
Need title for this slide For a data center with 100K hosts: Peak flow arrival rate = 300M* flows/sec Median flow arrival rate = 1.5-10M* flows/sec Impossible to predict flow arrival rates at a switch Implications: Distributed controller needs to grow and shrink Need a switch migration protocol * From Benson et al, IMC 2010
New Problems in Distributed SDN Controllers How to manage distributed state? Where to place controllers? How to write distributed controller applications? How many controllers? Which switch connects to which controller?
How to manage distributed state? Where to place controllers? How to write distributed controller applications? How many controllers? Which switch connects to which controller?
Distributed SDN Controller Distributed Global Network State Physical Network Infrastructure Application 1 Application 2 Application 3 Application 4
Problem Statement How many servers? How to determine switch- controller mapping?
Naïve Switch Migration//Change title? SLAVEMASTER SLAVE Role Change to Master SLAVE