Show notes
Interview with Chad Norgan of Rackspace, about use of Open vSwitch at Rackspace over the years. Topics include:
- Chad's role at Rackspace and what he spends his time on.
- Shifts in where he spends his time as Open vSwitch has matured.
- Experiments with buying and writing SDN controllers and OpenFlow flows at Rackspace, including a Ryu-based chassis controller.
- SDN in two generations of Rackspace cloud, with NVP in the second generation.
- Tracing datapath flows using tools in Open vSwitch, using “
ovs-appctl ofproto/trace”, and the value of tracing for debugging a running system. - Suggestions for improving “
ovs-appctl ofproto/trace”. - Usefulness of Open vSwitch logging.
- Significant performance improvements since earlier versions, such as moving logging out of the main thread, megaflows, and eviction handling.
- Potential appliance use of DPDK, contrasted against downside for hypervisors of losing a core.
- Thoughts about importance of 64-byte packet performance in Rackspace environment, and potential of eBPF work going on at Cisco to help with that.
- Performance history of Open vSwitch versions as perceived by Nicira and Rackspace, and its evolution over time as Open vSwitch was exposed to more and more diverse production use cases.
- Open vSwitch decision for version 1.11 to completely rewrite everything in terms of megaflows, to achieve reasonable performance in important minority of cases.
- Chad's presentation on Open vSwitch performance at the Open vSwitch 2014 Fall Conference.
- Open vSwitch as the “incumbent” virtual switch.
- Generating good representative traffic for testing.
- Ixia hardware for predictable traffic generation, removing a variable from the testing equation.
- Desire for a physical hardware switch with the flexibility of Open vSwitch, with P4 switches as a possible route there.
- “
ovsdb-tool -mmm show-log” as database debugging tool.