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.
Chad can be contacted at @chadnorgan on Twitter, as
BeardyMcBeard on the freenode IRC
network
OVS Orbit is produced by Ben Pfaff. The
intro and bumper music is Electro
Deluxe, featuring Gurdonack, copyright 2014 by My Free Mickey. The
outro music is Girls like
you, featuring Thespinwires, copyright 2014 by Stefan Kartenberg.
All content is licensed under a Creative Commons Attribution 3.0
Unported (CC BY 3.0) license.
