OVS Orbit

OVS Orbit

By Ben PfaffTechnology
Download on the App Store

OVS Orbit episodes

  • Encrypting OVN Tunnels with IPsec, with Qiuyu Xiao from UNC-Chapel Hill

    Qiuyu Xiao is a Ph.D. student in the department of computer science at
    the University of North Carolina at Chapel Hill. During the summer of
    2018, he was an intern in the Open vSwitch team at VMware. This episode
    is a talk that Qiuyu gave at the end of his internship, describing his
    work on encrypted tunnels for OVN. The slides that accompanied the talk are available.

    To learn more about Qiuyu's work, visit his
    website, or contact him via email at [email protected] or on Twitter as @QiuyuX.

    OVS Orbit is produced by Ben Pfaff. The
    intro music in this episode is Drive,
    featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper
    music is Yeah Ant
    featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro
    music is Space
    Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All
    content is licensed under a Creative Commons Attribution 3.0
    Unported (CC BY 3.0) license.

    54 min
  • Introduction to OVSDB, Part 2

    This episode, recorded in April 2018, was the third in a series of
    internal VMware tech talks about Open vSwitch. This episode is
    particularly about OVSDB, the Open vSwitch Database, and particularly
    about OVSDB from the viewpoint of the client. It talks about the C
    client library, including how it represents data, the usual way to work
    with it, and how it interacts with the OVSDB server. It also covers how
    the C client library supports preparing transactions to send to the
    server.

    Part of the talk dissects and explains an OVSDB JSON-RPC transaction
    created by ovs-vsctl. You can see a similar transaction by
    running make sandbox in an OVS tree, then ovs-vsctl
    -vjsonrpc add-br br0 inside the sandbox. Look for the
    transact operation, Or look at this
    example, which has been put through a JSON pretty-printer for
    legibility.

    The talk concludes with several minutes of questions. One of the
    questions discusses the C IDL's rendering of the AutoAttach table. You
    can find this at the top of the file here.

    Part 1, in episode 55, covered OVSDB from the server
    and network protocol point of view.

    OVS Orbit is produced by Ben Pfaff. The
    intro music in this episode is Drive,
    featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper
    music is Yeah Ant
    featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro
    music is Space
    Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All
    content is licensed under a Creative Commons Attribution 3.0
    Unported (CC BY 3.0) license.

    55 min
  • Personalized Pseudonyms for Servers in the Cloud, with Qiuyu Xiao from UNC-Chapel Hill

    Qiuyu Xiao is a PhD student studying computer science at the University
    of North Carolina at Chapel Hill. This episode is a talk that Qiuyu gave
    at VMware in May. It is based on the paper “Personalized Pseudonyms for
    Servers in the Cloud,” by Qiuyu Xiao, Michael K. Reiter, and Yinqian
    Zhangyinqian, originally published in 2017 at Proceedings on
    Privacy Enhancing Technologies.

    You may wish to follow along with Qiuyu's slides.

    The paper's abstract is:

    A considerable and growing fraction of servers, especially of web
    servers, is hosted in compute clouds. In this paper we opportunistically
    leverage this trend to improve privacy of clients from network attackers
    residing between the clients and the cloud: We design a system that can
    be deployed by the cloud operator to prevent a network adversary from
    determining which of the cloud’s tenant servers a client is
    accessing. The core innovation in our design is a PoPSiCl (pronounced
    “popsicle”), a persistent pseudonym for a tenant server that can be used
    by a single client to access the server, whose real identity is protected
    by the cloud from both passive and active network attackers. When
    instantiated for TLS-based access to web servers, our design works with
    all major browsers and requires no additional client-side software and
    minimal changes to the client user experience. Moreover, changes to
    tenant servers can be hidden in supporting software (operating systems
    and web-programming frameworks) without imposing on web-content
    development. Perhaps most notably, our system boosts privacy with minimal
    impact to web-browsing performance, after some initial setup during a
    user’s first access to each web server.

    You can reach Qiuyu at [email protected] or on Twitter as @QiuyuX.

    Related episodes.

    OVS Orbit is produced by Ben Pfaff. The
    intro music in this episode is Drive,
    featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper
    music is Yeah Ant
    featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro
    music is Space
    Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All
    content is licensed under a Creative Commons Attribution 3.0
    Unported (CC BY 3.0) license.

    41 min
  • Generic Linux Debugging, with Ansis Atteka from VMware

    Ansis Atteka is a developer on the Open vSwitch team at VMware. This
    episode is a recording of a talk that Ansis gave at VMware in May. He
    covers techniques for debugging on Linux, in particular how to trace
    through processes using strace, trace-cmd, and
    other tools.

    You may want to follow along with Ansis's slides.

    You can contact Ansis at [email protected].

    OVS Orbit is produced by Ben Pfaff. The
    intro music in this episode is Drive,
    featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper
    music is Yeah Ant
    featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro
    music is Space
    Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All
    content is licensed under a Creative Commons Attribution 3.0
    Unported (CC BY 3.0) license.

    26 min
  • Networking with OVS at DigitalOcean, with Matt Layher and Armando Migliaccio from DigitalOcean

    Matt Layher and Armando Migliaccio are
    engineers focusing on networking at DigitalOcean, a cloud service
    provider. In April, Justin
    Pettit and I sat down with them at DigitalOcean HQ in New York City.
    This episode is our discussion, which ranges from how DO first began
    using Open vSwitch, the DO approach to network control, to scale and
    performance issues, upgrade strategy, and the Open vSwitch code that
    DigitalOcean itself is working to contribute.

    Previously, Matt gave a talk at Open vSwitch 2017
    Fall Conference about the use of Go with Open vSwitch at
    DigitalOcean.

    OVS Orbit is produced by Ben Pfaff. The
    intro music in this episode is Drive,
    featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper
    music is Yeah Ant
    featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro
    music is Space
    Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All
    content is licensed under a Creative Commons Attribution 3.0
    Unported (CC BY 3.0) license.

    40 min
  • Oko: Extending Open vSwitch with Stateful Filters, with Paul Chaignon from Orange Labs and Inria Nancy

    Paul Chaignon is a grad student at Orange and Inria. In this episode,
    Paul talks about Oko: Extending Open
    vSwitch with Stateful Filters, a paper written with co-authors Kahina
    Lazri, Jérôme François, Thibault Delmas, and Olivier Festor. Paul
    presented this research at SOSR '18 in March
    2018. The paper has the following abstract:

    With the Software-Defined Networking paradigm, software switches
    emerged as the new edge of datacenter networks. The widely adopted Open
    vSwitch implements the OpenFlow forwarding model; its simple
    match-action abstraction eases network management, while providing
    enough flexibility to define complex forwarding pipelines. OpenFlow,
    however, cannot express the many packets processing algorithms required
    for traffic measurement, network security, or congestion diagnosis, as
    it lacks a persistent state and basic arithmetic and logic operations.

    This paper presents Oko, an extension of Open vSwitch that enables
    runtime integration of stateful filtering and monitoring
    functionalities based on Berkeley Packet Filter (BPF) programs into the
    OpenFlow pipeline. BPF programs attached to OpenFlow rules act as
    intelligent filters over packets, while leaving the packets
    unmodified. This approach enables the transparent extension of Open
    vSwitch's flow caching architecture, retaining its high-performance
    benefits. Furthermore, the use of BPF allows for safe runtime extension
    and prevention of switch failures due to faulty programs.

    We compare our implementation based on Open vSwitch-DPDK to existing
    approaches with comparable isolation properties and measure a near 2x
    improvement of performance.

    You can contact Paul on Twitter as @pchaigno.

    OVS Orbit is produced by Ben Pfaff. The
    intro music in this episode is Drive,
    featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper
    music is Yeah Ant
    featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro
    music is Space
    Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All
    content is licensed under a Creative Commons Attribution 3.0
    Unported (CC BY 3.0) license.

    24 min
  • Incremental Processing with ovn-controller, with Han Zhou from eBay

    Han Zhou is an architect working on highly scalable and reliable SDN
    solutions for eBay's cloud infrastructure. He is an active contributor
    in OpenStack and OVS/OVN. Before eBay, he has been working in networking
    area for more than 10 years in Cisco and Nokia.

    In OVN, the ovn-controller daemon runs on each hypervisor.
    It obtains logical flows from the OVN southbound database, transforms
    them into "physical flows," and pushes the physical flows into
    ovs-vswitchd over an OpenFlow connection. In the current
    implementation, whenever any of the tables in the OVN southbound database
    changed, the daemon would fully recompute all of the physical flows to be
    pushed into ovs-vswitchd. With a sufficiently large setup,
    this is expensive. This talk is about Han's patches to make computation
    in ovn-controller incremental, so that a small change in the
    input causes only a small amount of computation.

    Some of the talk is easier to follow if you view the slides (PDF).

    Han was previously featured in OVS Orbit in episode
    36, where he spoke about Baker, an approach used by eBay to combine
    OVN with Kubernetes.

    OVS Orbit is produced by Ben Pfaff. The
    intro music in this episode is Drive,
    featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper
    music is Yeah Ant
    featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro
    music is Space
    Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All
    content is licensed under a Creative Commons Attribution 3.0
    Unported (CC BY 3.0) license.

    29 min
  • Toward Leaner, Faster ovn-northd, with Leonid Ryzhyk from VMware Research Group

    Leonid Ryzhyk is a senior researcher in the VMware Research Group. The
    main theme of his work is applying formal methods to build better
    operating systems and networks. Before joining VMware, Leonid received
    his PhD from University of New South Wales and NICTA. Leonid has also
    worked as a researcher at NICTA, as a postdoc at University of Toronto
    and at Carnegie Mellon University, and as a researcher at Samsung
    Research America.

    In OVN, the ovn-northd daemon acts as an interface and a
    translator between OVN's northbound and southbound databases. With the
    existing implementation, any change in the northbound database causes
    ovn-northd to do a full recomputation of the complete
    contents of the southbound database. For a large network, this is
    slow—it can take multiple seconds of CPU time—regardless of
    the size of the change in the northbound database. Therefore, even a
    small change, such as adding or removing a single port or a single VM,
    can take a relatively long time to be realized in the network.

    In this talk, Leonid presents a prototype for a solution to the problem.
    The solution implements incremental computation using a system called Differential
    Dataflow, which is based on the Datalog language for
    database queries. Because Datalog is not a particularly friendly
    language for developers who are not already accustomed to it, Leonid also
    layered syntactic sugar over it called FTL, for Flow Template Language,
    which is inspired by the FLWOR syntax from XQuery.

    Some of the talk is easier to follow if you view the slides (PDF).

    You can contact Leonid via email at [email protected].

    Leonid previously appeared in OVS Orbit in episode 44
    on the Cocoon-2 network programming system. Episode 5,
    with Teemu Koponen and Yusheng Wang, touched on related concepts with its
    coverage of the nlog language which is also based on Datalog.

    OVS Orbit is produced by Ben Pfaff. The
    intro music in this episode is Drive,
    featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper
    music is Yeah Ant
    featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro
    music is Space
    Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All
    content is licensed under a Creative Commons Attribution 3.0
    Unported (CC BY 3.0) license.

    34 min
  • OpenFaaS, with Alex Ellis from VMware

    Alex Ellis founded and leads the OpenFaaS project, which is an open
    source implementation of a serverless
    framework. This episode is an interview with Alex. We talk about
    serverless functions and OpenFaaS, how OpenFaaS compares to other
    serverless frameworks, how networking works in OpenFaaS, open source
    communities, and other related topics. We also take on a couple of
    questions asked by listeners on Twitter.

    For more information about OpenFaaS, visit openfaas.com. To get in touch with
    Alex, you can tweet to him as @alexellisuk.

    OVS Orbit is produced by Ben Pfaff. The
    intro music in this episode is Drive,
    featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper
    music is Yeah Ant
    featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro
    music is Space
    Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All
    content is licensed under a Creative Commons Attribution 3.0
    Unported (CC BY 3.0) license.

    51 min
  • Flow Translation

    This is the third in a series of Open vSwitch tech talks that we are
    starting to run internally at VMware every week or two. This episode is
    about flow translation, the process that OVS follows when a packet
    arrives in the software switch that does not match any already
    established entry in the OVS datapath cache (the megaflow cache).

    The translation process has two goals. First, it figures out what to do
    with the particular packet being processed Second, it determines what
    class of packets similar to this packet can be treated the same way. The
    former determination is generally applied directly to the packet in
    question, and the latter is used to add a new cache entry (megaflow) to
    the datapath.

    The main source files involved in translation are ofproto-dpif-xlate.c and ofproto-dpif-xlate.h.

    In addition to the translation process itself, the talk covers some uses
    of relevant tools: ovs-dpctl dump-flows and ovs-appctl
    dpctl/dump-flows for viewing datapath cache entries, and
    ovs-appctl ofproto/trace for understanding how cache entries
    are devised and populated and playing "what-if?" games. These are
    documented in the ovs-vswitchd and ovs-dpctl
    manpages.

    The NSDI 2015 paper The
    Design and Implementation of Open vSwitch covers in detail how Open
    vSwitch caches translations.

    OVS Orbit is produced by Ben Pfaff. The
    intro music in this episode is Drive,
    featuring cdk and DarrylJ, copyright 2013, 2016 by Alex. The bumper
    music is Yeah Ant
    featuring Wired Ant and Javolenus, copyright 2013 by Speck. The outro
    music is Space
    Bazooka featuring Doxen Zsigmond, copyright 2013 by Kirkoid. All
    content is licensed under a Creative Commons Attribution 3.0
    Unported (CC BY 3.0) license.

    53 min

About OVS Orbit

From the publisher's feed

Interviews and topics of interest to Open vSwitch developers and users, published twice a month, hosted and produced by Ben Pfaff.