Welcome!

SDN Journal Authors: Elizabeth White, Yeshim Deniz, Liz McMillan, Pat Romanski, TJ Randall

Related Topics: @DevOpsSummit, SDN Journal

@DevOpsSummit: Blog Post

What is Control Plane Scripting? | @DevOpsJournal [#DevOps]

So within the realm of software-defined (everything) and DevOps one can find lengthy (and often in depth) discussions

F5 Friday: What is Control Plane Scripting?

#DevOps #SDN And more importantly, what can I do with it?

So within the realm of software-defined (everything) and DevOps one can find lengthy (and often in depth) discussions on the relevance and indeed importance of programmability to both. In the case of SDN, programmability is specifically subdivided into two areas: control plane and data path.

That's because its core premise relies on - no requires, actually - the decoupling of the two paths.

So you use the control plane to centralize the "state" of the network. What that really means is that some entity external to the data plane (or data path) is responsible for authoritatively managing (and controller) the configuration of the services that reside in the data plane. That happens either using control plane APIs (like F5's iControl) or protocols (OpFlex, OpenFlow, etc... ). This is where the ability to efficiently automate and orchestrate services comes from, resulting in the benefits of reduced risk and improved time to market touted by SDN and related architectures.

Now, what most people don't know is there's a second control plane programmability component known as control plane scripting. What control plane scripting does is allow the control plane to dynamically modify configuration and policy.

That's what F5 iCall does.

data plane control plane

Here Comes the (Computer) Science

So let's say you want to be able to dynamically do something sometimes, but not all the time. In other words, you want it to only happen when certain conditions are met, say log a tcpdump when an application experiences a failure. The "event" is "application failure". The response is "run a tcpdump and log it to X."

So what happens is we're moving along quite normally and as expected, F5 selects App Instance 1 to service a request. For some reason, App Instance 1 experiences a failure. Maybe it's a 500 Internal Server error or maybe it's a network level failure (a time out). The failure triggers the iCall script, which then executes a tcpdump and merrily sends it off to a log somewhere. Oh, and it might even send you an e-mail to let you know, cause it's thoughtful that way.

Basically iCall can perform tasks in response to a triggered event, on a periodic basis, or as a perpetual daemon-like service. iCall enables folks to react to specified events by executing services on the control plane, such as logging a full TCP stack dump on a failure, executing a specific iApp to reconfigure application network service settings, or adjusting weights on application services based on a change in health-monitoring data. iCall can be used to periodically manage backups or repopulate DNS. Additionally, perpetual services such as configuration audits can be managed simply using iCall.

The unique thing about iCall is that it can be triggered from the data plane. That means that as traffic is flowing through a service, a data path script (iRules) can trigger a control plane script (iCall). A good example is invalidating the cache. This example executes when a specific URI is invoked, but because it's programmability you have the flexibility to pretty much think of whatever trigger you'd like. For example, you could trigger on an HTTP 404 error seen on the data plane to execute an iCall script that sends an e-mail. Cause, you're thoughtful that way.

iCall is not an API, it's not data path scripting, it's control plane scripting. It's another tool in the network that enables greater flexibility and responsiveness to events that happen in real time that should be handled but often aren't because, well, you aren't fast enough to hit the button to start that TCP capture.

Control plane scripting, like data path scripting, is a programmatic means to an end. The "end" being a more operationally efficient and agile network.

Read the original blog entry...

More Stories By Lori MacVittie

Lori MacVittie is responsible for education and evangelism of application services available across F5’s entire product suite. Her role includes authorship of technical materials and participation in a number of community-based forums and industry standards organizations, among other efforts. MacVittie has extensive programming experience as an application architect, as well as network and systems development and administration expertise. Prior to joining F5, MacVittie was an award-winning Senior Technology Editor at Network Computing Magazine, where she conducted product research and evaluation focused on integration with application and network architectures, and authored articles on a variety of topics aimed at IT professionals. Her most recent area of focus included SOA-related products and architectures. She holds a B.S. in Information and Computing Science from the University of Wisconsin at Green Bay, and an M.S. in Computer Science from Nova Southeastern University.

CloudEXPO Stories
Your job is mostly boring. Many of the IT operations tasks you perform on a day-to-day basis are repetitive and dull. Utilizing automation can improve your work life, automating away the drudgery and embracing the passion for technology that got you started in the first place. In this presentation, I'll talk about what automation is, and how to approach implementing it in the context of IT Operations. Ned will discuss keys to success in the long term and include practical real-world examples. Get started on automating your way to a brighter future!
The challenges of aggregating data from consumer-oriented devices, such as wearable technologies and smart thermostats, are fairly well-understood. However, there are a new set of challenges for IoT devices that generate megabytes or gigabytes of data per second. Certainly, the infrastructure will have to change, as those volumes of data will likely overwhelm the available bandwidth for aggregating the data into a central repository. Ochandarena discusses a whole new way to think about your next-gen applications and how to address the challenges of building applications that harness all data types and sources.
Whenever a new technology hits the high points of hype, everyone starts talking about it like it will solve all their business problems. Blockchain is one of those technologies. According to Gartner's latest report on the hype cycle of emerging technologies, blockchain has just passed the peak of their hype cycle curve. If you read the news articles about it, one would think it has taken over the technology world. No disruptive technology is without its challenges and potential impediments that frequently get lost in the hype. The panel will discuss their perspective on what they see as they key challenges and/or impediments to adoption, and how they see those issues could be resolved or mitigated.
CloudEXPO New York 2018, colocated with DevOpsSUMMIT and DXWorldEXPO New York 2018 will be held November 12-13, 2018, in New York City and will bring together Cloud Computing, FinTech and Blockchain, Digital Transformation, Big Data, Internet of Things, DevOps, AI and Machine Learning to one location.
DXWorldEXPO LLC announced today that Nutanix has been named "Platinum Sponsor" of CloudEXPO | DevOpsSUMMIT | DXWorldEXPO New York, which will take place November 12-13, 2018 in New York City. Nutanix makes infrastructure invisible, elevating IT to focus on the applications and services that power their business. The Nutanix Enterprise Cloud Platform blends web-scale engineering and consumer-grade design to natively converge server, storage, virtualization and networking into a resilient, software-defined solution with rich machine intelligence.