IPA: invariant-preserving applications for weakly consistent replicated databases

IPA: invariant-preserving applications for weakly consistent replicated databases Balegas et al., VLDB’19

IPA for developers, happy days!

Last we week looked at automating checks for invariant confluence, and extending the set of cases where we can show that an object is indeed invariant confluent. I’m not going to re-cover that background in this write-up, so I suggest you head over there for a quick catch-up before reading on if you missed it first time around.

Today’s paper is very much in same spirit, building on the same foundation of invariant confluence (I-Confluence), and also on Indigo which introduced an annotation model for application invariants, a invariant violation avoidance mechanism using lock reservations and escrows, and limited support for repairing violations that do happen.

With Invariant-Preserving Applications (IPAs), Balegas et al. introduce new mechanisms for avoiding invariant violations and for repairing them when detected, based on CRDTs. There’s also a very nice looking developer workflow to help ensure you’ve got all the bases covered. At the end of the day, you get the dual benefit of higher throughput and lower latency (as compared to coordination-based approaches) coupled with knowing that there isn’t some nasty invariant-violating concurrency bug waiting Continue reading

Cumulus content roundup: Summer 2019

Summer has flown by and you may have missed some of the great content that was published. Don’t worry, you can catch up on some of our favorite podcasts, blog posts, and articles below. So settle in and then dive into all things open networking!

From Cumulus Networks:

Customizing your network: Take a quick look at the types of automation available in Linux, from basic to dynamic, and how these automation capabilities help to enable data center-wide orchestration here.

Kernel of Truth podcast: Network monitoring: When it comes to network monitoring, have you run into a “switch that cried wolf?”Kernel of Truth host Brian O’Sullivan is joined by two new guests to the podcast Justin Betz & Faye Ly to chat more about networking monitoring here.

Best practices: MLAG backup IP: We cover the best ways to build a redundant backup IP link for multi-chassis link aggregation (MLAG).

Exploring Batfish with Cumulus – part one: With Batfish supporting Cumulus Networks this year, we show how it can fit into pipelines & replace or complement existing testing strategies in part one of a two-part series.

Kernel of Truth podcast: Innovation in the data center: Spiderman aka Rama Continue reading

ClearOS Installation on QEMU

ClearOS is an operating system based on CentOS for use in small and medium enterprises as a network gateway and network server with a web-based administration interface.

ClearOS in Gateway mode acts as a firewall, gateway and server on a local network. The tutorial provides installation and configuration steps for deployement of ClearOS on QEMU VM. We will later connect ClearOS QEMU VM into GNS3 network topology in order to test  features such as application traffic filtering and transparent proxy with user authentication.

Software Used:
Host OS: Kubuntu Linux 18.04.1 LTS with Qemu 3.0.0 installed and kvm-intel module loaded
Guest OS: ClearOS 7.5.0 x86_64

1. Preparing Host Network Infrastructure

As we are going to  install ClearOS guest QEMU VM in a gateway mode,  your host should have two network adapters available. (Picture 1). In our case, the first ClearOS guest network interface ens3 will be defined as LAN type during ClearOS installation. The second guest interface ens4 will be defined as External and used for connection to SOHO network. We will bridge the interface ens4 with the host interface enp4s0f2 using iproute utility. But first, we need to create tap interfaces tap0 and Continue reading

Thread on the OSI model is a lie

I had a Twitter thread on the OSI model. Below it's compiled into one blogpost
Yea, I've got 3 hours to kill here in this airport lounge waiting for the next leg of my flight, so let's discuss the "OSI Model". There's no such thing. What they taught you is a lie, and they knew it was a lie, and they didn't care, because they are jerks.
You know what REALLY happened when the kid pointed out the king was wearing no clothes? The kid was punished. Nobody cared. And the king went on wearing the same thing, which everyone agreed was made from the finest of cloth.
The OSI Model was created by international standards organization for an alternative internet that was too complicated to ever work, and which never worked, and which never came to pass.
Sure, when they created the OSI Model, the Internet layered model already existed, so they made sure to include today's Internet as part of their model. But the focus and intent of the OSI's efforts was on dumb networking concepts that worked differently from the Internet.
OSI wanted a "connection-oriented network layer", one that worked like the telephone system, where every switch Continue reading

Thread on network input parsers

This blogpost contains a long Twitter thread on input parsers. I thought I'd copy the thread here as a blogpost.
I am spending far too long on this chapter on "parsers". It's this huge gaping hole in Computer Science where academics don't realize it's a thing. It's like physics missing one of Newton's laws, or medicine ignoring broken bones, or chemistry ignoring fluorine.
The problem is that without existing templates of how "parsing" should be taught, it's really hard coming up with a structure for describing it from scratch.
"Langsec" has the best model, but at the same time, it's a bit abstract ("input is a language that drives computation"), so I want to ease into it with practical examples for programmers.
Among the needed steps is to stamp out everything you were taught in C/C++ about pointer-arithmetic and overlaying internal packed structures onto external data. Big-endian vs. little-endian isn't confusing -- it's only made confusing because you were taught it wrongly.
Hmmm. I already see a problem with these tweets. People assume I mean "parsing programming languages", like in the Dragon book. Instead, I mean parsing all input, such as IP headers, PDF files, X.509 certificates, and so Continue reading

Heavy Networking 468: Making The Business Case For SD-WAN

Building a business case for SD-WAN involves more than just anticipating savings by moving from private circuits to business broadband connections. On today's Heavy Networking, we look at how to tie SD-WAN capabilities to business benefits, what to consider when developing a business case, how measure ROI, and more with guest Jason Gintert.

The post Heavy Networking 468: Making The Business Case For SD-WAN appeared first on Packet Pushers.

HPE introduces VMware services on GreenLake

HP Enterprise (HPE) has been aggressively promoting its GreenLake IT consumption model since it was introduced last year. GreenLake is a pay-per-use consumption model where the customer does not take ownership of the hardware but merely leases it and pays only for their use, which is metered.Consumption models have become popular among OEMs looking to keep customers that are anxious to get out of owning expensive assets, such as servers. Dell EMC has its own program called Flex on Demand, and Lenovo has ThinkAgile CP.To read this article in full, please click here

HPE introduces VMware services on GreenLake

HP Enterprise (HPE) has been aggressively promoting its GreenLake IT consumption model since it was introduced last year. GreenLake is a pay-per-use consumption model where the customer does not take ownership of the hardware but merely leases it and pays only for their use, which is metered.Consumption models have become popular among OEMs looking to keep customers that are anxious to get out of owning expensive assets, such as servers. Dell EMC has its own program called Flex on Demand, and Lenovo has ThinkAgile CP.To read this article in full, please click here

Weekly Wrap: AT&T CEO Donovan Departs After Paving SDN Foundation

Weekly Wrap for Aug. 30, 2019: AT&T CEO John Donovan gives his notice; VMware bets the farm on...

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BrandPost: Every business is a technology business

Success for an NFL franchise involves the cultivation of a variety of core competencies both on and off the field. Recently I had the opportunity to spend time with the Seattle Seahawks organization and I was surprised by the extent to which the team utilizes data and digital tools to drive continuous improvements within their core competencies.But then why should I be surprised? Let’s face it, today, every business is a technology business. The Seahawks are no different. They are, like many other companies, investing in digital technologies to improve the product on the field and the fan experience in the stands.Data literacy is a core competency the Seahawks have added to their business. I won’t give away any trade secrets, but let’s take a high-level look at three ways this core competency creates competitive advantage.To read this article in full, please click here

CDNetworks Drives Kubernetes to the Edge

The CDN's Edge Computing Platform Service is built on Kubernetes and Docker using a container...

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Broadcom Releases PCIe Switches for Data Centers

Broadcom claims its PEX88000 family of switches are "ideal for high-throughput and low-latency...

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Cisco Patches Critical Bug in REST API Container

Cisco issued a patch for a critical bug in its IOS XE operating system that could allow a remote...

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Positioning Policy Properly

Who owns the network policy for your organization? How about the security policy?Identity policy? Sound like easy questions, don’t they? The first two are pretty standard. The last generally comes down to one or two different teams depending upon how much Active Directory you have deployed. But have you ever really thought about why?

During Future:NET this week, those poll questions were asked to an audience of advanced networking community members. The answers pretty much fell in line with what I was expecting to see. But then I started to wonder about the reasons behind those decisions. And I realized that in a world full of cloud and DevOps/SecOps/OpsOps people, we need to get away from teams owning policy and have policy owned by a separate team.

Specters of the Past

Where does the networking policy live? Most people will jump right in with a list of networking gear. Port profiles live on switches. Routing tables live on routers. Networking policy is executed in hardware. Even if the policy is programmed somewhere else.

What about security policy? Firewalls are probably the first thing that come to mind. More advanced organizations have a ton of software that scans for security Continue reading

Beyond the Palm Trees: Local Action Key to Fast, Affordable and Reliable Internet Solutions in Rural Hawai’i

To many North Americans, Hawai’i is a place of beaches, resorts, surfing, rainforests, and volcanoes — it’s a vacation destination.

But despite its tourism infrastructure and economy, Native Hawaiian communities in the far-flung chain of more than 130 islands face many of the same Internet connectivity challenges as Indigenous communities in Canada and the continental United States. And for a variety of economic, policy and geographic reasons, it is often excluded from efforts to improve access for Indigenous, rural and remote communities.

The Internet Society believes the Internet is for everyone and works with underserved communities to find and create local access solutions in some of the hardest-to-reach places on earth. What’s exciting is that despite the different geographic landscapes, the same community-led solution underway to improve Internet access in the high Arctic could also help Native Hawaiians carve their own path to better connectivity.

That’s why, in 2019, the Internet Society is holding its third annual Indigenous Connectivity Summit (ICS) in Hawai’i.

Including Indigenous voices in the planning and solutions that shape the Internet is a vital part of closing the digital divide. Previous summits in Santa Fe, New Mexico, in 2017, and Inuvik, Northwest Territories, Canada, Continue reading

Top 12 Questions from the Docker Enterprise 3.0 Webinar Series

Earlier in August, we hosted a series of virtual events to introduce Docker Enterprise 3.0. Thousands of you registered and joined us, and many of you asked great questions. This blog contains the top questions and answers from the event series.

Docker Enterprise in the Cloud, On-Prem, with Kubernetes

Q: Can Docker Enterprise be used on AWS and other cloud providers?

A: Yes! Docker Enterprise, including the Docker Universal Control Plane (UCP) and Docker Trusted Registry (DTR), can be deployed to any of the leading cloud environments, including AWS, Azure and GCP. With Docker Enterprise 3.0, we also launched the Docker Cluster CLI plugin for use with Docker Certified Infrastructure. The plugin (now supporting AWS and Azure) allows for simple installation and upgrading of Docker Enterprise on selected cloud providers.

Q: Is Docker Cluster only available in the public cloud, or is it possible to add local machines or VMs?

A: Additional support for VMware vSphere environments is coming shortly. If you have other platforms that need to be supported, please engage with your account team to provide that feedback!

Q: Does Docker Kubernetes Service (DKS) work with both on-premises and other Kubernetes environments such as EKS, AKS, Continue reading

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