Distributed consensus revised – Part II

Distributed consensus revised (part II) Howard, PhD thesis

In today’s post we’re going to be looking at chapter 3 of Dr Howard’s thesis, which is a tour (“systematisation of knowledge”, SoK) of some of the major known revisions to the classic Paxos algorithm.

Negative responses (NACKs)

In classic Paxos acceptors only send replies to proposer messages with an epoch greater than or equal to the acceptors last promised epoch (Property 6). The algorithms relies on timeouts to determine when a proposer abandons the current phase and retries with a new epoch number. We can eliminate the timeout delays by adding negative responses, for example no\_promise(e) and no\_accept(e), to be sent by the acceptor in response to prepare or propose messages with an invalid epoch number. These negative acknowledgements (NACKS) can also include further information such as the acceptor’s last promised epoch and last accepted proposal value. (There’s no point a proposer retrying with a new epoch less than the acceptor’s last promised one for example).

NACKs have replaced timeouts as we assume that messages are eventually delivered. We can therefore remove the synchrony assumptions from our progress proof.

Bypassing phase two

If a proposer learns during phase one that a value Continue reading

The Mythical Eight Hour Workday

I haven’t tracked my time in many years. I’ve always felt the practice was a nuisance. Hey, I’m busy. I have a lot to do. I’m working on it. Don’t distract me with a time sheet. You know what I do, boss, right? Do I really have to document my daily doings?

Working for myself means I don’t have to perform such trivial tasks, and of course, I don’t. However, I have been wondering over the last month where my workday goes. Often, it feels like I park my tush in my office chair, begin working on tasks, and then the day is suddenly over.

Except that often, the day isn’t over. My workday ends when I’ve accomplished everything I need to for that day. Eight hours gone by? Whatever. Head down. Keep at it. Get everything done. The list won’t get shorter tomorrow. If I want to get paid, I have to get my work done.

The Final Countdown

With more days than I want falling into a pattern of working more hours than I’d like, I’ve gotten serious about determining what the problem is. Do I need to turn away projects? Should I hire someone to handle some Continue reading

The 10 most powerful companies in enterprise networking

Enterprises recognize that all of the new technologies they want to deploy – IoT, edge computing, serverless, containers, hybrid cloud, and AI – require a robust, flexible, secure, self-healing, software-driven network. And the industry has responded with fresh new approaches such as software-defined networking (SDN), SD-WAN, hyperconverged infrastructure (HCI) and intent-based networking.To read this article in full, please click here

The 10 most powerful companies in enterprise networking

Enterprises recognize that all of the new technologies they want to deploy – IoT, edge computing, serverless, containers, hybrid cloud, and AI – require a robust, flexible, secure, self-healing, software-driven network. And the industry has responded with fresh new approaches such as software-defined networking (SDN), SD-WAN, hyperconverged infrastructure (HCI) and intent-based networking.To read this article in full, please click here

Server shipments to pick up in the second half of 2019

Global server shipments are not expected to return to growth momentum until the third quarter or even the fourth quarter of 2019, according to Taiwan-based tech news site DigiTimes, which cited unnamed server supply chain sources. The one bright spot remains cloud providers like Amazon, Google, and Facebook, which continue their buying binge.Normally I’d be reluctant to cite such a questionable source, but given most of the OEMs and ODMs are based in Taiwan and DigiTimes (the article is behind a paywall so I cannot link) has shown it has connections to them, I’m inclined to believe them.Quanta Computer chairman Barry Lam told the publication that Quanta's shipments of cloud servers have risen steadily, compared to sharp declines in shipments of enterprise servers. Lam continued that enterprise servers command only 1-2% of the firm's total server shipments.To read this article in full, please click here

Server shipments to pick up in the second half of 2019

Global server shipments are not expected to return to growth momentum until the third quarter or even the fourth quarter of 2019, according to Taiwan-based tech news site DigiTimes, which cited unnamed server supply chain sources. The one bright spot remains cloud providers like Amazon, Google, and Facebook, which continue their buying binge.Normally I’d be reluctant to cite such a questionable source, but given most of the OEMs and ODMs are based in Taiwan and DigiTimes (the article is behind a paywall so I cannot link) has shown it has connections to them, I’m inclined to believe them.Quanta Computer chairman Barry Lam told the publication that Quanta's shipments of cloud servers have risen steadily, compared to sharp declines in shipments of enterprise servers. Lam continued that enterprise servers command only 1-2% of the firm's total server shipments.To read this article in full, please click here

Red Hat Summit 2019: RHEL 8 arrives

Red Hat Summit 2019 is off to an exciting start. The conference, running from today until Thursday in Boston, is already tickling attendees’ fancies by announcing some very exciting developments.The first is Red Hat Enterprise Linux (RHEL) 8 — available now for everything from bare-metal servers and Linux containers to public and private clouds. [ Two-Minute Linux Tips: Learn how to master a host of Linux commands in these 2-minute video tutorials ] RHEL 8 introduces Application Streams, which allow languages, frameworks, and developer tools to be updated frequently without impacting the core resources that have made Red Hat Enterprise Linux an enterprise benchmark. This feature brings quick developer innovation and production stability into the OS.To read this article in full, please click here

Some IT pros say they have too much data

A new survey has found that a growing number of IT professionals have too many data sources to even count, and they are spending more and more time just wrestling that data into usable condition.Ivanti, an IT asset management firm, surveyed 400 IT professionals on their data situation and found IT faces numerous challenges when it comes to siloes, data, and implementation. The key takeaway is data overload is starting to overwhelm IT managers and data lakes are turning into data oceans.[ Read also: Understanding mass data fragmentation | Get daily insights Sign up for Network World newsletters ] Among the findings from Ivanti's survey:To read this article in full, please click here

Some IT pros say they have too much data

A new survey has found that a growing number of IT professionals have too many data sources to even count, and they are spending more and more time just wrestling that data into usable condition.Ivanti, an IT asset management firm, surveyed 400 IT professionals on their data situation and found IT faces numerous challenges when it comes to siloes, data, and implementation. The key takeaway is data overload is starting to overwhelm IT managers and data lakes are turning into data oceans.[ Read also: Understanding mass data fragmentation | Get daily insights Sign up for Network World newsletters ] Among the findings from Ivanti's survey:To read this article in full, please click here

BrandPost: The Practical Road to Intelligent Automation

Frank O. Miller, Chief Technology Officer, Europe, Middle East and Africa, Ciena Big bang OSS transformation projects are slow, expensive, and disruptive. Why not consider taking a ‘brick-by-brick’ approach that delivers value faster and sets you up for future success? asks Frank Miller, CTO, Ciena EMEA.When I’m talking with service providers, network automation is always high on their agenda. As well as dramatically reducing operational costs by automating manual processes, it can help you access bandwidth on demand, and provision new customer services in a fraction of the time it previously took. There are also major benefits in terms of discovering your network resources dynamically. An accurate view of available infrastructure enables you to more holistically plan and implement strategic initiatives that keep you ahead of the traffic demand curve.To read this article in full, please click here

BrandPost: SD-WAN is Critical for IoT

The Internet of Things (IoT) is everywhere and its use is growing fast. IoT is used by local governments to build smart cities. It’s used to build smart businesses. And, consumers are benefitting as it’s built into smart homes and smart cars. Industry analyst first estimates that over 20 billion IoT devices will be connected by 2020. That’s a 2.5x increase from the more than 8 billion connected devices in 2017*. Manufacturing companies have the highest IoT spend to date of industries while the health care market is experiencing the highest IoT growth. By 2020, 50 percent of IoT spending will be driven by manufacturing, transportation and logistics, and utilities.To read this article in full, please click here

Five Functional Facts About AWS Service Control Policies

Following on the heels of my previous post, Five Functional Facts about AWS Identity and Access Management, I wanted to dive into a separate, yet related way of enforcing access policies in AWS: Service Control Policies (SCPs).

SCPs and IAM policies look very similar–both being JSON documents with the same sort of syntax–and it would be easy to mistake one for the other. However, they are used in different contexts and for different purposes. In this post, I’ll explain the context where SCPs are used and why they are used (and even why you’d use SCPs and IAM policies together).

Read on, dear reader!

1 – SCPs scope the permissions an AWS account has

To properly describe SCPs, I need to introduce a new service: AWS Organizations. Organizations is a service that is used to bring multiple AWS accounts together under a common management structure. For example, if you wanted to enforce the use of encryption on S3 buckets across all the AWS accounts used within your company, you could do that via AWS Organizations. Additional benefits of Organizations include consolidated billing, integration with certain services such as AWS CloudTrail, and streamlined sharing of resources between accounts using Continue reading

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