March/April 2021 issue of acmqueue The March/April 2021 issue of acmqueue is out now

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January/February 2021

Escaping the Singularity:
Fail-fast Is Failing... Fast!

  Pat Helland

Changes in compute environments are placing pressure on tried-and-true distributed-systems solutions.

For more than 40 years, fail-fast has been the dominant way of achieving fault tolerance. In this approach, some mechanism is responsible for ensuring that each component is up, functioning, and responding to work. As the industry moves to leverage cloud computing, this is getting more challenging. The way we create robust solutions is under pressure as the individual components don't fail fast but instead, starts running slow, which is far worse The slow component may be healthy enough to say, "I'm still here!" but slow enough to clog up all the work. This makes fail-fast schemes vulnerable.

Distributed Computing, Distributed Development, Escaping the Singularity, Quality Assurance

Software Development in Disruptive Times

  João Varajão

Creating a software solution with fast decision capability, agile project management, and extreme low-code technology

In this project, the challenge was to "deploy software faster than the coronavirus spread." In a project with such peculiar characteristics, several factors can influence success, but some clearly stand out: top management support, agility, understanding and commitment of the project team, and the technology used. Conventional development approaches and technologies would simply not be able to meet the requirements promptly.


Kode Vicious:
Aversion to Versions

Resolving code-dependency issues

One should never hardcode a version or a path inside the code itself. Code needs to be flexible so that it can be installed anywhere and run anywhere so long as the necessary dependencies can be resolved, either at build time for statically compiled code or at runtime for interpreted code or code with dynamically linked libraries. There are current, good ways to get this right, so it's a shame that so many people continue to get it wrong.

Development, Kode Vicious

WebRTC - Realtime Communication for the Open Web Platform

  Niklas Blum, Serge Lachapelle, and Harald Alvestrand, Google

What was once a way to bring audio and video to the web has expanded into more use cases we could ever imagine.

In this time of pandemic, the world has turned to Internet-based, RTC (realtime communication) as never before. The number of RTC products has, over the past decade, exploded in large part because of cheaper high-speed network access and more powerful devices, but also because of an open, royalty-free platform called WebRTC. WebRTC is growing from enabling useful experiences to being essential in allowing billions to continue their work and education, and keep vital human contact during a pandemic. The opportunities and impact that lie ahead for WebRTC are intriguing indeed.

Web Services

Toward Confidential Cloud Computing

  Mark Russinovich, Manuel Costa, Cédric Fournet, David Chisnall, Antoine Delignat-Lavaud, Sylvan Clebsch, Kapil Vaswani, Vikas Bhatia

Extending hardware-enforced cryptographic protection to data while in use

Although largely driven by economies of scale, the development of the modern cloud also enables increased security. Large data centers provide aggregate availability, reliability, and security assurances. The operational cost of ensuring that operating systems, databases, and other services have secure configurations can be amortized among all tenants, allowing the cloud provider to employ experts who are responsible for security; this is often unfeasible for smaller businesses, where the role of systems administrator is often conflated with many others.

Distributed Computing, Privacy, Security

The SPACE of Developer Productivity

  Nicole Forsgren, Margaret-Anne Storey, Chandra Maddila, Thomas Zimmermann, Brian Houck, Jenna Butler

There's more to it than you think.

Developer productivity is about more than an individual's activity levels or the efficiency of the engineering systems relied on to ship software, and it cannot be measured by a single metric or dimension. The SPACE framework captures different dimensions of productivity, and here we demonstrate how this framework can be used to understand productivity in practice and why using it will help teams better understand developer productivity and create better measures to inform their work and teams.

Management, Workflow


November/December 2020

Drill Bits:
Offline Algorithms in Low-Frequency Trading

  Terence Kelly

Clearing Combinatorial Auctions

Expectations run high for software that makes real-world decisions, particularly when money hangs in the balance. This third episode of the Drill Bits column shows how well-designed software can effectively create wealth by optimizing gains from trade in combinatorial auctions. We'll unveil a deep connection between auctions and a classic textbook problem, we'll see that clearing an auction resembles a high-stakes mutant Tetris, we'll learn to stop worrying and love an NP-hard problem that's far from intractable in practice, and we'll contrast the deliberative business of combinatorial auctions with the near-real-time hustle of high-frequency trading. The example software that accompanies this installment of Drill Bits implements two algorithms that clear combinatorial auctions.

Code, Development, Drill Bits, Software Design

Enclaves in the Clouds

  Jatinder Singh, Jennifer Cobbe, Do Le Quoc, and Zahra Tarkhani

Legal considerations and broader implications

With organizational data practices coming under increasing scrutiny, demand is growing for mechanisms that can assist organizations in meeting their data-management obligations. TEEs (trusted execution environments) provide hardware-based mechanisms with various security properties for assisting computation and data management. TEEs are concerned with the confidentiality and integrity of data, code, and the corresponding computation. Because the main security properties come from hardware, certain protections and guarantees can be offered even if the host privileged software stack is vulnerable.


Commit to Memory:
Let's Play Global Thermonuclear Energy

  Jessie Frazelle

It's important to know where your power comes from.

For us to grow and progress as a civilization, we need more investment in providing electricity to the world through clean, safe, and efficient processes. Thermonuclear energy is a huge step forward. This article is mostly focused on the use cases around grid-scale reactors. It's hard to see a future without some sort of thermonuclear energy powering all sorts of things around us.

Commit to Memory, Hardware, Power

Best Practice: Application Frameworks

  Chris Nokleberg and Brad Hawkes

While powerful, frameworks are not for everyone.

After an overview of the central aspects of frameworks, we dive deeper into the benefits of frameworks, the tradeoffs they entail, and the most important features we recommend implementing. Then we show a practical application of frameworks at Google: how developing a microservices platform allowed Google to break up its monolithic code base, and how frameworks enabled that change.


Kode Vicious
The Non-psychopath's Guide to Managing an Open-source Project

Respect your staff, learn from others, and know when to let go.

Transitioning from one of the technical faithful to one of the hated PHBs (pointy-haired bosses), whether in the corporate or the open-source world, is truly a difficult transition. Unless you are a type who has always been meant for the C-suite it's going to take a lot of work and a lot of patience, mostly with yourself, to make this transition. Doing something "for the good of (blank)" usually means you are sublimating your own needs to the needs of others, and if you don't acknowledge that, you are going to get smacked and surprised by your own reactions to people very, very quickly.

Kode Vicious, Management, Open Source

Escaping the Singularity:
Baleen Analytics

  Pat Helland

Large-scale filtering of data provides serendipitous surprises.

Data analytics hoovers up anything it can find and we are finding patterns and insights that weren't available before, with implications for both data analytics and for messaging between services and microservices. It seems that a pretty good understanding among many different sources allows more flexibility and interconnectivity. Increasingly, flexibility dominates perfection.

Escaping the Singularity, Data

Case Study:
Always-on Time-series Database:
Keeping Up Where There's No Way to Catch Up

A discussion with Theo Schlossnagle, Justin Sheehy, and Chris McCubbin

What if you found you needed to provide for the capture of data from disconnected operations, such that updates might be made by different parties at the same time without conflicts? And what if your service called for you to receive massive volumes of data almost continuously throughout the day, such that you couldn't really afford to interrupt data ingest at any point for fear of finding yourself so far behind present state that there would be almost no way to catch up?

Case studies, Databases


September/October 2020

Everything VPN is New Again

  David Crawshaw

The 24-year-old security model has found a second wind.

The VPN (virtual private network) is 24 years old. The concept was created for a radically different Internet from the one we know today. As the Internet grew and changed, so did VPN users and applications. The VPN had an awkward adolescence in the Internet of the 2000s, interacting poorly with other widely popular abstractions. In the past decade the Internet has changed again, and this new Internet offers new uses for VPNs. The development of a radically new protocol, WireGuard, provides a technology on which to build these new VPNs.


Commit to Memory:
Battery Day

  Jessie Frazelle

A closer look at the technology that makes portable electronics possible

Tesla held its first Battery Day on September 22, 2020. The Tesla team didn't just look at one angle but all the angles: cell design, manufacturing, vehicle integration, and materials. If Tesla were to achieve 400 watt-hours per kilogram, a zero-emissions jet just might be on the horizon.

Commit to Memory, Hardware

Case Study:
Differential Privacy

The Pursuit of Protections by Default

A discussion with Miguel Guevara, Damien Desfontaines, Jim Waldo, and Terry Coatta

First formalized in 2006, differential privacy is an approach based on a mathematically rigorous definition of privacy that allows formalization and proof of the guarantees against re-identification offered by a system. While differential privacy has been accepted by theorists for some time, its implementation has turned out to be subtle and tricky, with practical applications only now starting to become available. To date, differential privacy has been adopted by the U.S. Census Bureau, along with a number of technology companies, but what this means and how these organizations have implemented their systems remains a mystery to many.

Case studies, Privacy and Rights

Drill Bits:
Decentralized Computing

  Terence Kelly

Feeding all relevant inputs to a central solver is the obvious way to tackle a problem, but it's not always the only way. Decentralized methods that make do with only local communication and local computation are sometimes the best way. This episode of Drill Bits reviews an elegant protocol for self-organizing wireless networks that can also solve a seemingly impossible social networking problem. The protocol preserves privacy among participants and is so simple that it can be implemented with pencil, paper, and postcards. Example software implements both the decentralized protocol and a centralized solver.

Code, Development, Distributed Computing, Drill Bits, Software Design

Kode Vicious
Kabin Fever

KV's guidelines for KFH (koding from home)

Let me invite you to my next Zoom meeting on how to host Zoom meetings! As a devotee of mobile computing and remote work from my earliest days at university, I have, over time, developed a number of useful habits for maintaining a good and productive working rhythm, and I've found that many of these apply well to those of you who are newly working from home.

Business and Management, Development, Kode Vicious

Everything Sysadmin:
The Time I Stole $10,000 from Bell Labs

  Thomas A. Limoncelli

Or why DevOps encourages us to celebrate outages.

If IT workers fear they will be punished for outages, they will adopt behavior that leads to even larger outages. Instead, we should celebrate our outages: Document them blamelessly, discuss what we've learned from them openly, and spread that knowledge generously. An outage is not an expense. It is an investment in the people who have learned from it. We can maximize that investment through management practices that maximize learning for those involved and by spreading that knowledge across the organization. Managed correctly, every outage makes the organization smarter. In short, the goal should be to create a learning culture—one that seeks to make only new mistakes.

Business and Management, Everything Sysadmin, Failure and Recovery

A Second Conversation with Werner Vogels

The Amazon CTO sits with Tom Killalea to discuss designing for evolution at scale.

When I joined Amazon in 1998, the company had a single US-based website selling only books and running a monolithic C application on five servers, a handful of Berkeley DBs for key/value data, and a relational database. That database was called "ACB" which stood for "Amazon.Com Books," a name that failed to reflect the range of our ambition. In 2006 acmqueue published a conversation between Jim Gray and Werner Vogels, Amazon's CTO, in which Werner explained that Amazon should be viewed not just as an online bookstore but as a technology company. In the intervening 14 years, Amazon's distributed systems, and the patterns used to build and operate them, have grown in influence. In this follow-up conversation, Werner and I pay particular attention to the lessons to be learned from the evolution of a single distributed system, S3, which was publicly launched close to the time of that 2006 conversation.

Interviews, System Evolution, Web Services


July/August 2020

The Die is Cast

  Edlyn V. Levine, Ph.D.

Hardware Security is Not Assured

The future of hardware security will evolve with hardware. As packaging advances and focus moves to beyond Moore's law technologies, hardware security experts will need to keep ahead of changing security paradigms, including system and process vulnerabilities. Research focused on quantum hacking is emblematic of the translation of principles of security on the physical attack plane for emerging communications and computing technologies. Perhaps the commercial market will evolve such that the GAO will run a study on compromised quantum technologies in the not-too-distant future.

Hardware, Security

Commit to Memory:
Out-of-this-World Additive Manufacturing

  Jessie Frazelle

From thingamabobs to rockets, 3D printing takes many forms.

Popular culture uses the term '3D printing' as a synonym for additive manufacturing processes. In 2010, the ASTM (American Society for Testing and Materials) came up with a set of standards to classify additive manufacturing processes into seven categories. Each process uses different materials and machine technology, which affects the use cases and applications, as well as the economics. I went down a rabbit hole researching the various processes in my hunt to buy the best 3D printer. In this article I will share what I learned about each process, as well as some of the more interesting use cases I found along the way.

Commit to Memory, Hardware,

The Identity in Everyone's Pocket

  Phil Vachon

Keeping users secure through their smartphones

This article is meant to leave you with ideas about how to bring a hardware-backed and biometrics-based concept of user identity into your ecosystem. The goal is simple: Make it as hard as possible for attackers to steal credentials and use them at their leisure. Let's even make it difficult for users to clone their own credentials to share with other users. In addition to this protection, let's ensure that adding extra factors such as biometric authentication provides a stronger assurance of who the user is. Bringing keys and other secrets closer and closer to something that is physically attached to the user provides a stronger assurance of the identity of the user who just authenticated to the device.

Messaging, Privacy and Rights, Security

Kode Vicious
Removing Kode

Dead functions and dead features

Removing dead code from systems is one of KV's favorite koding pastimes because there is nothing quite like that feeling you get when you get rid of something you know wasn't being used. Code removal is like cleaning house, only sometimes you clean house with a flame thrower, which, honestly, is very satisfying. Since you're using a version-control system (you had better be using a VCS!), it's very easy to remove code without worry. If you ever need the code you removed, you can retrieve it from the VCS at will.

Development, Kode Vicious

Security Analysis of SMS as a Second Factor of Authentication

  Roger Piqueras Jover

The challenges of multifactor authentication based on SMS, including cellular security deficiencies, SS7 exploits, and SIM swapping

Despite their popularity and ease of use, SMS-based authentication tokens are arguably one of the least secure forms of two-factor authentication. This does not imply, however, that it is an invalid method for securing an online account.

The current security landscape is very different from that of two decades ago. Regardless of the critical nature of an online account or the individual who owns it, using a second form of authentication should always be the default option, regardless of the method chosen. In the wake of a large number of leaks and other intrusions, there are many username and password combinations out there in the wrong hands that make password spraying attacks cheap and easy to accomplish.

Messaging, Security

Drill Bits:
Efficient Graph Search

  Terence Kelly

Stop when done.

Welcome to Drill Bits, a new column about programming. This inaugural episode shows how graph search algorithms can avoid unnecessary work. A simple modification to classic breadth-first search improves the lower bound on its running time: Whereas classic BFS always requires time proportional to the number of vertices plus the number of edges, the improved "Efficient BFS" sometimes runs in time proportional to the number of vertices alone. Both asymptotic analysis and experiments show that Efficient BFS can be much faster than classic BFS. All software used in the experiments is available for download, and suggestions for further explorations are provided.

Code, Development, Drill Bits, Software Design Software Design


May/June 2020

Commit to Memory:
The Life of a Data Byte

  Jessie Frazelle

Be kind and rewind.

This article travels in time through various storage media, diving into how data has been stored throughout history. We start off with the state of the art in storage media in 1951 and conclude after looking at the future of storage technology. Storage has changed a lot over time; from paper tape to metal tape, magnetic tape, rope memory, spinning disks, optical disks, flash, and others. Progress has led to faster, smaller, and more performant devices for storing data.

Commit to Memory, Computer Architecture Data and Databases

Scrum Essentials Cards

  Jeff Sutherland, Ivar Jacobson, and Brian Kerr

Experiences of Scrum Teams Improving with Essence

This article presents a series of examples and case studies on how people have used the Scrum Essentials cards to benefit their teams and improve how they work.


Everything Sysadmin:
Five Nonobvious Remote Work Techniques

  Thomas A. Limoncelli

Emulating the efficiency of in-person conversations

The physical world has social conventions around conversations and communication that we use without even thinking. As we move to a remote-work world, we have to be more intentional to create such conventions. Developing these social norms is an ongoing commitment that outlasts initial technical details of VPN and desktop videoconference software configuration.

Companies that previously forbade remote work can no longer deny its benefits. Once the pandemic-related lockdowns are over, many people will continue working remotely. Those who return to the office will need to work in ways that are compatible with their remotely working associates.

Business and Management, Everything Sysadmin

Data on the Outside vs. Data on the Inside

  Pat Helland

Data kept outside SQL has different characteristics from data kept inside.

This article describes the impact of services and trust on the treatment of data. It introduces the notions of inside data as distinct from outside data. The article then examines the notion of reference data and its usage patterns in facilitating the interoperation of services. Finally, JSON and SQL are seen as representations of data, and their strengths are compared and contrasted. It is common practice today to use JSON to represent data on the outside and SQL to store the data on the inside.

Data and Databases

Kode Vicious
Sanity vs. Invisible Markings

Tabs vs. spaces

Making it easy for tools to understand the structure of software is one of the keys to having tools that help programmers prepare proper programs for computers. Since the earliest days of software development, programmers have tried to build tools that show them where there might be issues in the program text. Code editors have added colorization, syntax highlighting, folding, and a host of other features in a desperate, and some might say fruitless, attempt to improve the productivity of programmers.

Kode Vicious

The History, Status, and Future of FPGAs

  Oskar Mencer, et al.

Hitting a nerve with field-programmable gate arrays

FPGAs (field-programmable gate arrays) have been hitting a nerve in the ASIC community since their inception. In the mid-1980s, Ross Freeman and his colleagues bought the technology from Zilog and started Xilinx, targeting the ASIC emulation and education markets. In parallel, Altera was founded with similar technology at its core. This article is a summary of a three-hour discussion at Stanford University in September 2019 among the authors. It has been written with combined experiences at and with organizations such as Zilog, Altera, Xilinx, Achronix, Intel, IBM, Stanford, MIT, Berkeley, University of Wisconsin, the Technion, Fairchild, Bell Labs, Bigstream, Google, DIGITAL (DEC), SUN, Nokia, SRI, Hitachi, Silicom, Maxeler Technologies, VMware, Xerox PARC, Cisco, and many others.

Computer Architecture, Processors



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