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Chris Wiltz

281 articles by Chris Wiltz.

SRE & Ops — How the Cinder JIT’s function inliner helps us optimize Instagram

How the Cinder JIT’s function inliner helps us optimize Instagram

Since Instagram runs one of the world’s largest deployments of the Django web framework, we have natural interest in finding ways to optimize Python so we can speed up our production application. As part of this effort, we’ve recently open-sourced Cinder, our Python runtime that is a fork of CPython. Cinder includes optimizations like immortal […]

CWChris Wiltz·May 2, 2022SRE & Ops
SRE & Ops — How Meta enables de-identified authentication at scale

How Meta enables de-identified authentication at scale

Data minimization — collecting the minimum amount of data required to support our services — is one of our core principles at Meta as we continue developing new privacy-enhancing technologies (PETs). We are constantly seeking ways to improve privacy and protect user data on our family of products. Previously, we’ve approached data minimization by exploring […]

CWChris Wiltz·March 30, 2022SRE & Ops
SRE & Ops — Detecting silent errors in the wild: Combining two novel approaches to quickly detect silent data corruptions at scale

Detecting silent errors in the wild: Combining two novel approaches to quickly detect silent data corruptions at scale

Silent data corruptions (SDCs), data errors that go undetected by the larger system, are a widespread problem for large-scale infrastructure systems. Left undetected, these types of corruptions can cause data loss and propagate across the stack and manifest as application-level problems. Silent data corruptions (SDC) in hardware impact computational integrity for large-scale applications. Sources

CWChris Wiltz·March 17, 2022SRE & Ops
SRE & Ops — VESPA: Static profiling for binary optimization

VESPA: Static profiling for binary optimization

What the research is: Recent research has demonstrated that binary optimization is important for achieving peak performance for various applications. For instance, the state-of-the-art BOLT binary optimizer developed at Meta, which is part of the LLVM Compiler Project, significantly improves the performance of highly optimized binaries produced using compilers’ most aggressive optimizations, such

CWChris Wiltz·March 15, 2022SRE & Ops
Frontend — An open source compositional deadlock detector for Android Java

An open source compositional deadlock detector for Android Java

What the research is: We’ve developed a new static analyzer that catches deadlocks in Java code for Android without ever running the code. What distinguishes our analyzer from past research is its ability to analyze revisions in codebases with hundreds of millions of lines of code. We have deployed our analyzer in Meta’s continuous integration […]

CWChris Wiltz·March 8, 2022Frontend
SRE & Ops — Augmenting Flexible Paxos in LogDevice to improve read availability

Augmenting Flexible Paxos in LogDevice to improve read availability

We’ve improved read availability in LogDevice, Meta’s scalable distributed log storage system, by removing a fundamental trade-off in Flexible Paxos, the algorithm used to gain consensus among our distributed systems. At Meta’s scale, systems need to be reliable, even in the face of organic failures like power loss events, or when systems are undergoing hardware […]

CWChris Wiltz·March 7, 2022SRE & Ops
SRE & Ops — Power Loss Siren: Making Meta resilient to power loss events

Power Loss Siren: Making Meta resilient to power loss events

There are thousands of distributed services running on millions of servers in Meta’s data centers. Part of ensuring the reliability of those services means making them resilient to power loss events as our data center fleet grows. To help increase resiliency, we built the Power Loss Siren (PLS) — a rack level, low latency, distributed […]

CWChris Wiltz·December 16, 2021SRE & Ops
SRE & Ops — OCP Summit 2021: Open networking hardware lays the groundwork for the metaverse

OCP Summit 2021: Open networking hardware lays the groundwork for the metaverse

Open infrastructure technologies and networking hardware will play an important role as we build new technologies for the metaverse, where billions of people will someday come together in virtual spaces. As we head toward the next major computing platform with a continued spirit of embracing openness and disaggregation, we’re announcing two new milestones for our […]

CWChris Wiltz·November 9, 2021SRE & Ops
SRE & Ops — Kangaroo: A new flash cache optimized for tiny objects

Kangaroo: A new flash cache optimized for tiny objects

What the research is: Kangaroo is a new flash cache that enables more efficient caching of tiny objects (objects that are ~100 bytes or less) and overcomes the challenges presented by existing flash cache designs. Since Kangaroo is implemented within CacheLib, Facebook’s open source caching engine, developers can use Kangaroo through CacheLib’s API to build […]

CWChris Wiltz·October 26, 2021SRE & Ops
Networking — RTMP Go Away: Lossless reconnections for live streaming

RTMP Go Away: Lossless reconnections for live streaming

What it is: Real Time Messaging Protocol (RTMP) is a popular media streaming protocol that uses Transmission Control Protocol (TCP) persistent connections. When a connection between a live-streaming client and the platform is interrupted, data from the live event is lost until the client can reconnect to a new server. RTMP Go Away is a […]

CWChris Wiltz·October 19, 2021Networking
Frontend — Open-sourcing Mariana Trench: Analyzing Android and Java app security in depth

Open-sourcing Mariana Trench: Analyzing Android and Java app security in depth

We’re sharing details about Mariana Trench (MT), a tool we use to spot and prevent security and privacy bugs in Android and Java applications. As part of our effort to help scale security through building automation, we recently open-sourced MT to support security engineers at Facebook and across the industry. This post is the third […]

CWChris Wiltz·September 29, 2021Frontend
Security — How WhatsApp is enabling end-to-end encrypted backups

How WhatsApp is enabling end-to-end encrypted backups

For years, in order to safeguard the privacy of people’s messages, WhatsApp has provided end-to-end encryption by default ​​so messages can be seen only by the sender and recipient, and no one in between. Now, we’re planning to give people the option to protect their WhatsApp backups using end-to-end encryption as well. People can already […]

CWChris Wiltz·September 10, 2021Security
SRE & Ops — RAMP-TAO: Layering atomic transactions on Facebook’s online graph store

RAMP-TAO: Layering atomic transactions on Facebook’s online graph store

What the research is: RAMP-TAO is a new protocol that improves the developer experience on TAO, Facebook’s online social graph store, by providing stronger transactional guarantees. It is the first protocol to provide transactional semantics over an eventually consistent massive-scale data store while still preserving the system’s overall reliability and performance. RAMP-TAO enables an intuitive

CWChris Wiltz·August 18, 2021SRE & Ops
SRE & Ops — Migrating Facebook to MySQL 8.0

Migrating Facebook to MySQL 8.0

MySQL, an open source database developed by Oracle, powers some of Facebook’s most important workloads. We actively develop new features in MySQL to support our evolving requirements. These features change many different areas of MySQL, including client connectors, storage engine, optimizer, and replication. Each new major version of MySQL requires significant time and effort to […]

CWChris Wiltz·July 22, 2021SRE & Ops
AI & ML — Fully Sharded Data Parallel: faster AI training with fewer GPUs

Fully Sharded Data Parallel: faster AI training with fewer GPUs

Training AI models at a large scale isn’t easy. Aside from the need for large amounts of computing power and resources, there is also considerable engineering complexity behind training very large models. At Facebook AI Research (FAIR) Engineering, we have been working on building tools and infrastructure to make training large AI models easier. Our […]

CWChris Wiltz·July 15, 2021AI & ML
Security — How WhatsApp enables multi-device capability

How WhatsApp enables multi-device capability

For years, people have been asking us to create a true multi-device experience that allows people to use WhatsApp on other devices without requiring a smartphone connection. Today, we’re announcing the rollout of a limited public beta test for WhatsApp’s updated multi-device capability. With this new capability, you can now use WhatsApp on your phone […]

CWChris Wiltz·July 14, 2021Security
SRE & Ops — Ribbon filter: Practically smaller than Bloom and Xor

Ribbon filter: Practically smaller than Bloom and Xor

What the research is: The Ribbon filter is a new data structure that is more space-efficient than the popular Bloom filters that are widely used for optimizing data retrieval. One of the ways that Bloom, and now Ribbon, filters solve real engineering problems is by providing smooth configurability unmatched by other filters. Bloom filters work […]

CWChris Wiltz·July 9, 2021SRE & Ops
SRE & Ops — Asicmon: A platform agnostic observability system for AI accelerators

Asicmon: A platform agnostic observability system for AI accelerators

Accelerators are special-purpose hardware devices optimized for specific applications, like AI prediction and video encoding. And Application-specific hardware platforms play an important role in meeting the growing latency and compute demands of workloads like deep learning, content understanding, and video encoding. At Facebook, the inevitable rise in use of accelerators in our data centers has

CWChris Wiltz·June 28, 2021SRE & Ops
Networking — Driving towards an open internet ecosystem to help tackle the digital divide

Driving towards an open internet ecosystem to help tackle the digital divide

Connectivity is an integral part of Facebook’s mission to bring people closer together, and the COVID-19 pandemic has only heightened the demand for critical internet access. According to the latest edition of our Inclusive Internet Index, nearly 70 percent of people around the world believe that increased internet usage in all aspects of their lives […]

CWChris Wiltz·June 28, 2021Networking
SRE & Ops — How Facebook deals with PCIe faults to keep our data centers running reliably

How Facebook deals with PCIe faults to keep our data centers running reliably

Peripheral component interconnect express (PCIe) hardware continues to push the boundaries of computing thanks to advances in transfer speeds, the number of available lanes for simultaneous data delivery, and a comparatively small footprint on motherboards. Today, PCIe connectivity-based hardware delivers faster data transfers and is one of the de facto methods to connect components to […] Read Mo

CWChris Wiltz·June 2, 2021SRE & Ops
SRE & Ops — A brief history of Rust at Facebook

A brief history of Rust at Facebook

Facebook is embracing Rust, one of the most loved and fastest-growing programming languages available today. In addition to bringing new talent to its Rust team, Facebook has announced that it is officially joining the nonprofit Rust Foundation. Alongside fellow members including Mozilla (the creators of Rust), AWS, Microsoft, and Google, Facebook will be working to […]

CWChris Wiltz·April 29, 2021SRE & Ops
SRE & Ops — DIT — enabling de-identified data collection on WhatsApp

DIT — enabling de-identified data collection on WhatsApp

At WhatsApp, privacy is our DNA. That’s why we rolled out end-to-end encryption in 2016 — so that when messages are end-to-end encrypted, only you and your intended recipients can see the messages you send. But securing messages and calls is just one part of how we minimize the information we collect in the process […]

CWChris Wiltz·April 16, 2021SRE & Ops
AI & ML — How Facebook encodes your videos

How Facebook encodes your videos

People upload hundreds of millions of videos to Facebook every day. Making sure every video is delivered at the best quality — with the highest resolution and as little buffering as possible — means optimizing not only when and how our video codecs compress and decompress videos for viewing, but also which codecs are used […]

CWChris Wiltz·April 5, 2021AI & ML
Networking — Cutting Threads’ send latency in half

Cutting Threads’ send latency in half

In 2019, Instagram launched a new app for direct messaging called Threads. We built media sends in Threads using a lot of the existing infrastructure at Instagram. Many of these components do not focus on the send latency. For this post, we’ll define “send latency” as the time it takes from when the user starts a […]

CWChris Wiltz·March 22, 2021Networking
SRE & Ops — FOQS: Scaling a distributed priority queue

FOQS: Scaling a distributed priority queue

We will be hosting a talk about our work on Scaling a Distributed Priority Queue during our virtual Systems @Scale event at 11 am PT on Wednesday, February 24, followed by a live Q&A session. Please submit any questions to [email protected] before the event. The entire Facebook ecosystem is powered by thousands of distributed systems […]

CWChris Wiltz·February 22, 2021SRE & Ops
AI & ML — On the value of diversified recommendations

On the value of diversified recommendations

One of the biggest questions faced by the recommendation systems community is whether recommendation systems should be solely evaluated by their predictive accuracy, or also focus on other factors such as preference broadening. In order to appreciate the importance of this question, let us look at a couple of simulated scenarios in a dynamic setting. User […]

CWChris Wiltz·December 17, 2020AI & ML
SRE & Ops — How Facebook keeps its large-scale infrastructure hardware up and running

How Facebook keeps its large-scale infrastructure hardware up and running

Facebook’s services rely on fleets of servers in data centers all over the globe — all running applications and delivering the performance our services need. This is why we need to make sure our server hardware is reliable and that we can manage server hardware failures at our scale with as little disruption to our […]

CWChris Wiltz·December 9, 2020SRE & Ops
Networking — SuperCell: Reaching new heights for wider connectivity

SuperCell: Reaching new heights for wider connectivity

As part of our efforts to help expand connectivity around the world, Facebook Connectivity has been prototyping SuperCell, a wide-area coverage solution for increasing mobile connectivity in rural communities. Now, after working with telecom industry partners to conduct several trials and data analyses, we’re ready to share what we’ve learned. Rather than produce this solution […]

CWChris Wiltz·December 3, 2020Networking
Frontend — How Facebook is bringing QUIC to billions

How Facebook is bringing QUIC to billions

We are replacing the de facto protocol the internet has used for decades with QUIC, the latest and most radical step we’ve taken to optimize our network protocols to create a better experience for people on our services. Today, more than 75 percent of our internet traffic uses QUIC and HTTP/3 (we refer to QUIC […]

CWChris Wiltz·October 21, 2020Frontend
SRE & Ops — Introducing resctl-demo: Better resource control with simulation

Introducing resctl-demo: Better resource control with simulation

What it is: We all want our workloads to run on our machines as efficiently as possible. With the Facebook resource control demo (resctl-demo), developers can simulate system resource conflicts and test ways to resolve them. It’s like going on a guided tour through a system’s resource control, complete with live demos and detailed explanations. […]

CWChris Wiltz·October 14, 2020SRE & Ops
SRE & Ops — Fault tolerance through optimal workload placement

Fault tolerance through optimal workload placement

As our infrastructure has expanded, we have seen an exponential growth in failures that affect a subset of capacity in a data center. These may stem from software or firmware errors, or issues in the mechanical or electrical equipment in the data center. As our data center footprint grows, so does the frequency of such […]

CWChris Wiltz·September 8, 2020SRE & Ops
SRE & Ops — Scaling services with Shard Manager

Scaling services with Shard Manager

Over the years, as we’ve expanded in scale and functionalities, Facebook has evolved from a basic web server architecture into a complex one with thousands of services working behind the scenes. It’s no trivial task to scale the wide range of back-end services needed for Facebook’s products. And we found that many of our teams […]

CWChris Wiltz·August 24, 2020SRE & Ops
SRE & Ops — Retrie: Haskell refactoring made easy

Retrie: Haskell refactoring made easy

What’s new: We’ve open-sourced Retrie, a code refactoring tool for Haskell that makes codemodding faster, easier, and safer. Using Retrie, developers can efficiently rewrite large codebases (exceeding 1 million lines), express rewrites as equations in Haskell syntax instead of regular expressions, and avoid large classes of codemodding errors. Retrie’s features include the ability to rewrite […] R

CWChris Wiltz·July 6, 2020SRE & Ops