Blog posts

Drilling down on Rust Performance Bottlenecks with tokio-tracing and texray

10 minute read

Published: April 28, 2025

When a Rust program feels sluggish, adding instrumentation can shine a light on where the time is going. In this post, we’ll walk through a guided journey of using Tokio’s tracing framework and the tracing-texray tool to drill into performance issues. We assume you’re familiar with the basics of tokio-tracing (if not, see the Tokio tracing introduction for spans and events fundamentals). Our journey will start with a simple sequential task, then ramp up to parallel execution and illustrate how to maintain insight at each step.

Byzantine-Consistent Broadcast- A Promising Yet Challenging Frontier in Digital Asset Transfers

7 minute read

Published: March 31, 2025

Digital asset transfer systems are at a crossroads. An idea that first captured attention between 2020 and 2022—Byzantine Consistent Broadcast (BCB)—is now experiencing a revival with projects like Pod and Delta. In this post, we to show that while BCB can unlock incredible performance through parallel state execution, it also introduces important challenges, especially around expressivity and the scalability of reads. The goal is to explain why this approach is both exciting and demanding.

PSA: maven central and sonatype are slow

less than 1 minute read

Published: July 27, 2017

Most of the public maven repositories for downloading java artifacts (notably maven-central, and sonatype) are slow. Besides, build tools do not have a perfect track record of resolving dependencies from these repositories in an efficient manner.

A June 2016 roundup of distributed Deep Learning projects on Apache Spark

1 minute read

Published: June 28, 2016

Here’s a quick roundup of distributed deep learning efforts running on Apache Spark. This will only list active(-ish) projects rather than academic experiments (of which there are too many to list) There’s roughly two approaches:

May 2016 time series storage roundup

1 minute read

Published: May 09, 2016

A recent slew of blogs and articles have been shedding new insight on time series storage. I thought I’d list some of the zeitgeist.

Another update on streaming work

2 minute read

Published: July 15, 2015

This is an update on my previous post about work by Typesafe to add resiliency to Spark Streaming.

A quick update on Spark Streaming work

3 minute read

Published: July 10, 2015

Since I was asked a few times here at Scala Days, I thought I’d write an update on how some of our work on making Spark Streaming more resilient is going. Naturally, all of this is open-source, otherwise I wouldn’t be writing this.

Diving In The Deep End of The Big Data Pool: Talk Abstract

1 minute read

Published: November 19, 2014

This is the Abstract for my Ignite talk at the Strata+Hadoop Barcelona conference, on Wed Nov 19th, 2014 (at CCIB, room 116, 5:30PM). I haven’t found any place where O’Reilly would publish that abstract, and I thought some people would want a peek at what I’d talk about.

Installing Xen on an Apple iMac

3 minute read

Published: November 13, 2014

Introduction

A question about the Option Monad Transformer

8 minute read

Published: July 14, 2014

I’ve recently heard the following suprisingly general question:

Look, Ma, no queues!

4 minute read

Published: October 23, 2013

A very classic, if a bit overrated exercise, is to print a tree in width-first order. Also called level-order, it means you print your binary tree row-by-row, with the nodes of depth d, leftmost first, before the nodes of depth d+1.

How a Ramdisk saved my life

5 minute read

Published: February 15, 2013

… or how the devil finds work for idle hands.

Every freshman CS question in ±80 lines of Scala

14 minute read

Published: January 12, 2012

This post is about writing a single program that returns the stream representing any recursive sequence of order $k$, which $i$th term a[i] = f(a[i-1], a[i-2], ... a[i-k]), for all $k$, in Scala. It explains things very slowly: If the meaning of the previous sentence is already 100% clear to you, you can easily skip the next 2 paragraphs.

Certifying RSA correct for breakfast

7 minute read

Published: August 27, 2011

Reasoning on the correctness of the RSA cryptosystem is much easier with a little bit of algebra: this is a perfect example of a case where the ``practical’’ applications of proof assistants can be helped with libraries dealing with abstract algebra, including SSReflect. The proof we are going to build in the present post is based on a stock SSReflect version 1.3pl1, and is available on github. It can be compared with the RSA contribution to Coq, made on the basis of the standard library (note this is not a code golf, but rather a tentative to demonstrate that a big mathematical library helps).

How do you make a recursive merge sort more efficient in Python?

5 minute read

Published: August 17, 2011

This is re-worked from an excerpt of an answer of mine (¹) to an SO question that made me discover some interesting things about Python : turns out it’s not easy to make recursion faster by doing tail call elimination, even by hand. (²)

Ligtweight profiling for your Coq hacks

3 minute read

Published: August 11, 2011

Let’s suppose we want to hack a few functions in the Coq compiler. The classic situation is that we have the base implementation of our function as it stands, and an optimized version for which we want to check it really improves things.