jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

gaearon

function mapValues(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    result[key] = fn(obj[key], key);
    return result;
  }, {});
}

function pick(obj, fn) {
  return Object.keys(obj).reduce((result, key) => {
    if (fn(obj[key])) {

bvaughn

React recently introduced an experimental profiler API. This page gives instructions on how to use this API in a production release of your app.

Table of Contents

• Profiling in production
  • Create React App
  • Webpack 4

Profiling in production

React DOM automatically supports profiling in development mode for v16.5+, but since profiling adds some small additional overhead it is opt-in for production mode. This gist explains how to opt-in.

WesleyAC

#!/usr/bin/env bash

cd $(dirname $0)

docker run --rm -it -v "$(pwd)":/home/rust/src -v cargo-git:/home/rust/.cargo/git -v cargo-registry:/home/rust/.cargo/registry -v "$(pwd)/target/":/home/rust/src/target ekidd/rust-musl-builder:nightly-2021-01-01 sudo chown -R rust:rust /home/rust/.cargo/git /home/rust/.cargo/registry /home/rust/src/target

docker run --rm -it -v "$(pwd)":/home/rust/src -v cargo-git:/home/rust/.cargo/git -v cargo-registry:/home/rust/.cargo/registry -v "$(pwd)/target/":/home/rust/src/target ekidd/rust-musl-builder:nightly-2021-01-01 cargo build --release

killercup

/*
 * I add this to html files generated with pandoc.
 */

html {
  font-size: 100%;
  overflow-y: scroll;
  -webkit-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
}

MatthewJamesBoyle

FROM golang:1.21.0-bullseye as builder

COPY . /workdir
WORKDIR /workdir

ENV CGO_CPPFLAGS="-D_FORTIFY_SOURCE=2 -fstack-protector-all"
ENV GOFLAGS="-buildmode=pie"

RUN go build -ldflags "-s -w" -trimpath ./cmd/app

isaacs

echo 'export PATH=$HOME/local/bin:$PATH' >> ~/.bashrc
. ~/.bashrc
mkdir ~/local
mkdir ~/node-latest-install
cd ~/node-latest-install
curl http://nodejs.org/dist/node-latest.tar.gz | tar xz --strip-components=1
./configure --prefix=~/local
make install # ok, fine, this step probably takes more than 30 seconds...
curl https://www.npmjs.org/install.sh | sh

joost-de-vries

Akka and Kotlin coroutines: ♡

I've experimented with Kotlin and coroutines in programming Akka. And I must say, I really like the combination so far.
But before I go into it some brief preliminaries for those who don't know Akka and actors.

Actors and Akka

Actors are a programming model that fits cloud native architectures particularly well. Being highly available and scaling horizontally. All while embracing the realities of multiple servers collaborating, server instances coming and going and the network having hickups.

On the JVM Akka is the prominent actor framework. It's been around for a while now and as a result it's highly reliable, well thought out and offers a wide programming eco system. My own interest in Akka is because of its suitability for software systems that can only be built with business events as a key construct and thinking model. And then of course materialized views, CQRS and near real-time data streams play a big role in constructing those systems.

rsms

[Unit]
Description = Foo HTTP server
Requires    = foo.socket
After       = multi-user.target

[Service]
User             = www-data
Group            = www-data
WorkingDirectory = /var/foo
ExecStart        = /var/foo/bin/foo-server