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?

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

webframp

Probably one of the easiest things you'll ever do with gpg

Install Keybase: https://keybase.io/download and Ensure the keybase cli is in your PATH

First get the public key

keybase pgp export | gpg --import

Next get the private key

staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

henrik

tmux cheatsheet

As configured in my dotfiles.

start new:

tmux

start new with session name:

IanColdwater

Mute these words in your settings here: https://twitter.com/settings/muted_keywords

ActivityTweet
generic_activity_highlights
generic_activity_momentsbreaking
RankedOrganicTweet
suggest_activity
suggest_activity_feed
suggest_activity_highlights
suggest_activity_tweet

adeekshith

# <type>: (If applied, this commit will...) <subject> (Max 50 char)
# |<----  Using a Maximum Of 50 Characters  ---->|


# Explain why this change is being made
# |<----   Try To Limit Each Line to a Maximum Of 72 Characters   ---->|

# Provide links or keys to any relevant tickets, articles or other resources
# Example: Github issue #23

jnschulze

#!/bin/bash

# Size at the end is * 2048 where 2048 = 1 MB, so 1572864 = 768 MB
#DISK=`/usr/bin/hdiutil attach -nobrowse -nomount ram://1572864`
DISK=`/usr/bin/hdiutil attach -nobrowse -nomount ram://2097152`

/usr/sbin/diskutil erasevolume HFS+ "RamDiskCache" $DISK

CACHEDIR="/Volumes/RamDiskCache/$USER"

mlafeldt

First of all, install Homebrew itself.

As the tap is a private Git repo, you need to generate a GitHub token with repo scope and then add this token to your ~/.netrc file like this:

machine github.com
  login <your GitHub user>
  password <your GitHub token>

jboner

# How Akka maps to EAI Patterns

Might be up for debate or just plain wrong. Just some notes I scribbled down some time ago. 

-----------------------------------------------------------------------------------------------------------------
EAI PATTERN                     AKKA PATTERN                  REFERENCE
-----------------------------------------------------------------------------------------------------------------
Point to Point Channel          Regular Actor Communication   http://www.eaipatterns.com/PointToPointChannel.html
Event-Driven Consumer           Regular Actor Receive         http://www.eaipatterns.com/EventDrivenConsumer.html
Message Selector                Actor with Stash              http://www.eaipatterns.com/MessageSelector.html