luminousmen

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

luminousmen

.PHONY: clean-pyc clean-build docs clean
define BROWSER_PYSCRIPT
import os, webbrowser, sys
try:
	from urllib import pathname2url
except:
	from urllib.request import pathname2url

webbrowser.open("file://" + pathname2url(os.path.abspath(sys.argv[1])))
endef

luminousmen

# install
mkdir ~/airflow
cd ~/airflow
pip install airflow
# Have a look here if you need additional packages: https://airflow.incubator.apache.org/installation.html

# setup mysql backend as given here. The default SQLite is not adequate for some workloads.
# http://site.clairvoyantsoft.com/installing-and-configuring-apache-airflow/
 
# start services

luminousmen

// Just before switching jobs:
// Add one of these.
// Preferably into the same commit where you do a large merge.
//
// This started as a tweet with a joke of "C++ pro-tip: #define private public",
// and then it quickly escalated into more and more evil suggestions.
// I've tried to capture interesting suggestions here.
//
// Contributors: @r2d2rigo, @joeldevahl, @msinilo, @_Humus_,
// @YuriyODonnell, @rygorous, @cmuratori, @mike_acton, @grumpygiant,