Proton feisuzhu

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

Linux Backup Solutions

I've been looking for the best Linux backup system, and also reading lots of HN comments.

Instead of putting pros and cons of every backup system I'll just list some deal-breakers which would disqualify them.

Also I would like that you, the HN community, would add more deal breakers for these or other backup systems if you know some more and at the same time, if you have data to disprove some of the deal-breakers listed here (benchmarks, info about something being true for older releases but is fixed on newer releases), please share it so that I can edit this list accordingly.

Amanda (comments by sammcj)

It has a lot of management overhead and that's a problem if you don't have time for a full time backup administrator.

	"""
	A really stupid python template language inspired by coffeekup, markaby.
	Do not use this code, it will ruin your day. A byproduct of insomnia.

	TL;DR
	-----

	This module defines a template language that allows us to do:

	d = Doc()

	server {
	listen 8080 default_server deferred;

	charset utf-8;
	access_log /var/log/nginx/graphite.access.log;
	error_log /var/log/nginx/graphite.error.log;

	root /opt/graphite/webapp;

	location /static/admin/ {

	# Raw transaction API example work-through
	# Send coins to a 2-of-3 multisig, then spend them.
	#
	# For this example, I'm using these three keypairs (public/private)
	# 0491bba2510912a5bd37da1fb5b1673010e43d2c6d812c514e91bfa9f2eb129e1c183329db55bd868e209aac2fbc02cb33d98fe74bf23f0c235d6126b1d8334f86 / 5JaTXbAUmfPYZFRwrYaALK48fN6sFJp4rHqq2QSXs8ucfpE4yQU
	# 04865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac09ef122b1a986818a7cb624532f062c1d1f8722084861c5c3291ccffef4ec6874 / 5Jb7fCeh1Wtm4yBBg3q3XbT6B525i17kVhy3vMC9AqfR6FH2qGk
	# 048d2455d2403e08708fc1f556002f1b6cd83f992d085097f9974ab08a28838f07896fbab08f39495e15fa6fad6edbfb1e754e35fa1c7844c41f322a1863d46213 / 5JFjmGo5Fww9p8gvx48qBYDJNAzR9pmH5S389axMtDyPT8ddqmw

	# First: combine the three keys into a multisig address:
	./bitcoind createmultisig 2 '["0491bba2510912a5bd37da1fb5b1673010e43d2c6d812c514e91bfa9f2eb129e1c183329db55bd868e209aac2fbc02cb33d98fe74bf23f0c235d6126b1d8334f86","04865c40293a680cb9c020e7b1e106d8c1916d3cef99aa431a56d253e69256dac09ef122b1a9

	from sqlalchemy import (create_engine, event,
	Column, Integer,
	ForeignKey)
	from sqlalchemy import event
	from sqlalchemy.orm import sessionmaker, scoped_session
	from sqlalchemy.orm import relationship
	from sqlalchemy.ext.declarative import declarative_base, declared_attr
	from sqlalchemy.exc import DBAPIError

	import sqlite3

	# Example nginx + git HTTP Smart mode (git-http-backend) + HTTP Authentication + HTTPS redirect
	# [email protected] - http://jeroen.massar.ch

	server {
	listen 192.0.1.1:80;
	listen [2001:db8::1]:80;

	# Redirect all non-HTTPS traffic to the HTTPS variant
	return 301 https://$host$request_uri;
	}

	PyObject * RustPy_InitModule(const char name, PyMethodDef methods, const char *doc) {
	// return Py_InitModule4(name, methods, doc, (PyObject *) NULL, PYTHON_API_VERSION);
	return Py_InitModule3(name, methods, doc);
	}