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

aponxi

SQL to MongoDB Mapping Chart

SQL to MongoDB Mapping Chart¶

In addition to the charts that follow, you might want to consider the Frequently Asked Questions section for a selection of common questions about MongoDB.

Executables¶

The following table presents the MySQL/Oracle executables and the corresponding MongoDB executables.

KartikTalwar

The fastest remote directory rsync over ssh archival I can muster (40MB/s over 1gb NICs)

This creates an archive that does the following:

rsync (Everyone seems to like -z, but it is much slower for me)

• a: archive mode - rescursive, preserves owner, preserves permissions, preserves modification times, preserves group, copies symlinks as symlinks, preserves device files.
• H: preserves hard-links
• A: preserves ACLs

billautomata

# local port forwarding
# the target host 192.168.0.100 is running a service on port 8888
# and you want that service available on the localhost port 7777

ssh -L 7777:localhost:8888 user@192.168.0.100

# remote port forwarding
# you are running a service on localhost port 9999 
# and you want that service available on the target host 192.168.0.100 port 12340

cecilemuller

How to setup Let's Encrypt for Nginx on Ubuntu 18.04 (including IPv6, HTTP/2 and A+ SLL rating)

---

Virtual hosts

Let's say you want to host domains first.com and second.com.

Create folders for their files:

BretFisher

Docker Cli Tips and Tricks

• bret@bretfisher.com
• https://twitter.com/BretFisher
• http://bretfisher.com

My favorite command line options and best practices

• Bash/zsh completion
• use Tab to populate command line, narrows down options as you go, fills in container names, ID's, images, volumes. Huge time saver.

nickkraakman

FFmpeg Cheat Sheet for 360º video

Brought to you by Headjack

 
FFmpeg is one of the most powerful tools for video transcoding and manipulation, but it's fairly complex and confusing to use. That's why I decided to create this cheat sheet which shows some of the most often used commands.

 
Let's start with some basics:

• ffmpeg calls the FFmpeg application in the command line window, could also be the full path to the FFmpeg binary or .exe file

jproney

PicoCTF 2017: ECC2

A 1064CBread Writeup

Problem

In the file handout.txt, we are given the following parameters for an elliptic curve:

• y^2 = x^3 + A*x + B mod M -- the curve equation
• M -- the modulus of the curve

creack

package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	"os"
	"os/signal"
	"strconv"

felixlindemann

rsync -rtXx --numeric-ids --progress -e "ssh -T -c aes128-ctr -o Compression=no -x" <user>@<ip>:/<source-path>/ /<dest.path>/