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@jboner
jboner / latency.txt
Last active July 2, 2025 06:46
Latency Numbers Every Programmer Should Know
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
package main
import (
"flag"
"fmt"
"github.com/miekg/dns"
"os"
)
var (
@stelcheck
stelcheck / hbase.rest.scanner.filters.md
Created October 30, 2012 10:00
HBase Stargate REST API Scanner Filter Examples

Stargate Scanner Filter Examples

Introduction

So yeah... no documentation for the HBase REST API in regards to what should a filter look like...

So I installed Eclipse, got the library, and took some time to find some of the (seemingly) most useful filters you could use. I'm very green at anything regarding HBase, and I hope this will help anyone trying to get started with it.

What I discovered is that basically, attributes of the filter object follow the same naming than in the documentation. For this reason, I have made the link clickable and direct them to the HBase Class documentation attached to it; check for the instantiation argument names, and you will have your attribute list (more or less).

@jedi4ever
jedi4ever / dns tuning ssh login speedup vagrant
Created May 27, 2013 13:37
speeding up DNS/SSH connections in vagrant
- Tune /etc/ssh/sshd_config
UseDNS no # Disable DNS lookups
GSSAPIAuthentication no # Disable negotation of slow GSSAPI
don't forget to restart it, use a script provider to set it , or create it with veewee or snapshot it
- Tune Vagrantfile
vb.customize ["modifyvm", :id, "--natdnshostresolver1", "on"]
@allex
allex / gist:11203573
Last active June 3, 2024 13:32
Ubuntu 安装中文字体

环境 (Environment)

版本:Ubuntu 14.04 LTS 默认语言:English(United States)

安装 (Setup)

Debian 和 Ubuntu 下对中文支持比较好的字体有: fonts-droid、ttf-wqy-zenhei 和 ttf-wqy-microhei 等,除了文泉驿系列字体外,比较流行的免费中文字体还有文鼎提供的楷体和上海宋,包名分别是: fonts-arphic-ukai 和 fonts-arphic-uming。

#!/bin/sh
remove_dangling() {
echo "Removing dangling images ..."
docker rmi $(docker images -f dangling=true -q)
}
remove_stopped_containers() {
echo "Removing stopped containers ..."
docker rm $(docker ps -qa)
@pnc
pnc / observer.md
Last active April 1, 2025 21:38
Using Erlang observer/appmon remotely

Using OTP's observer (appmon replacement) remotely

$ ssh remote-host "epmd -names"
epmd: up and running on port 4369 with data:
name some_node at port 58769

Note the running on port for epmd itself and the port of the node you're interested in debugging. Reconnect to the remote host with these ports forwarded:

$ ssh -L 4369:localhost:4369 -L 58769:localhost:58769 remote-host
@P7h
P7h / tmux__CentOS__build_from_source.sh
Last active May 2, 2024 01:27
tmux 2.0 and tmux 2.3 installation steps for Ubuntu. Or build from tmux source v2.5 for Ubuntu and CentOS.
# Steps to build and install tmux from source.
# Takes < 25 seconds on EC2 env [even on a low-end config instance].
VERSION=2.7
sudo yum -y remove tmux
sudo yum -y install wget tar libevent-devel ncurses-devel
wget https://github.com/tmux/tmux/releases/download/${VERSION}/tmux-${VERSION}.tar.gz
tar xzf tmux-${VERSION}.tar.gz
rm -f tmux-${VERSION}.tar.gz
cd tmux-${VERSION}
@romainl
romainl / .ctags
Last active September 8, 2024 10:26
My ctags config
--langdef=less
--langmap=less:.less
--regex-less=/^[ \t&]*#([A-Za-z0-9_-]+)/\1/i,id,ids/
--regex-less=/^[ \t&]*\.([A-Za-z0-9_-]+)/\1/c,class,classes/
--regex-less=/^[ \t]*(([A-Za-z0-9_-]+[ \t\n,]+)+)\{/\1/t,tag,tags/
--regex-less=/^[ \t]*@media\s+([A-Za-z0-9_-]+)/\1/m,media,medias/
--regex-less=/^[ \t]*(@[A-Za-z0-9_-]+):/\1/v,variable,variables/
--regex-less=/\/\/[ \t]*(FIXME|TODO)[ \t]*\:*(.*)/\1/T,Tag,Tags/
--langdef=scss
@janlay
janlay / README.md
Last active March 20, 2025 13:05
Yet another config for Surge.app

Install

  1. Modify index.txt with your output path and proxy info
  2. Use Text Builder to build configuration for Surge: $ text-builder -index /path/to/index.txt Or run $ sh build-all to build all your index files.
  3. Import configuration via AirDrop/iTunes/Dropbox/iCloud

本人不提供任何保证和技术支持,使用者自负风险。
There are no guarantees, no any support. Use it at your own risk.