dim

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

dim

module RedisCluster
  def self.crc16(bytes)
    crc = 0
    bytes.each_byte{|b|
      crc = ((crc<<8) & 0xffff) ^ XMODEMCRC16Lookup[((crc>>8)^b) & 0xff]
    }
    crc
  end

  def self.slot(key)

dim

#!/bin/bash

if [ "$(id -u)" != "0" ]; then
  echo "Sorry, please run with sudo."
  exit 1
fi

echo "deb http://binaries.erlang-solutions.com/debian `lsb_release -c | cut -f2` contrib" | tee /etc/apt/sources.list.d/esl-erlang.list
wget -O - http://binaries.erlang-solutions.com/debian/erlang_solutions.asc | apt-key add -
aptitude update

dim

/* mtest8.c - memory-mapped database tester/toy */
/*
 * Copyright 2013 Dimitrij Denissenko, Black Square Media
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted only as authorized by the OpenLDAP
 * Public License.
 *
 * A copy of this license is available in the file LICENSE in the

dim

# Integration benchmark for redis BITPOS command

require 'redis'
require 'benchmark'

random = Random.new(1)
redis  = Redis.new timeout: 60
bitlen = 10_000
tmpkey = "__rb__bs__"
server = File.expand_path('../src/redis-server', __FILE__)

dim

{
"IAB1": "Arts & Entertainment",
"IAB1-1": "Books & Literature",
"IAB1-2": "Celebrity Fan/Gossip",
"IAB1-3": "Fine Art",
"IAB1-4": "Humor",
"IAB1-5": "Movies",
"IAB1-6": "Music",
"IAB1-7": "Television",
"IAB2": "Automotive",

dim

 # "Performance Scalability of a Multi-Core Web Server", Nov 2007
 # Bryan Veal and Annie Foong, Intel Corporation, Page 4/10
 fs.file-max = 5000000
 net.core.netdev_max_backlog = 400000
 net.core.optmem_max = 10000000
 net.core.rmem_default = 10000000
 net.core.rmem_max = 10000000
 net.core.somaxconn = 100000
 net.core.wmem_default = 10000000
 net.core.wmem_max = 10000000

dim

export function sum(
  forSomeReasonThisIsAVeryLongVariableName1: number,
  forSomeReasonThisIsAVeryLongVariableName2: number,
): number {
  return (
    forSomeReasonThisIsAVeryLongVariableName1 +
    forSomeReasonThisIsAVeryLongVariableName2
  );
}

dim

S2 Geometry Cell Sizes - http://s2geometry.io/

Script

package main

import (
	"flag"
	"fmt"

dim

default: bench

bench:
	go test -run=NONE -bench=. -benchmem