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#!/usr/bin/env bash

set -o errexit
set -o nounset
set -o pipefail

IAM_GROUP=${1:-admins}
EKS_ROLE_ARN=${2:-arn:aws:iam::111122223333:role/eks-node-role}
RBAC_GROUP=${3:-system:masters}

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-- based on http://stackoverflow.com/questions/21767780/how-to-find-size-of-database-schema-table-in-redshift
SELECT name AS table_name, ROUND((COUNT(*) / 1024.0),2) as "Size in Gigabytes"
FROM stv_blocklist
INNER JOIN
(SELECT DISTINCT id, name FROM stv_tbl_perm) names
ON names.id = stv_blocklist.tbl
GROUP BY name
ORDER BY "Size in Gigabytes" DESC

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# Ask for the user password
# Script only works if sudo caches the password for a few minutes
sudo true

# Install kernel extra's to enable docker aufs support
sudo apt-get -y install linux-image-extra-$(uname -r)

# Add Docker PPA and install latest version
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 36A1D7869245C8950F966E92D8576A8BA88D21E9
sudo sh -c "echo deb https://get.docker.io/ubuntu docker main > /etc/apt/sources.list.d/docker.list"

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#!/usr/bin/env ruby

progress = 'Progress ['
1000.times do |i|

# i is number from 0-999
j = i + 1

  # add 1 percent every 10 times
  if j % 10 == 0

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# post_loc.txt contains the json you want to post
# -p means to POST it
# -H adds an Auth header (could be Basic or Token)
# -T sets the Content-Type
# -c is concurrent clients
# -n is the number of requests to run in the test

ab -p post_loc.txt -T application/json -H 'Authorization: Token abcd1234' -c 10 -n 2000 http://example.com/api/v1/locations/

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#!/bin/sh
# OS: Ubuntu 14.01
# Generate data - produces about 200GB on disk, takes a while

DATADIR=tpch-dbgen
SCALE=1000

git clone https://github.com/electrum/tpch-dbgen.git
cd $DATADIR && make && ./dbgen -f -v -C 16 -S 1 -s $SCALE && cd -

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# SSL request to hostname that is not in DNS

> curl -o /dev/null -w @curlformat https://beta.finance.yahoo.com
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  255k    0  255k    0     0   233k      0 --:--:--  0:00:01 --:--:--  233k

Size:     261255
DNS:      0.522
Connect:  0.536

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MySQL

Getting started:

• http://www.sqlteaching.com/
• https://www.codecademy.com/courses/learn-sql

Related tutorial: http://cd64.de/mysql-cli

SQL joins infografic: http://cd64.de/sql-joins

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Latency Comparison Numbers
--------------------------
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
Send 1K bytes over 1 Gbps network        10,000   ns    0.01 ms
Read 4K randomly from SSD*              150,000   ns    0.15 ms

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package main

import (
	"net/http"
)

type SingleHost struct {
	handler     http.Handler
	allowedHost string
}