netologist

#Rob Pike's 5 Rules of Programming

##Rule 1. You can't tell where a program is going to spend its time. Bottlenecks occur in surprising places, so don't try to second guess and put in a speed hack until you've proven that's where the bottleneck is.

##Rule 2. Measure. Don't tune for speed until you've measured, and even then don't unless one part of the code overwhelms the rest.

##Rule 3. Fancy algorithms are slow when n is small, and n is usually small. Fancy algorithms have big constants. Until you know that n is frequently going to be big, don't get fancy. (Even if n does get big, use Rule 2 first.)

netologist

Code is clean if it can be understood easily – by everyone on the team. Clean code can be read and enhanced by a developer other than its original author. With understandability comes readability, changeability, extensibility and maintainability.

---

General rules

1. Follow standard conventions.
2. Keep it simple stupid. Simpler is always better. Reduce complexity as much as possible.
3. Boy scout rule. Leave the campground cleaner than you found it.
4. Always find root cause. Always look for the root cause of a problem.

Design rules

netologist

Vault Examples

Examples highligthing different Vault features.

To have a list of valid CLI flags, use

vault -h
vault <FEATURE> -h

HA Replication

netologist

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

netologist

import time
import asyncio
import requests

domain = 'http://integralist.co.uk'
a = '{}/foo?run={}'.format(domain, time.time())
b = '{}/bar?run={}'.format(domain, time.time())

async def get(url):
   print('start: ', url)

netologist

<!DOCTYPE NETSCAPE-Bookmark-file-1>
<!-- This is an automatically generated file.
     It will be read and overwritten.
     DO NOT EDIT! -->
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8">
<TITLE>Bookmarks</TITLE>
<H1>Bookmarks</H1>
<DL><p>
    <DT><H3 ADD_DATE="1604897638" LAST_MODIFIED="0" PERSONAL_TOOLBAR_FOLDER="true">Bookmarks bar</H3>
    <DL><p>

netologist

#!/bin/sh
if [ "$1" == "" ]; then
  echo "Usage: $0 <PROJECT_ROOT> <GITHUB_REPO>"
  exit 1
fi
if [ "$2" == "" ]; then
  echo "Usage: $0 <PROJECT_ROOT> <GITHUB_REPO>"
  exit 1
fi

netologist

# to generate your dhparam.pem file, run in the terminal
openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048

netologist

include $(GOROOT)/src/Make.inc

GOFMT=gofmt -spaces=true -tabindent=false -tabwidth=4

all:
	$(GC) jsontest.go 
	$(LD) -o jsontest.out  jsontest.$O

format:
	$(GOFMT) -w jsontest.go

netologist

Sublime Text 2 – Useful Shortcuts (Mac OS X)

General

⌘T	go to file
⌘⌃P	go to project
⌘R	go to methods
⌃G	go to line
⌘KB	toggle side bar
⌘⇧P	command prompt