!

An Introduction to Gogiven January 30, 2014 at CodeFellows

Zack Hubert

Hi, I’m Zack

I work here…and…

I think Go is Awesome

I think you’ll like it too

My Story with Go

The Year was 2012

• It was a NEW PROJECT!

• Make it Real Time

• Use a Javascript MVC

Ruby on RailsServer side choice was easy…

What about the Client Side?

logos believed to be fair use

Batman.jsHas been a great choice

What kind of product?Resource Scheduling

–Our Customers

“For an event that occurs weekly from 7-9pm on Wednesdays, Fridays (except 3 weeks...) are five out of ten chairs available along with three tables to go in the Green room and

make sure Bill approves?”

Rails Performance

< 150ms? This could be a problem.

SolutionMySQL Upserts

Histogram the Schedule Heavily Precompute Values in Cache

It Worked!

The Good

• 40ms

• Rails+MySQL

• No NoSQL

• Same stack as other apps

The Bad

• Millions of rows of computed values

• Caching is error prone

• Data model polluted with derivative classes

Free Week - 2012

• Looked at Go for an API

• Didn’t understand it

• Frustrated by many things

• Compiler error on unused import…wha!?

Go is Opinionatedfrustration will ensue without knowing the opinions of

the designers

Back to Resources

• 1.5 years later…many users etc.

• The app was getting slower (larger JSON responses)

• Complexity was an increasing burden

Techempower JSON encoding benchmark

http://www.techempower.com/benchmarks bottom is visible :(

Free Week - 2013

• Had been reading up in the intervening year

• Watched every video I could

• and then it made sense…

RUSH is Born• Resource Utilization Service Handler

• Day 1 - Working Service

• Day 2 - Accurate Service

• Week 1 - Production Ready

• Launched Post Holidays

• Rock solid.

• (word play on my favorite band)

RUSH Performance

• 100x faster than the heavily cached Ruby option

• 1,000x faster than Ruby without caching

• 1% of the memory footprint

Go turns out to be the best at JSON

…a perfect complement, huzzah :)

Why Learn Go?

Why Learn Go?

• Crazy fast

• Awesome complement to JS MVC

• Great service carveout to help an interpreted language web framework like Ruby on Rails

FUN!

Overview

• A brief history of Go

• Language design decisions

What is Go?Go is a new, general-purpose programming language.

What is Go?• Compiled: compiler makes

runnable binary

• Statically typed: compiler checks for a category of mistakes

• Concurrent: easy composition of processes, (may be simultaneously executed)

• Garbage Collected: runtime release of no longer used memory

• Simple: as classically defined :)

The Story of Go

Rob PikeBell Labs

Unix team created Plan 9/Inferno os co-author with Kernighan

(Unix Programming Environment)

co-creator of UTF-8 (with Ken)

image cc by-sa 3.0 chlor at en.wikipedia.org

Ken Thompson (seated)designed UNIX, B, Plan 9, Turing award

image cc by-sa 2.0 at en.wikipedia.org

Robert Griesemer

V8, Chubby for GFS, Java HotSpot VM, compiler for Cray Y-MP, interpreter for

APL

image cc by-sa 3.0 at en.wikipedia.org

The Creation Storylong C++ build, 45 minutes, whiteboarded the language

image still from Google I/O 2012

Open Sourced Nov, 2009464 contributors as of January 26, 2014

Already Quite Popular(SO vs Github)

Problem #1: Development Speed

Development Speed

• “It's a fast statically typed compiled language that feels like a dynamically typed interpreted language.” - golang.org

Fast is FUN

Fast has its Tradeoffs

“Missing” language features - Generics, Inheritance, etc.

and its quirksmanaged imports for instance…but it makes sense

from the creation

Problem #2: Make it Modern

Age of Languages?

C++ 1979

Python 1989

Java 1990

Ruby 1993

Go - 2007(14 years after Ruby)

Modern Means Multicore

Multicore/Concurrency• Concurrency through CSP-

style processes called go routines

• 1978 CSP by Sir Tony Hoare

• M:N runtime mapping of green threads to system threads

• “Do not communicate by sharing memory, instead share memory by communicating” - Pike

image by Rama cc by-sa 2.0-fr at en.wikipedia.org

Concurrency is HUGE in Go

Modern Means Internetit’s kind of a big deal

The Internet Age

• Go ships with a “batteries included” standard library

• For instance, net/http

• Instead of frameworks to pick up the slack, the std-lib has most of what you need

Problem #3: Complexity

Webscale.large programs, big teams.

Seriously though…

• Designed to be C-like for early career programmers

• Simplified syntax

1 keyword for looping

Simple

Garbage CollectionSimple, easier with concurrency

25 keywords total50 in Java, 48 in C++, ~42 in Ruby

No InheritanceComposition is easier to get right, defers design

decisions

CSP ConcurrencyMutexes are hard to get right. Channels are easier.

So…when Go is confusing ask…

Is this because the language is YOUNG?

Is this because it’s SIMPLE?

Is this because it wants to be FAST?

Revised…Original talk proceeded to 1 hour Tour of Go

and then “The Fun Part” (hands-on with Go, using D&D imagery)

Keep on Learnin’

• http://golang.org

• http://gobyexample.org

• http://gophercasts.io

Thank You!@zhubert, http://www.zhubert.com

Let’s Have Some Questions