Slides from a talk I gave at CodeFellows in January 2014

1. !
An Introduction to Go
given January 30, 2014 at CodeFellows
Zack Hubert

2. Hi, I’m Zack

3. I work here…and…

4. I think Go is Awesome

5. I think you’ll like it
too

6. My Story with Go

7. The Year was 2012
•
It was a NEW PROJECT!
•
Make it Real Time
•
Use a Javascript MVC

8. Ruby on Rails
Server side choice was easy…

9. What about the
Client Side?

10. logos believed to be fair use

11. Batman.js
Has been a great choice

12. What kind of product?
Resource Scheduling

13. “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?”
–Our Customers

14. Rails
Performance
< 150ms?
This could be a problem.

15. Solution
MySQL Upserts
Histogram the Schedule
Heavily Precompute Values in Cache

16. It Worked!

17. The Good
•
40ms
•
Rails+MySQL
•
No NoSQL
•
Same stack as other apps

18. The Bad
•
Millions of rows of computed values
•
Caching is error prone
•
Data model polluted with derivative classes

19. Free Week - 2012
•
Looked at Go for an API
•
Didn’t understand it
•
Frustrated by many things
•
Compiler error on unused import…wha!?

20. Go is Opinionated
frustration will ensue without knowing the opinions of
the designers

21. Back to Resources
•
1.5 years later…many users etc.
•
The app was getting slower (larger JSON
responses)
•
Complexity was an increasing burden

22. Techempower JSON encoding benchmark
http://www.techempower.com/benchmarks
bottom is visible :(

23. Free Week - 2013
•
Had been reading up in the intervening year
•
Watched every video I could
•
and then it made sense…

24. 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)

25. RUSH Performance
•
100x faster than the heavily cached Ruby
option
•
1,000x faster than Ruby without caching
•
1% of the memory footprint

27. Go turns out to be the best at JSON
…a perfect complement, huzzah :)

28. Why Learn Go?

29. Why Learn Go?
•
Crazy fast
•
Awesome complement to JS MVC
•
Great service carveout to help an
interpreted language web framework like
Ruby on Rails

30. FUN!

31. Overview
•
A brief history of Go
•
Language design decisions

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

33. 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 :)

34. The Story of Go

35. Rob Pike
Bell 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

36. Ken Thompson (seated)
designed UNIX, B, Plan 9, Turing award
image cc by-sa 2.0 at en.wikipedia.org

37. 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

38. The Creation Story
long C++ build, 45 minutes, whiteboarded the language
image still from Google I/O 2012

39. Open Sourced Nov, 2009
464 contributors as of January 26, 2014

40. Already Quite Popular
(SO vs Github)

41. Problem #1:
Development Speed

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

43. Fast is FUN

44. Fast has its
Tradeoffs
“Missing” language features - Generics, Inheritance,
etc.

45. and its quirks
managed imports for instance…but it makes sense
from the creation

46. Problem #2:
Make it Modern

47. Age of Languages?

48. C++ 1979

49. Python 1989

50. Java 1990

51. Ruby 1993

52. Go - 2007
(14 years after Ruby)

53. Modern Means
Multicore

54. Multicore/Concurrency
•
Concurrency through CSPstyle 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

55. Concurrency is
HUGE in Go

56. Modern Means
Internet
it’s kind of a big deal

57. 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

58. Problem #3:
Complexity

59. Webscale.
large programs, big teams.

60. Seriously though…
•
Designed to be C-like for early career
programmers
•
Simplified syntax

61. 1 keyword for
looping
Simple

62. Garbage Collection
Simple, easier with concurrency

63. 25 keywords total
50 in Java, 48 in C++, ~42 in Ruby

64. No Inheritance
Composition is easier to get right, defers design
decisions

65. CSP Concurrency
Mutexes are hard to get right. Channels are easier.

66. So…when Go is
confusing ask…

67. Is this because the
language is YOUNG?

68. Is this because it’s
SIMPLE?

69. Is this because it
wants to be FAST?

70. Revised…
Original talk proceeded to 1 hour Tour of Go
and then “The Fun Part”
(hands-on with Go, using D&D imagery)

71. Keep on Learnin’
•
http://golang.org
•
http://gobyexample.org
•
http://gophercasts.io

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

73. Let’s Have Some
Questions