RubyConf 2017 Day One

Ruby Conf 2017 Day One

Opening Key note by Matz

Second System Syndrome


Bad changes

Good Changes

  1. Ruby was not designed as fast language, slower than Java and C++ but it’s intentional for programmers to write
  2. Ruby has a lot of constraints, compatibility
  3. Since ruby 2.x every year ruby is getting faster by 5 - 10%
  4. MRI JIT - dream is to make ruby3 3 times faster than ruby2
  5. Goal is to run CRuby in the smallest dyno in heroku (Matz is hired by heroku)

Register Transfer Language (TRL) - Ruby VM

Stack IR vs Register

Current ruby is stack based IR
get a
get b
some opt
puts c
Register based IR
plus a b c

Register based IR

  1. creates less traffic
  2. uses less memory

In one year, YARV was by RTL Vm, which consumes as much memory as 2.4 RTL MJIT Branch

RTL files C files, compiles into .so, then dynmically loaded

Stack based IR vs RTL benchmarks
Error reporting

e.g. did you mean


Byte -> Codepoint -> Grapheme

Controversial changes - still being discussed

Frozen string by default
  1. pro: faster, less memory
  2. con: incompatible
“Real” Keyword arguments
foo(1, option:true) becomes foo(1, {option: true})
  1. pro: faster
  2. con: incomptabile
pattern matching
tail recursion/optimization
  1. pro: faster, no recursion limit
  2. con: confusing backtrace
adding concurrency model
  1. pro: multi-core aware
  2. con: complexity, makes the language less undesrstable

finding error at compile time

Tomorrow, join us from 11:30 - 12 to discuss types and ruby programming langauge. There’s no clear decision yet in these controversial changes, he’d minimize impact (emphasize compatibility)

Release dates

Ruby 2.5

Performance enhancementss

tweet hashtag #ruby25 to help celebrate ruby’s 25th birthday next year

Aside from Matz’s opening keynote, these were some of the other talks that I went to that I found interesting.

(Taking better care of middle) User Error by Olivier Lacan

Programmers are the middle user between end user and the machine We should encourage the community to improve interpreter and compiler errors

improved (accurate error) messages

For example, when missing a parametrized argument to a method, the current version of ruby reports

expected 0 argument and received 1

That’s a bug, the presenter reported it and Nobu fixed it with a patch

more context around errors

Elm is doing a good job about that

Writing Rocket software using Ruby by Nate Berkopec

Compared with the Apollo 11 code

What the program does

  1. initializing a controller
  2. conditional to check the fuel levels before doing something
  3. Sending a man to the moon on a dime-sized memory (only 7 bytes of storage is allowed - an array of size 7)
  4. no multi-threading, box slicing loop: switch to different programs when a time interval is up, prioritize certain programs
  5. yaw for a certain degrees to account for environmental factors like wind

The evolution/best of of the community and talks by Justin Searls and Josh Greenwood

A talk that featured the best of talk videos from past ruby conferences. Including talks about

Matz took the best features from Perl, Lisp, and other programming languages

At the beginning there were a lot of tribal knowledge

Meta Programming in which DHH introduced Rails

The first railscast videos introducing “new” rails features

db:create task Auto timestamps

Code generation 11 years ago is revoluationary, it changed the industry and is now the norm in many other languages.

Heroku was released in 2007

The videos of all these talks will be up soon in Justin’s blog

Closing Keynote: Growing Old by Chad Fowler

This is the first year I am at Ruby Conf without Jim Weichert

Ruby is getting old - Matz from this morning

Years ago, all the feature requests were to make Ruby more like Java. Now all the feature requests are to make Ruby more like TypeScript. Sculpters Gaudi, musicians like Beethoven, the world of fashion, painters and creators of visual poetry all create lasting legacy body of work. We have a problem in the software world. If you write software it might live for five year, I made this up. Good software takes ten years. Get used to it.

How do you create rare OLD still-in-use code that last? I tried to talk to Michael C. Feathers, who wrote the book Working effectively with Legacy Code, and judging from his response he didn’t get my question. My twitter questions also got sarcastic or negative responses.

Step 1: Has to be born.

Few people know that when twitter was born, it was a database-based rails app.

Step 2: Make smaller things and regularly replace them.

Code survives by providing value and being difficult to replace. Biological systems are very much larger than anything (coherent) that people have built. Homeostasis - a balancing process between major organs, such as Brain, Liver - metabolize toxic substances, and Kidney. An inability to maintain homeostatis… result in death. You are dying right now! 3 milion cells die per seoncd out of 50 trillion cells in your body.

What are the oldest surviing software system you regularly use? GNU Linux comes to mind. What else?

C-language toolchain
X-windows system

They’re either small (do one thing and does it well) or large systems.

When do you build a system vs. a cell? Are you building the right one right now?

Cell = tiny components

Make smaler things - Sandi’s talk from 2015 railsconf

All of the problems we cause have the same simple solution… Make smaller classes, make smaller methods, and let them know as little about each other as possible. - Sandi Metz

Kill and replace cells regularly - forces you to work with small components.

Step 3: Deploy

Always deploy. If the system is healthy, and the meta system proves that everything is healthy, we should be able to cycle through the servers constantly and still have 100% uptime.

Rules to keep in mind

The system is the asset, code is a liability.

Immutability - something that we can learn from biological systems. Thinking in terms of pure functions is a way to write tiny components with no side effects.

Never edit a method. Always rewrite it.
Mutability of the system is enhanced by the immutability of its components.
Be conservative in what your produce and liberal in what you can accept.

Loose coupling

Simple interfaces

UNIX pipes
Bull RPC

Assume failure


Tests are actually coupled to your code, so they’re an example of MBTF. Don’t let your tests be an anchor that drags you around. Arguably sometimes it’s better to fix things really fast in production. Experience the worst case scenario so you don’t have to fear it. Delete servers until they crash (perhaps not in production). Chad was the CTO of a company where the code was so in stasis that everyone was afraid to change it.

Create problems that you can react to.

Chaos Monkey (Netflix) Homeostasis Spot instances in AWS, bid on a secondary market for AWS servers and the servers will die in production when price threshold is exceeded. Pinterest switch entirely to spot instances and built services around the failures to deal and recover.

Encapsulation and referential integrity. The Big Rewrite No MORE