Ruby PerformanceThe Last Mile

Charles Oliver Nutter @headius

I've spent ten years building

I love Ruby

I want Ruby to succeed

I believe JRuby is the way

Do you want performance today?

Do you want concurrency today?

Do you know JRuby?

What you love from Ruby• Latest Ruby language features

• Mostly-same Ruby standard library

• Pure-Ruby gems work great

• Native gems with JRuby support

• It walks like Ruby, talks like Ruby

• It is Ruby!

With the power of the JVM

• Fast JIT to native code

• Fully parallel threading

• Leading-edge garbage collectors

• Access to Java, Scala, Clojure, ...

• But it's still Ruby!

Do you know Jay?

Matz's Keynote

Performance

Concurrency

By 2020

But what about today?

Performance

What do you optimize for?

• Easy to develop with: short time until first deploy

• Fast startup: good response cycle at command line

• Straight-line performance, many operations per second

• Parallelism: utilize many cores to get more done

State of the Art: Production-quality Rubies

Production Quality?• Support for 99%+ of Ruby language features

• Important parts of standard library

• Runs typical Ruby applications and libraries

• Healthy extension ecosystem

• CRuby, JRuby are the only real options right now

CRuby (MRI)• Up until 1.9, AST interpreter

• YARV bytecode VM introduced for 1.9.0

• GC and performance improvements through 2.x series

• Ruby 2.3 is latest, released in December

• Future work on JIT, GC, happening now

JRuby• Many redesigns since creation in 2001

• AST interpreter until 2007

• Simple AST-to-bytecode JIT until JRuby 9000

• Optimizing compiler with JIT for 9k

• JRuby 9.0.5 is current, 9.1 in a couple weeks

• Next-gen Truffle runtime in the works

Lies, damn lies, and benchmarks

CRuby: red/black tree

0

2

4

6

8

1.8.7 1.9.3 2.0 2.1 2.2 2.3

CRuby: red/black tree

0

0.625

1.25

1.875

2.5

1.8.7 1.9.3 2.0 2.1 2.2 2.3

JRuby: red/black tree

0

1.25

2.5

3.75

5

JRuby 9.1 CRuby 2.3

JRuby: red/black tree

0

1.25

2.5

3.75

5

JRuby 9.1 CRuby 2.3

JRuby: red/black tree

0

0.6

1.2

1.8

2.4

JRuby 9.1 CRuby 2.3

4x FASTER

Ruby Code

Ruby Code

ParserJRuby AST

Parser

JRuby AST

Com

piler

JRuby IR

Com

piler

JRuby IR

JIT

JVM Bytecode

What can we do with this?

Block Pass-throughdef foo(&b) bar(&b) enddef bar yieldend

Block Pass-throughloop { puts Benchmark.measure { i = 0 while i < 1_000_000 i+=1 foo { }; foo { }; foo { }; foo { }; foo { } end } }

Block Passing

0

0.55

1.1

1.65

2.2CRuby 2.3 JRuby 1.7.24 JRuby 9.1

define_method

define_method :add do |a, b| a + b end

define_method

0

0.25

0.5

0.75

1CRuby 2.3 JRuby 1.7.24 JRuby 9.1

Postfix rescue

foo rescue nil

csv.rb Converters

Converters = { integer: lambda { |f| Integer(f.encode(ConverterEncoding)) rescue f }, float: lambda { |f| Float(f.encode(ConverterEncoding)) rescue f },

Postfix rescue

0

3.5

7

10.5

14CRuby 2.3 JRuby 9.1

0

3.5

7

10.5

14CRuby 2.3 JRuby 9.1

Postfix rescue

CRuby starts up the fastest

JRuby runs the fastest

And we're getting faster

Concurrency

Parallelism

Concurrency? Parallelism?

• Parallelism happens on the harder, e.g. multi-core

• Concurrency happens in the software, e.g. Thread API

• You can have concurrency without parallelism

• You can have both with JRuby

Parallelism in Ruby• On CRuby, usually process-level

• Ruby threads prevented from running in parallel

• Extensions, IO can opt to release lock

• On JRuby, usually thread-level

• Ruby thread == JVM thread == OS thread

• Single-process, shared memory

A Mailing Queue• A simple example of concurrency

• For each job, construct an email to send

• Some computation added to make processing heavier

• "Ruby Concurrency and Parallelism: A Practical Tutorial" https://www.toptal.com/ruby/ruby-concurrency-and-parallelism-a-practical-primer

require "./lib/mailer"require "benchmark"puts Benchmark.measure{ (ARGV[0] || 10_000).times do |i| Mailer.deliver do from "eki_#{i}@eqbalq.com" to "jill_#{i}@example.com" subject "Threading and Forking (#{i})" body "Some content" end end }

POOL_SIZE = (ARGV[0] || 10).to_ijobs = Queue.new(ARGV[1] || 10_000).to_i.times{|i| jobs.push i} workers = (POOL_SIZE).times.map do Thread.new do begin while x = jobs.pop(true) Mailer.deliver do ... end end rescue ThreadError end endendworkers.map(&:join)

CRuby: mailer * 1000Ti

me

in S

econ

ds

0

37.5

75

112.5

150

synchronous 4 threads 4 forks

JRuby: mailer * 1000

0

7

14

21

28

Synchronous 4 Threads

JRuby vs MRITimes Improvement

0

0.85

1.7

2.55

3.4

CRuby Forks JRuby Threads

3.37x3.09x

But Threads are bad, right?

Most users will never Thread.new

You'll deploy one Rails server for your entire site

You'll cut your instances ten times

Or maybe 100 times

Libraries and frameworks will Thread.new for you

And on JRuby, you'll have more efficient apps

So we're done?

Move to JRuby

Now your app is fast!

Right?

It is possible to write efficient Ruby code

But it's very easy to write inefficient Ruby code

Great Features, Hidden Costs• Blocks are expensive to create, slower than method calls

• case/when is an O(n) cascade of calls

• Singleton classes/methods are costly and hurt method cache

• Literal arrays, hashes, strings have to be constructed, GCed

• Flow-control exceptions can be very expensive and hard to find

What happens if your code does not run fast enough?

You need to know your app

You need good tools

And the JVM has great tools

CRuby Tooling

• Basic GC stats built in

• Simple profilers in standard library

• Some third-party tools

• stackprof, ruby-prof, perftools.rb, ...

JVM tooling is JRuby tooling

JVM Tooling

• Wide range of GCs: parallel, concurrent, realtime, pauseless

• Built-in tools for analyzing GC, JIT, thread, IO, heap

• Built-in remote monitoring via JMX

• Dozens of tools out there for profiling, management, and more

VisualVM• Graphical console into your application

• Monitor GC, threads, CPU usage

• Sampled or full profiling with GUI browser

• Live memory dumping, heap inspection

• Ships with every OpenJDK install

Java Mission Control

• Extremely low-overhead application recording

• Analyze results offline in JMC

• GC, CPU, heap events, IO operation all browsable

• Commercial feature, free for development use

More on GC

• JVM GCs are incredibly tunable with sensible defaults

• Tools like http://gceasy.io and JClarity give you a deeper view

• These are the best GCs and the best tools in the world

Finding Bottlenecks

Profiling

Profiling Tools

• Command line options: --profile, --sample

• JVM command-line profilers like prof

• Many graphical sampling/complete profiling options

• Flame graphs, stack profilers, you name it!

...and this is just the beginning

Wrapping Up

Ruby is alive and well

CRuby continues to improve

Ruby 3 is very exciting

JRuby is performance today

JRuby is concurrency today

JRuby has tools today

JRuby makes you happier!

Thank You!Charles Oliver Nutter

headius@headius.com @headius

http://jruby.org https://github.com/jruby/jruby