Controlled Chaos: A Case Study Of Introducing Rails Into An Operational NASA System - RailsConf 2011

Controlled Chaos
A case study of introducing Rails into an
operational NASA system

Dan Pilone / Jason Gilman

RailsConf 2011 - Controlled Chaos - Dan Pilone - Jason Gilman

Wednesday, June 1, 2011

ECHO Key Metrics

Support 13 Data Centers
3200 Earth Science Datasets
~100M pieces of science information
~100% uptime*

RailsConf 2011 - Controlled Chaos - Dan Pilone - Jason Gilman *excluding planned maintenance


Why are we talking about this...



http://pastorweasel.blogspot.com/



Why did we do it?



Problem had changed



WIST

ECHO

ECHO
DB



Technology had changed



WIST

Perl

ECHO
<!DOCTYPE xml PUBLIC “-//W3C//DT
<html> bgcolor="red">
<body
<?xml
<html> bgcolor="red">
<body
<h1>
<h1>
<body shouldn't be static.
This bgcolor="red">
This shouldn't be static.
</h1> <h1>
</h1> This shouldn't be static.
</body>
</body> </h1>
ECHO </html>
</html> </body>
DB </html>



??????

ECHO

ECHO
DB
?


WIST

ECHO

ECHO
DB

REST API...


But there was hope...



Agile Process



Very Talented Team



Fantastic Customer and
Management support



What did we want?



Happy customer



Top Notch Client



Happy Developers



Quality Development
Experience



We had about 10 months...



...and 4 developers...



We went shopping.



RailsConf 2011 - Controlled Chaos - Dan Pilone - Jason Gilman http://www.cheapbeast.com/proﬁle-vicky


Prototyping is hard.



Developers are harder.



Why Rails?

Lots of community “sell”
JRuby gave us a transition path*
RailsConf



What Rails offered us

Developer interest and excitement
Clearly the right tool for the job
Hoped for a signiﬁcantly reduced code base
Hoped for rapid development and releases



What did this impact?



Everything.



Java Developers



List<String> names = new
ArrayList<String>();

Java Developers




Java Developers

expe
rts!




Java Developers

expe
rts! Monthly Iteration




Java Developers
Dedicated Test
Team expe
rts! Monthly Iteration



First Attempts



Adopting a new language



ACTFL Stages

1. Novice
2. Intermediate
3. Advanced
4. Superior

http://www.languagetesting.com/scale.htm
http://www.sil.org/lingualinks/languagelearning/otherresources/
gudlnsfralnggandcltrlrnngprgrm/IntroductionToGuidelinesForALa.htm


Novice

Can not hold a conversation
"memorized survival phrases"
"Where is the bathroom?"
"What time is it?
"Check, please."



Novice Equivalent

$ rails generate scaffold
Post name:string title:string
content:text



Intermediate
Conversations with pauses,
inaccuracies, and self
corrections
Struggle to answer questions
"vocabulary and syntax are
strongly inﬂuenced by their ﬁrst
language"
"I + want + beer + for + me +
drink"


Intermediate Equivalent
class Person
def getName()
@name
end

def setName(newName)
@name = newName
end

def self.getNames(peopleList)
nameList = Array.new()
for(person in peopleList)
nameList.push(person.getName())
end
return nameList
end
end



Advanced

"connected narrative discourse"
"comprehend language related to
a vast range of topics, situations
and contexts"
"easily process many social
nuances"



Advanced Equivalent

class Person
include XmlSerializer

attr_accessor :name

def self.names(people)
people.map &:name
end
end



Superior
"increasing facility in
abstract and hypothetical
discussions"
"provide lengthy and
coherent narrations, all
with ease, ﬂuency, and
accuracy"
Ability to speak at length
on abstract topics
without hesitation.



Superior Equivalent

module ActiveRecord
class Base
def method_missing(method_id, *arguments, &block)
# generates find_by_field type methods ...
end
end
end



100%

75%

50%

25%

0%
Novice Intermediate Advanced Superior



Everyone starts here
100%

75%

50%

25%

0%



100%

2 weeks to 2 months
75%

50%

25%

0%



100%

2 weeks to 2 months
75%
3 - 6 months
50%

25%

0%



8 months to a year
100%

2 weeks to 2 months
75%
3 - 6 months
50%

25%

0%



We got a little better...



git



celerity git
jasmine
mocha
FactoryGirl formtastic
soap4r rspec echoe

jammit
sass
cucumber capybara
nokogiri rufus minitest

webrat 2011 - Controlled Chaos - Dan Pilone - Jason Gilman xmlsimple
RailsConf
TestUnit

Deadlines were getting closer

Developer unrest
Working long hours
We weren't getting things done



http://www.ﬂickr.com/photos/ewwhite/4462922520/


Java
• Got things done
• Dissatisﬁed by the technology
• Bored

Unhappy


Rails
•We weren't getting things done
•Technology Unfamiliarity
•Frustrated

Unhappy


Developer Happiness

Challenged

Meaningful Work Language

Workplace

?



Developer Happiness

Challenged

Meaningful Work Language

Productivity Workplace

?



Am I trying to understand a business problem or am I
trying to ﬁgure out why bundle install just failed?



http://www.ﬂickr.com/photos/ladybeames/2896787167/


Addressing the problems

Disciplined refactoring and introduction of new gems
Communication
Brown bags
Chat rooms
Pair programming
Wiki



http://www.ﬂickr.com/photos/camknows


Things we worried about...

Maintainability
Technical longevity
Learning Curve
Developer buy-in



...but didn’t need to.

Maintainability
Technical longevity
Learning Curve
Developer buy-in



...but didn’t need to.
Lines of code

300000
Maintainability
225000
Technical longevity
150000
Learning Curve
Developer buy-in 75000

0
WIST Reverb + REST



What were the real problems?

http://www.ﬂickr.com/photos/stuant63/2255781557


Real Problems

Learning curve
Constant refactoring
Cucumber testing is hard to get right
Proliferation of technologies



Better than expected...

Ruby language productivity
Metaprogramming application to domain problems
Wide availability and applicability of gems
Community (enthusiasm, meet ups, speed of
improvements in technology)



It’s just Ruby 1.9

Gave us a transition path and ROI on our Java

All the beneﬁts of the JVM - performance, threading,
GC, etc.

Combined with Warbler allows us to leverage existing
deployment model



It’s just Ruby 1.9

Gave us a transition path and ROI on our Java

All the beneﬁts of the JVM - performance, threading,
GC, etc.

Combined with Warbler allows us to leverage existing
deployment model
But we actually reused less Java than we thought...



Time on a
logarithmic
scale!
REXML

source: http://www.rubyinside.com/ruby-xml-performance-benchmarks-1641.html



Generated
WSDL Java

JAXB
Schemas spring-ws



Would we do it again?



Absolutely



What would we have done
differently?
Not a whole lot
Consultants?
Training?
Medium sized pilot project?
Address build and deployment approaches earlier?



Key Take-aways

It will impact everything
Communication is essential
Rails has been a good choice but..
Dependent on team and management to pull it off
Developer happiness = Developer Productivity
Control the change



Questions?

Dan Pilone - @danpilone
http://spkr8.com/t/7577
Jason Gilman - @jasongilman

Controlled Chaos: A Case Study Of Introducing Rails Into An Operational NASA System - RailsConf 2011

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Controlled Chaos: A Case Study Of Introducing Rails Into An Operational NASA System - RailsConf 2011