1.
Using XP practices on
1960s green screen
technology
The system that time forgot
Brian Leach
Nik Silver

2.
Context

3.
How we went…
from this…
…to
this

4.
Wider Context
• Senior management buy-in
It’s not legacy, it’s a
• More team-working
heritage system.
Knowledge silos and
functional teams.
Pairing, independent teams,
breaking down of knowledge
silos, closer involvement of
stakeholders.

5.
The technology

6.
What is It?
The
What is
UniVerse?
Original
No SQL
Database

7.
1960s
1980s
MySQL
NOSQL
1970s
SYBASE
SQL SERVER
UNIVERSE
UNIX
REALITY
SQL
ORACLE
GIM-1
NELSON
PICK
A History Lesson
1990s

8.
UniVerse BASIC

9.
The UniVerse Business Language
Embedded
Procedural
Runtime Loaded
Data centric
Concurrent
Business focused
No encapsulation
No type-safety
No standard tooling

10.
Do you have global
variables ?
Hell, yes

11.
Challenges from the UniVerse Environment
The database
is NOT a
dependency
Bad Code
is platform
independent

12.
TDD

13.
What engineers were seeing
TDD + FitNesse training for
Java/.NET
Sometimes learning Eclipse,
and Java, too
There was a basic test
“template”
With if/then instead of
assert
Could not see how unit
testing applied to them:
Procedural code
Not designed to be tested
Not part of the culture

14.
The Challenge – In Numbers
•40,000+ concurrent connections
Over 700 lines
of code added
every working
day for 25 years
• 4x HP Superdomes
• 1 million+ reads/machine/second
• 12,000+ programs
• 4,644,481 lines of application code
• 31% have cyc. complexity > 50
• 12 TB changes every day
• 120 software engineers
• ... And growing

15.
Lest we Forget
This application
has powered a
business for
over 25 years
to an annual
turnover of
5 billion pounds

16.
What we did
• Wrote our own framework

Created own refactoring catalogue

Started UniVerse-specific TDD training
• Rewrote the framework

Simpler API

Collaborative effort
• Extended the framework

File configuration

Subroutine fakes

17.
Some Lessons
Learned ..
and shared..
Units are different in UniVerse.
Via refactoring catalogue
The database is under test
Via TDD champions
There are limits to breaking
down procedural code.

Critically, they drive each other

Starting to inherit tests

Community site for discussion of
techniques

18.
Areas of resistance
“It’s a waste of time”
“It takes too long”
“We’re going to throw it away anyway”
“We can’t spend time on it if our product owner doesn’t
prioritise it”
Effective pairing is more difficult with procedural code.

19.
We had to name the framework

20.
We had to name the framework

21.
Git

22.
Experiences Introducing git for UniVerse
• February 2013:

TFS introduced for source control

Very slow

File-driven/fragmented in a central repository
• April 2013:

CloudShop moved to git (practical and strategic),
trigger for similar move for UniVerse
• Ambition:

Switch over in June firebreak, but lots of anguish…

23.
Git Anguish
• Change of workflow

Whole codebase snapshots

File locking
• Inclination to want all problems are solved.
“Git is not suitable
for UniVerse”

24.
Git anguish resolutions… and disappointment
• Regular discussions and
steering
• Some people still use
old editors
• Adjusting world view
• Difficulties with three
way merges
• Git training
• Adopting better tools
• Finally went live in…
September

25.
CI Pipeline

26.
CI Pipeline
Local
Devs
gitlab
listener
Commit
Log
QA
Systems
Packager
System
Release
Area
CI
(pull,make,test,sync)

27.
Consistent reliable environments
• Chaining to/calling fatal errors or stop
• Calls which kill the CI process
• Lots of assumptions about the environment, and
continually challenging to ensure it’s clean.
• Non-compiling programs

28.
CI Surprises
• Needed to clarify the development process
• Engagement around non-compiling code
• Reaction to global CI email
Good results:

Whole codebase compiled for the first time

Real collective ownership

Commits circulated to whole of Engineering
as a matter of pride.

29.
Wrap-up

30.
Achievements
• Human rewards…
• Engineers feel part of the modern world

Hackathon

Coding katas
• Feel invested-in
• Have more transferable skills
• TP held up as an exemplar
• “Best Agile Team” award 2013

31.
Where Next ?
• Improve CI process
• Extend packaging
• BDD
• And on and on…

32.
Sep
Jun
Mar
Dec
Jun Sep
1996
1987
2013
2012
Timeline
Switch-over to git + CI
Start git training for UniVerse
Start building CI pipeline
Target for git switch-over (missed)
Planning git and CI for UniVerse
Started TDD for UniVerse
Cloudshop moves to git
Source control introduced (TFS)
teams start working in step
TDD training starts
Scrum teams arranged
Senior team assembled
New CIO arrives
Coding ....
1996: Migration to UniVerse
1987: Development starts
1987: Development starts
Tech appendix follows…