Orchestration and

the New York Subway May you live in interesting times

David Lutterkort Puppet Labs @lutterkort

http://www.theatlantic.com/technology/archive/2015/11/why-dont-we-know-where-all-the-trains-are/415152/

Design goal #1: Two trains must never touch

Block signaling

CBTC Communications-based

train control

Lesson #1: No model easier and quicker

Lesson #2: Models answer questions

Configuration management:

Manage infrastructure inputs over time and at scale

ftp: /var/ftp/vsftpd.conf -> server1 install -o remove /etc ; cmdspecial “service vsftpd reload”

Containers are closures

“We believe that the complexities in a complex system are often

illusory. Many are the result of less than thoughtful design, or at least, design not motivated by a goal of

decreasing complexity…”

Couch et.al.

Orchestration:

Make coordinated changes to more than one machine*

Conclusions

No model often easiest and simplest

Models answer questions (better ask the right ones)

We need to change our models (but it’s an evolution)