The History of Pets vs. Cattle

Randy BiasVice President

September 30, 2016OpenStack Days Seattle

@randybias

… & Using It Properly

Once upon a time …

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Cloud was Hard to Explain

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It Wasn’t Really About Buying Online Services

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2012

How to explain … ???

It’s got to be simple. Dead simple.

I Went Looking for Inspiration

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Bill Baker had a genius explanationfor scale-out vs. scale-up

So I, um … Appropriated It

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Randy Bias

And a Meme was Born…

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How to Explain Why Cloud is Different

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Hint: it’s about uniqueness

“”

In the old way of doing things, we treat our servers like pets. For example,

‘Frodo’ the mail server. If Frodo goes down, it’s all hands on deck. The CEO can’t get his email and it’s the end of

the world.

In the new way, servers are numbered, like cattle in a herd. For example,

www001 to www100. When one server goes down, it’s taken out back, shot,

and replaced on the line.

— Randy Bias (many hundreds of times from 2012-2016)9

The Old Way: Assembly Line IT

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“Mode 1”, “The Second Platform”, “Legacy”

GUI Driven Ticket Based Hand Crafted

Reserved Scale-Up

Smart Hardware Proprietary

“Waterfall Ops” . . .

Each Server Built This Way is A “Pet”

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“I love you!”

• Unique & indispensable

• Hand fed, hand-crafted

• Examples:

–mainframes

–HA pairs (LB, firewall, etc.)

–master/slave databases

• A “herd” of cattle is not 2 servers

The New Way: Robotics Factory IT

“Mode 2”, “Third Platform”, “Cloud-Native”

API Driven Self Service Automated On Demand Scale-Out

Smart Apps Open Source Agile DevOps

. . .

Every Server is Just Another Part of the Herd

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“Lunch!”

• “A herd” is just many homogeneous servers

• 100% automated & designed to fail

• Load balanced & multi-master

• LB: svc discovery, DNS, H/W LB

• Examples: - web server arrays - multi-master data stores (Cassandra) - Hadoop clusters

Pets vs Cattle

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GUI Driven Ticket Based Hand Crafted

Reserved Scale-Up

Smart Hardware Proprietary

“Waterfall Ops” . . .

API Driven Self Service Automated On Demand Scale-Out

Smart Apps Open Source Agile DevOps

. . .

Disposable, One of the

HerdUnique and

Indispensable

Our Brave New World

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• Failures happen … always

• Everything must fail without an impact: server components, servers, racks, datacenters … everything

• And most importantly, apps must detect and route around these failures

The Fundamental Difference

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The Old Way(inelastic)

The New Way(elastic)

99.9%Applications

99.999%Infrastructure

($$$$)

99.999% Applications

99.5% Infrastructure

($)

Responsibility

Shift

Extending the Meme … Muddies the Water

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An Example: Kubernetes “Pet Sets”

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Stateful Applications supported by “Pet Sets”

• Cassandra

• Kafka

• MongoDB

These are Cattle-architected data store systems

Source: K8s Blog: Stateful Applications in Containers!? Kubernetes 1.3 Says "Yes!”

The World’s Biggest Stateful System is …

21Cattle … All the Way Down

Getting Value from “Pets vs Cattle”

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Respect the Meme

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See Also:

• http://tinyurl.com/history-pets-cattle

• http://www.slideshare.net/randybias/pets-vs-cattle-the-elastic-cloud-story

• http://www.lauradhamilton.com/servers-pets-versus-cattle

• http://www.theregister.co.uk/2013/03/18/servers_pets_or_cattle_cern/

• http://www.slideshare.net/randybias/architectures-for-open-and-scalable-clouds