The Essence of DevOps
It is not my job to build and manage
servers.
It is my job to build and maintain a
system that builds and manages servers.
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Principle of Statistical Quality Control:
Don’t blame the workers for variability
that is built into the system.
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Why DevOps?
Humans are good at strategy, but bad at
repetitive tasks
Computers are good at repetitive tasks
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Server Maintenance
• We have a wiki full of server
configurations
• Instead of a wiki, write a spec
• Write a program to build and configure
servers per the spec
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Two Ways to Scale
1. Build more web servers
2. Build a system to deploy more web
servers
for i in 1:N {
deploy_server(web_server_template, i)
}
DevOps is sometimes described as
“Infrastructure as Code.”
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Server Drift
• Identical servers will become less
identical over time
• Staging environment should match
production environment
• Redundant environment should match
primary environment
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Configuration Management
• Popular tools
- Ansible
- Chef
- Puppet
- Salt
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Advantages
• Prevent configuration drift
• Know what was changed when
• Archive previous configurations
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Softare-Defined
Networking
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Software Defined Networking (SDN) is a
DevOps approach to networking.
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It is not my job to build and manage
servers switches.
It is my job to build and maintain a
system that builds and manages
servers switches.
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Control
Plane
Data
(Forwarding)
Plane
Inside a Switch
Management
Plane
Command-‐line
interface Web
interface
CPU
ASIC
Network management
In a large organization:
- Hundreds of edge/access switches
- Dozens of core switches
How do you deploy and manage all
those devices?
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Software-Defined Networking
Software-Defined Networking (SDN)
separates the forwarding plane from the
control and management planes.
Data
(Forwarding)
Plane
A Dumb Switch
ASIC
(Flow
Table)
Commands from controller
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SDN Controller
Controller
Northbound API
Southbound Interface
(e.g. OpenFlow protocol)
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SDN: DevOps for Networks
SDN simplifies management of network
devices:
- Make changes in ONE place
- Simplify deployment
- Enforce configurations
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Other advantages
• Simpler, cheaper switches
• Mix and match switch vendors
- Avoid vendor lock-in
• Centralized traffic control
- Ability to schedule capacity for large
flows
- Avoid congested nodes/segments
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Is SDN production-ready?
YES!
• SDN is a critical part of operations for
hyperscale operators
• Used in major cloud installations
NO!
• SDN-capable switches are available
• Controllers are immature
• Need a management plane
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SDN in Orlando
The University of Central Florida is
deploying a dedicated research network
- SDN-capable
- Linked to Internet2 via Florida
LambdaRail
- Soon accepting applications for a
research network engineer position
https://www.jobswithucf.com/
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Craig Finch
[email protected]
Principal Consultant
Rootwork InfoTech LLC
http://www.rootwork.it