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Ensuring Cloud Native Success: The Legacy Journey
2
The Three “Journeys”
Greenfield
• Brand new
• Little integration with
existing IT
• Rarely “mission critical”
Legacy
• Makes all the money
• Fragile, change is high
risk
• Can consume all
corporate attention
Transformation
• Targets entire
organization
• Benefits of scale
• “Culture” change
drives success
Watch ON
Demand
Dec 15th, 10am PT/
12pm CT/ 1pm ETWatch ON
Demand
3
@cote – Director, Technical Marketing
at Pivotal for Pivotal Cloud Foundry
Former industry analyst at 451
Research and RedMonk
Corporate Strategy & M&A at Dell
Software developer
Podcasts: cote.io/podcasts
FierceDevOps columnist
More: http://cote.io or [email protected]
Hello!
44
Why?
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The goal is not “cloud,” rather shifting to using software as your core enabler of business
Release weekly, if not daily
Software continually updated to
match evolving business
models
IT is the enabler of growth
Software Defined Business
For the business “oh crap” motivations, see “The 3 Horsemen of the Digital Apocalypse” and the first part of of my DevOpsDays talk.
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Legacy
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“Legacy” is usually existing software that’s odious to change
“Makes all the money” so
it’s mission critical
Lacks good testing, so it’s
risky to change, fragile
Often built with “pre-cloud”
technologies
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Actively manage your portfolio or it will manage you
Source: “A Value Framework that Works for Transforming Your Application Portfolio,” June, 2015. See more commentary on dealing with
legacy in “Dealing With The Stuff That Makes All The Money.”
Key transformation effects:
• Reduce costs to run “legacy”
systems
• Free resources (time, money,
attention) for “innovation”
• Waste elimination: cloud platform
automates infrastructure
management & “paperwork”
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Filter projects
Projects with low business value – make it worth your time
The business case hasn’t run out yet – don’t write things off
Agile Resistant Projects:1. Tight integration and
coordination across division lines
2. Company-wide and/or industry standards can not easily be changed or ignore
3. Technology ill-suited for cloud native, or not “modernized” at all
See “Migrating the Monolith,” Rohit Kelapure, Nov 2015 for more technical details.
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Approaches for the left-overs
Virtualize to control costs
and maximize management
API gateways combined
with the strangler pattern
Rewriting to be cloud native
See “Migrating the Monolith,” Rohit Kelapure, Nov 2015 for more technical details.
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Filtering for technology fit
Generally good:
Stateless
Horizontal scaling
Well packaged Java applications
Applications that are configured at runtime
RESTful services approach
Generally bad:
Reliance on local storage
Manages complex background processes
Uses proprietary APIs, hardware
Manual startup/shutdown
Long lived, fast connections
Sources: "Pivotal Cloud Foundry Application Migration Selection Criteria," Josh Kruck & Abby Kearns, Q1 2015; "How Do I Migrate
Applications to Pivotal Cloud Foundry?" Josh Kruck, June 2015; “Case Study: Refactoring A Monolith Into A Cloud Native App” series,
Jared Gordon, Aug 2015.
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Get strict with testing
The Legacy Code
Dilemma
When we change code,
we should have tests in
place. To put tests in
place, we often have to
change code.
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Strangle old code, perhaps replacing…one day
Sources: pattern write-up from Martin Fowler, small case studies. Picture from wikipedia’s Ficus aurea page, diagram from Branch by
Abstraction write-up, 2011.
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Review boards and other “helpful” processes
Automate the helpful processes
Establish trust with review boards – small wins, etc.
Expose process bottlenecks
Your process is as important as the process, change it accordingly
Sources: clip art from geralt.
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If all this sounds hard, let that be a reminder of how important architectural and process hygiene is – start doing it right!
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What’s next?
Greenfield
• Brand new
• Little integration with
existing IT
• Rarely “mission critical”
Legacy
• Makes all the money
• Fragile, change is high
risk
• Can consume all
corporate attention
Transformation
• Targets entire
organization
• Benefits of scale
• “Culture” change
drives success
Watch ON
Demand
Dec 1st, 10am PT/ 12pm
CT/ 1pm ET
Dec 15th, 10am PT/
12pm CT/ 1pm ET
