1. Cloud Computing:
Bringing the Dark Side of
Enterprise Apps into the
Light
Jason Bloomberg, President
ZapThink, A Dovel Technologies Company
Copyright © 2012, ZapThink, a Dovel Technologies Company
About Jason Bloomberg
• President of ZapThink, a Dovel Technologies Company
– One of the original Managing Partners of ZapThink LLC
– Acquired by Dovel Technologies in August 2011
• Global thought leader in the areas of Cloud Computing,
EA, & SOA
• Created the Licensed ZapThink Architect
(LZA) SOA course & associated credential
• Run LZA course & Cloud Computing for
Architects course around the world
• Columnist on US Government IT for CIO Magazine and
blogger for DevX
• Formerly at IDC, USWeb/CKS (later marchFIRST) and
WaveBend Solutions (now Hitachi Consulting) 2
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2. The Dark Side: Enterprise IT
• Monolithic apps
• Partition
intolerant
• ACID
transactionality
• High cost
• Single point of
control
Copyright © 2012, ZapThink, a Dovel Technologies Company
Elastic Thinking
• Each tier has indeterminate
number of nodes
• Number of nodes in each
tier may change
unexpectedly
• Nodes may fail at random
The Web works this way,
and so can your app!
Copyright © 2012, ZapThink, a Dovel Technologies Company
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3. The Challenge of Fault
Tolerance
• The old way
– Mirroring
– RAID disks
– High availability
• The new way
– Commodity hardware
– Automated reprovisioning after failure
(“bootstrapping”)
– Stateless processing
– Basic availability
Copyright © 2012, ZapThink, a Dovel Technologies Company
The Challenge of Scalability
• The old way: vertical
scalability (scale up)
– Few expensive servers
– Add resources to individual
boxes
– Best for monolithic apps
• The new way: horizontal
scalability (scale out)
– Many commodity servers
– Must architect accordingly
Copyright © 2012, ZapThink, a Dovel Technologies Company
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4. The Challenge of Control
• The old way:
– Centrally managed apps
– Expensive licenses
– Expensive maintenance contracts
– Difficult upgrades
– Even more difficult customization
• The new way:
– BYOD
– App store model for software
– Distributed hypermedia apps
Copyright © 2012, ZapThink, a Dovel Technologies Company
The Challenge of Mobility
Phone or computer?
UI endpoint or Cloud resource?
Communication tool or remote sensor?
The Internet of Things Changes Everything!
Copyright © 2012, ZapThink, a Dovel Technologies Company
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5. The Challenge of Clustering
Virtual Server Single System
Physical Image
Physical
Physical
Physical
Server
Server
Server
Server
High Availability
Clusters
Clustering
Grid
Physical Server
Virtualization Computing
Virtual
Virtual
Virtual
Virtual
Server
Server
Server
Server
Cloud
Computing Copyright © 2012, ZapThink, a Dovel Technologies Company
Challenge of Multitenancy
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6. Partition Tolerance
• A distributed system is partition tolerant if it
will continue working even in the case of a
partial network failure
• Bits and pieces can fail or otherwise stop
communicating with the other bits and pieces,
and the overall system will continue to
function
Cloud
environments are
inherently
partition tolerant
Copyright © 2012, ZapThink, a Dovel Technologies Company
CAP Theorem
No
distributed
computing High
system can Consistency
Availability
guarantee Availability
immediate
consistency,
basic
availability,
and partition
tolerance at
Partition
the same Tolerance
time
Copyright © 2012, ZapThink, a Dovel Technologies Company
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7. Basic Availability
• Guarantee that every
request receives a
response about
whether it was
successful or failed
• The entire application
will keep working even
if one or more nodes
fail
Copyright © 2012, ZapThink, a Dovel Technologies Company
Eventual Consistency
• Immediate consistency
– All nodes see the same
data at the same time
– All data are always
consistent
• Eventual consistency
– Data will be consistent
after a set amount of time
passes since an update
– Up to you how long
Copyright © 2012, ZapThink, a Dovel Technologies Company
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8. BASE instead of ACID
• Basic Availability
– Supports partial failures without leading to a
total system failure
• Soft-state
– Any change in state must be maintained
through periodic refreshment
• Eventual consistency
– It’s OK to use stale data some
of the time
Copyright © 2012, ZapThink, a Dovel Technologies Company
The Challenge of State
Where should you maintain state information?
• On the Cloud instance?
– Not fault tolerant
– Limits performance
• At the persistence tier?
– Often doesn’t scale
• On the client?
– Requires architectural approach that enables
hypermedia to be the engine of application state
Copyright © 2012, ZapThink, a Dovel Technologies Company
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9. The Secret to Transferring App
State to the Client
Hypermedia should be
the engine of application
state!
Copyright © 2012, ZapThink, a Dovel Technologies Company
HATEOAS????
• One of REST’s four
architectural constraints
• The constraint RESTafarians
struggle most with
BUT…
• The MOST IMPORTANT
one… since hypermedia
applications are the
POINT of REST!
Copyright © 2012, ZapThink, a Dovel Technologies Company
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10. The Challenge of Architecture
• The old way: Web
Services-Based SOA
– Middleware-centric
– Complex governance
– Difficult
• The new way: REST-Based
SOA
– Hypermedia-centric
– Lightweight
BUT… most RESTafarians don’t get it!
Copyright © 2012, ZapThink, a Dovel Technologies Company
Hypermedia,
SOA & the Cloud
• Cloud Computing driving
the Enterprise to the world
of Web scale
• Hypermedia core to the
Web and also essential
for elastic, stateful apps in
the Cloud
• REST-Based SOA: Can
hypermedia replace your
ESB?
Copyright © 2012, ZapThink, a Dovel Technologies Company
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11. What About Enterprise App
Vendors?
Shared hardware Public Cloud
multitenancy FUD
Tightly coupled Cloud-unfriendly
APIs licensing
Warmed over
middleware
Copyright © 2012, ZapThink, a Dovel Technologies Company
The Light Side: The World of
Web Scale
• Hypermedia apps • Resilient
• Partition tolerant • No single point
• BASE transactionality of control
Copyright © 2012, ZapThink, a Dovel Technologies Company
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12. Thank You!
Jason Bloomberg
President
ZapThink, a Dovel Technologies Company
jbloomberg@zapthink.com
@theebizwizard
Copyright © 2012, ZapThink, a Dovel Technologies Company
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