95-843 Service Oriented
Architecture
Cloud Computing and SOA
Notes adapted from “A View of Cloud Computing” , Armbrust,
and others -UC Berkeley Reliable, Adaptive, Distributed
Systems Laboratory
95-843 SOA
Master of Information System
Management
1
Adapted from “A View of Cloud Computing”
UC Berkeley
Cloud Computing
From “A View of Cloud Computing” , Armbrust, and
others -UC Berkeley Reliable, Adaptive, Distributed
Systems Laboratory
95-843 SOA
Master of Information System
Management
2
Adapted from “A View of Cloud Computing”
UC Berkeley
Suppose you have an
innovative idea…
• You need a large capital outlay in
hardware.
• You need talented humans to operate
and maintain the system.
• There is an over provisioning risk – the
new system may not be as popular as
you hoped.
• There is an under provisioning risk missing and losing potential users.
• Cloud computing allows you to start
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of Information
System
smallMaster
and
grow
as
needed.
Management
Adapted from “A View of Cloud Computing”
UC Berkeley
Over or UnderProvisioning
95-843 SOA
Master of Information System
Management
4
Adapted from “A View of Cloud Computing”
UC Berkeley
Over or UnderProvisioning
Shaded area is unused capability.
95-843 SOA
Master of Information System
Management
Less and
less
demand.
Shaded area represents
requests not served.
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Adapted from “A View of Cloud Computing”
UC Berkeley
Real world estimates
• Average server utilization is 5% to
20%.
• Peak workload exceeds the average by
factors of 2 to 10.
• Users provision for the peak.
• Peak loads may occur based on the
time of day or based on other factors
(e.g. photo sharing after the holidays,
drop/add within two weeks of start of
term, etc.)
95-843 SOA
Master of Information System
MasterManagement
of Information System
Adapted from “A View of Cloud Computing”
UC Berkeley
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Or, suppose you have as
large batch-oriented task?
• How do we benefit from using a
cloud?
• 1000 servers for one hour costs
not more than 1 server for 1000
hours.
• This degree of elasticity may be
unprecedented in the history of IT.
95-843 SOA
Master of Information System
Management
7
Adapted from “A View of Cloud Computing”
UC Berkeley
Three new aspects
• The illusion of infinite computing
resources on demand (no far
ahead provisioning concerns)
• The elimination of up front
commitment by cloud users (start
small and grow)
• Pay for resources on a short term
basis as needed (reward
conservation)
95-843 SOA
Master of Information System
Management
8
Adapted from “A View of Cloud Computing”
UC Berkeley
Key Enablers
• Construction and operation of
extremely large-scale commoditycomputer datacenters at low cost
locations
• Statistical multiplexing to increase
utilization (to each according to his
needs) – varies over time – this
differs from traditional hosting
• Virtualization of computation,
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storage, and communication
95-843 SOA
Master of Information System
Management
Adapted from “A View of Cloud Computing”
UC Berkeley
Three Examples
• AppEngine (Google) Build scalable web
applications fast. Not for general purpose
computing.
• Azure (Microsoft) Use .NET and .NET
libraries as needed. General purpose
computing on a Microsoft platform.
• EC2 (Amazon) Elastic Compute Cloud
(Choose OS and the entire software stack.
General purpose computing
95-843 SOA
Master of Information System
Management
10
Adapted from “A View of Cloud Computing”
UC Berkeley
Three Examples
• AppEngine (Google) Least flexible
Application domain-specific platform
Automatic scaling and high availability
Proprietary megastore for data storage
• Azure (Microsoft)
Moderately Flexible
Language independent software
development platform
• EC2 (Amazon)
Highly Flexible
Hardware virtual machine
You build from the kernel upward
95-843 SOA
Master of Information System
Management
11
Adapted from “A View of Cloud Computing”
UC Berkeley
Top 10 Obstacles To Cloud
Computing
1.Business continuity and service
availability
Will the cloud provider remain in
business over the long haul?
Can we prevent a single point of
failure by using more than one
provider?
95-843 SOA
Master of Information System
Management
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Adapted from “A View of Cloud Computing”
UC Berkeley
Top 10 Obstacles To Cloud
Computing
2. Data Lock-in
Cloud storage is essentially
proprietary.
SaaS developers cannot easily extract
their data and place it on multiple
clouds.
One solution would be to
standardize data API’s.
95-843 SOA
Master of Information System
Management
13
Adapted from “A View of Cloud Computing”
UC Berkeley
Top 10 Obstacles To Cloud
Computing
3. Data Confidentiality/Auditability
Security is one of the most
often-cited objections to cloud
computing.
The authors
this is
Think HIPAA regulations and believe
no more
difficult than
in traditional
Sarbanes-Oxley
datacenters.
This is an old and difficult
problem but, in the cloud, more
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parties are involved.
95-843 SOA
Master of Information System
Management
Adapted from “A View of Cloud Computing”
UC Berkeley
Top 10 Obstacles To Cloud
Computing
4. Data transfer bottlenecks
At $100 to $150 per terabyte transferred, costs may quickly
add up. Shipping disks may be cheaper.
In 2010, the Library of Congress claims to hold 235 terabytes.
Wikipedia holds about 5.87 terabytes.
Watson, of “Jeopardy” fame, has 16 terabytes of RAM.
One terabyte is about 1012 bytes.
95-843 SOA
Master of Information System
Management
15
Adapted from “A View of Cloud Computing”
UC Berkeley
Top 10 Obstacles To Cloud
Computing
5. Performance unpredictability
Multiple virtual machines can share CPU’s and main memory
very well in cloud computing. Network and disk I/O
sharing is less predictable.
Virtual machines are not new. IBM developed much of this in
the 1980’s.
Flash memory preserves information when powered off
like mechanical hard disks. It is much faster to access
and its use may reduce I/O interference.
95-843 SOA
Master of Information System
Management
16
Adapted from “A View of Cloud Computing”
UC Berkeley
Top 10 Obstacles To Cloud
Computing
6. Scalable storage
An open research question is to create a storage system
that would not only meet existing programmer expectations
in regard to durability, high availability, and the ability to
manage and query data but combine them with the cloud
advantages of scaling arbitrarily up and down on demand.
AWS uses Amazon Elastic Block Store (EBS) and SimpleDB
Azure uses SQL Data Services and Azure Storage Service
AppEngine uses Megastore/BigTable
Many open source NO(Not Only)SQL Projects
95-843 SOA
Master of Information System
Management
17
Adapted from “A View of Cloud Computing”
UC Berkeley
Top 10 Obstacles To Cloud
Computing
7. Bugs in large scale distributed
systems
News on April 25, 2011:
Amazon said it has completed its recovery efforts and
a tiny percentage of data lost won't be fully restored.
"We're in the process of contacting these customers,"
Amazon said Monday afternoon on its Web site.
Amazon said it is "digging deeply" into the root causes
behind last week's shutdown and will provide a
"detailed post mortem" in the future.
95-843 SOA
Master of Information System
Management
18
Adapted from “A View of Cloud Computing”
UC Berkeley
Top 10 Obstacles To Cloud
Computing
8. Scaling quickly
Pay as you go applies to storage and network bandwidth.
Simply count byes used.
Google App Engine automatically scales based on load
increases and decreases.
AWS charges by the hour for the number of instances you
occupy – even if your machine is idle.
The challenge is to scale fast (up and down) to save money
without violating SLA’s.
95-843 SOA
Master of Information System
Management
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Adapted from “A View of Cloud Computing”
UC Berkeley
Top 10 Obstacles To Cloud
Computing
9. Reputation fate sharing
One bad apple spoils the bunch.
EC2 IP addresses have been
blacklisted by spam prevention services – blocking some good
guys from sending email.
The FBI raided a Dallas data center because a company whose
services were hosted there was under investigation. Many
“innocent bystanders” were down for days – and some went
out of business.
95-843 SOA
Master of Information System
Management
20
Adapted from “A View of Cloud Computing”
UC Berkeley
Top 10 Obstacles To Cloud
Computing
10. Software licensing
Current practice is to restrict the computer on which the
software can run. The software is purchased along with a
maintenance fee. This is not the pay-as-you go model.
Microsoft and IBM are now offering pay-as-you go pricing.
In 2011, IBM charges $6.39 per hour for WebSphere with
Lotus Web Content Management running on EC2.
95-843 SOA
Master of Information System
Management
21
Adapted from “A View of Cloud Computing”
UC Berkeley
SOA and Cloud Computing
“While you can certainly leverage a cloud without practicing SOA,
and you can leverage SOA without leveraging cloud computing,
the real value of cloud computing is the ability to use services,
data, and processes that can exist outside of the firewall…”
From “Cloud Computing and SOA Convergence in your Enterprise”
by David S. Linthicum
95-843 SOA
Master of Information System
Management
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Adapted from “A View of Cloud Computing”
UC Berkeley