95-843 soa adapted from “a view of cloud computing” uc berkeley 1 master of information system...
TRANSCRIPT
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
1Master of Information System Management
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
Adapted from “A View of Cloud Computing”UC Berkeley
Cloud Computing
2Master of Information System Management
From “A View of Cloud Computing” , Armbrust, and others -UC Berkeley Reliable, Adaptive, Distributed Systems Laboratory
95-843 SOA
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 small and grow as needed.
3Master of Information System Management
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
Over or Under-Provisioning
4Master of Information System Management
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
Over or Under-Provisioning
5Master of Information System Management
Shaded area is unused capability.Shaded area representsrequests not served.
Less and less demand.
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
Master of Information System Management
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.)
6Master of Information System Management
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
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.
7Master of Information System Management
95-843 SOA
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)
8Master of Information System Management
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
Key Enablers
• Construction and operation of extremely large-scale commodity-computer 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, storage, and communication
9Master of Information System Management
95-843 SOA
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
10Master of Information System Management
95-843 SOA
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
11Master of Information System Management
95-843 SOA
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?
12Master of Information System Management
95-843 SOA
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.
13Master of Information System Management
95-843 SOA
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. Think HIPAA regulations and Sarbanes-Oxley This is an old and difficult problem but, in the cloud, more parties are involved.
14Master of Information System Management
The authorsbelieve this isno more difficult thanin traditionaldatacenters.
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
Top 10 Obstacles To Cloud Computing
4. Data transfer bottlenecks
15Master of Information System Management
At $100 to $150 per terabyte transferred, costs may quicklyadd 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
Adapted from “A View of Cloud Computing”UC Berkeley
Top 10 Obstacles To Cloud Computing
5. Performance unpredictability
16Master of Information System Management
Multiple virtual machines can share CPU’s and main memoryvery 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 offlike mechanical hard disks. It is much faster to accessand its use may reduce I/O interference.
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
Top 10 Obstacles To Cloud Computing
6. Scalable storage
17Master of Information System Management
An open research question is to create a storage systemthat would not only meet existing programmer expectationsin regard to durability, high availability, and the ability tomanage and query data but combine them with the cloudadvantages of scaling arbitrarily up and down on demand.
AWS uses Amazon Elastic Block Store (EBS) and SimpleDBAzure uses SQL Data Services and Azure Storage ServiceAppEngine uses Megastore/BigTableMany open source NO(Not Only)SQL Projects
95-843 SOA
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.
18Master of Information System Management
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
Top 10 Obstacles To Cloud Computing
8. Scaling quickly
19Master of Information System Management
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 youoccupy – even if your machine is idle.
The challenge is to scale fast (up and down) to save moneywithout violating SLA’s.
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
Top 10 Obstacles To Cloud Computing
9. Reputation fate sharing
20Master of Information System Management
One bad apple spoils the bunch.
EC2 IP addresses have beenblacklisted by spam prevention services – blocking some goodguys from sending email.
The FBI raided a Dallas data center because a company whoseservices were hosted there was under investigation. Many “innocent bystanders” were down for days – and some went out of business.
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
Top 10 Obstacles To Cloud Computing
10. Software licensing
21Master of Information System Management
Current practice is to restrict the computer on which thesoftware can run. The software is purchased along with amaintenance 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 withLotus Web Content Management running on EC2.
95-843 SOA
Adapted from “A View of Cloud Computing”UC Berkeley
SOA and Cloud Computing
22Master of Information System Management
“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