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Service Oriented Architecture. Cloud Computing. From “ A View of Cloud Computing ” , Armbrust, and others -UC Berkeley Reliable, Adaptive, Distributed Systems Laboratory. Suppose you have an innovative idea… . You need a large capital outlay in hardware.
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Cloud Computing From “A View of Cloud Computing” , Armbrust, and others -UC Berkeley Reliable, Adaptive, Distributed Systems Laboratory Master of Information System Management
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. Master of Information System Management
Over or Under-Provisioning Master of Information System Management
Over or Under-Provisioning Less and less demand. Shaded area represents requests not served. Shaded area is unused capability. 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.) Master of Information System Management 6 Master of Information System Management
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. Master of Information System Management
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) Master of Information System Management
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 Master of Information System Management
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 Master of Information System Management
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 Master of Information System Management
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? Master of Information System Management
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. Master of Information System Management
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. The authors believe this is no more difficult than in traditional datacenters. Master of Information System Management
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. Master of Information System Management
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. Master of Information System Management
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 Master of Information System Management
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. Master of Information System Management
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. Master of Information System Management
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. Master of Information System Management
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. Master of Information System Management
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 Master of Information System Management