Enterprise Level Computing

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Enterprise Level Computing

• Lecture 1
• An Introduction to the Module
• Dave Elliman

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You are IT manager of a large retail company.

• What is computing used for in the business?
• How does this environment differ from a working
  on your desk-top PC or laptop?
• What keeps you awake at night?

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Main areas where computers are essential

• Sales (tills are computer terminals)
• Stock Control (connected to tills)
• Bookkeeping and payroll
• Ecommerce sales
• Communications with banks suppliers
• Company intranet and email

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A Different Emphasis?

• Highly distributed
• Reliability - up-time, bug free,
• Integrity - no loss of data
• Robustness (response to failure)
• Security
• Response

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What keeps you awake?

• Hardware failure and loss of data
• Web response slowing to a standstill
• Hackers or competitors breaking our security
• Denial of service attacks crippling our response
• Catastrophic bugs in the software

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How can you stop worrying?

• The key is redundancy.
• Why use one computer when many will do?
• Primary and secondary servers
• Clusters of processors
• Multi-tiered architectures (middleware)
• Server farms

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Loss of Data Security

• Redundant disk solution (RAID)
• Database with automatic back-up often
  continuous best across network sometimes.
• Central database can be fairly secure.
• Use certificates and encryption (but this is for
  SEC not ELC)

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BUT. Isnt that hard to code?

• YES very hard lots of classic computer science
  nasties deadly embrace, data over-writing etc,
  dependent transactions to be rolled back
• TOO HARD so use a well tried solution. At least
  three ways one might go.

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The Three Paths

• Java Enterprise
• Microsoft .NET
• Open source
• In ELC we will look at each of these.
• Which is best?
• All depends Personally I think .NET is a well
  designed solution but you need some money to
  spend.

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Reasons for Taking G53ELC

• Because it is highly vocational and should give
  you interview material and sought-after skills
  for your CV to help you get a top job
• Because it will explain several ways in which you
  could make a lot of money.

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What Is the Point of G53ELC cntd

• To give you a useful Cookbook of techniques
• To help you understand the problems of
  programming in a real commercial environment

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What Form Will the Lectures Take?

• We will look at several key problems and produce
  solutions in the lectures
• A mixture of explanation and demonstrations
  (which may not always work first time)

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What Do You Expect Me to Know Already?

• I expect you to have a working knowledge of the
  Java programming language
• I expect you to have an understanding of
  relational databases, normalisation and SQL
• I expect you to know something about object
  oriented systems design

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What Do You Expect Me to Know Already? cntd

• I expect you to have some understanding of
  communications networks and protocols
• I expect you to understand HTML and have some
  familiarity with web page design

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Themes E-commerce

• How does one construct and host a commercial web
  site?
• What are the business constraints?
• How can I accept credit/debit cards for payment?
• How can I attract visitors to my site?

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Server-side Technology Compare Contrast

• Open source non-Java technology
• PHP/Apache/MysSQL/Linux
• Java2 Enterprise Technology
• - Servlets/JavaBeans/Tomcat
• Microsoft COM and .NET technology
• DCOM, IIS/C/ASP.NET/SQL Server 2000

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Themes Real-life Issues

• Performance
• Availability
• Reliability
• Scalability
• Security
• Multi-tier Implementations

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Specific Topics That Will Be Covered

• Database queries in SQL
• Client-server computing
• Java Enterprise computing
• The .NET architecture
• Web services client server
• Middleware
• An Ecommerce web site

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Specific Topics That Will Be Covered Continued

• Accessing databases with JDBC and ODBC
• XML and its role in enterprise computing
• Naming and Directory Services
• Application Servers, ORBS etc
• Enterprise Java Beans

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How Will the Module Be Assessed?

• There will be a coursework assessment (30)
• Build a web service Client
• There will be an on-line examination (70)
• You will need to turn up at a lab at an appointed
  time with identification

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What Do I Need to Know?

• Notes will be made available progressively on the
  web page
• http//cs.nott.ac.uk/dge/G53ELC/index.htm
• You may also be asked a question on anything that
  was said in a lecture or in specified notes
• The web page will have pointers to a great deal
  of material for background reading if you want to
  know more

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How Can I Find Out More Information?

• Read the Course Notes and other references from
  the web site
• The sun Java and Microsoft .NET web sites will
  provide much useful background
• Books are expensive and the course covers too
  many areas

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When Will the Lectures Be?

• Monday at 1000 LT2
• Monday at 1700 LT1

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When Will the Exam Be?

• I will let you know when I know It will be
  before the other exams. Mid-April
• I have to agree lab bookings with Kevin Hopkins

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Any Questions