Bob Vavra Unisys

1
Components and Web Services Considered
Harmful Inhibit Quality of Service

• Bob VavraUnisys

2
What do we do in handcrafted TP systems that
isnt available commercially?

• Optimization of a deployed TP system
• Optimize the non-functional attributes
• Performance, capacity, availability, durability,
  recoverability, maintainability,
• Continuing optimization by dedicated team
• Separate from development projects

3
Reusable Components and Web Services

• Have visible well-defined functional
  characteristics
• Interface definition, transaction semantics, and
  security
• Have hidden implementations
• Hidden non-functional attributes

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Non-functional attributes are important
5
Expand Definitions of Component and Web Services

• WSDL should include non-functional attributes of
  the implementation
• Useful to application architects, designers, and
  optimizers
• Useful to component suppliers
• Reinforces the notion that implementation quality
  does matter
• Some research underway on QoS for components,
  e.g., in the real-time community