CS457 - System Performance Evaluation - Winter 2010


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  1. The next two lectures are based on this example.
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Lecture 4 - Abstraction from the Other Direction

A Typical System: E-Commerce Again

1. Goal(s)

A Possible System

  1. N identical servers:
  2. Users
  3. Load balancer
  4. External state (catalogue data)
  5. User state (shopping cart contents)

We have abstracted away

  1. server architecture: a server is a server
  2. communication properties: a message is a message
  3. external state: an update is an update
  4. users: sources of uncorrelated requests

2. Services

External requests

Requests to secondary servers

Requests to primary server, all the above plus

Requests to load balancer

Internal requests

Requests to secondary servers

Requests to primary servers, all the above plus

3. Metrics

Possible metrics

Always remember Goodhart's law.


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