Performance Orientated-Design

Question 1

What are the three categories of performance principles?

Answer 1

1. Performance control principles
2. Independent principles
3. Synergistic principles

Question 2

What are performance control principles?

Answer 2

Control performance by stating the required performance objectives to quantitively determine if software meets goals.

Question 3

What are independent principles?

Answer 3

Can be applied independently do not conflict with eachother

Question 4

What are synergistic principles?

Answer 4

Improve overall performance by allowing cooperation of processes fighting for computer resources

Question 5

What is performance objective principle?

Answer 5

Type: Performance Control Principle

Define specific, quantitative, measurable performance objectives for performance scenarios

Question 6

What is instrumenting principle?

Answer 6

Type: Instrumenting Principle

Inserting code probes at key points to enable measurement of important execution characteristics

Question 7

What is centering principle?

Answer 7

Type: Independent Principle

Identify the dominant workload functions and minimize their processing

Question 8

What is the fixing point principle?

Answer 8

Type: Independent Principle

For responsiveness, fixing should establish data connections as early as possible such that retaining the connection is cost-effective.

Question 9

What is the locality principle?

Answer 9

Type: Independent Principle

Closeness of desired actions, functions, and results to the physical resources used to produce them.

Question 10

What is the processing vs frequency principle?

Answer 10

Type: Independent Principle

Minimize the product of processing times frequency. Making a trade-off between how much times a service is called and how much work that service does on each call.

Question 11

What is the shared resource principle?

Answer 11

Type: Synergistic Principle

Share resources when possible. When excluding access is required, minimize the sum of the holding time and scheduling time.

Question 12

What is the parallel processing principle?

Answer 12

Type: Synergistic Principle

Processing time can be reduced by partitioning computation into multiple concurrent processes.

Question 13

What is real concurrency?

Answer 13

Processes execute simultaneously on different processers.

Question 14

What is apparent concurrency?

Answer 14

Processes are multiplexed on the same processors. Still need to fight for shared resources.

Question 15

What is spread-the-load principle?

Answer 15

Type: Synergistic Principle

When possible process conflicting loads at different times or different places.

Question 16

What is fixing

Answer 16

• Fixing in the sense of anchoring

Fixing connects

• the desired actions to the instructions used to complete action
• The desired result to the data to produce it

Question 17

Examples of fixing point?

Answer 17

Banker needs summary data of multiple accounts

1. Early fixing - Update the summary data as the account data arrives
2. Late fixing - Update the summary data as the banker requests

Question 18

Examples of locality principle?

Answer 18

• Multiple queries to remote database

- Regional offices vs central offices

Question 19

Examples of shared resource principle?

Answer 19

To minimize scheduling time, lock the database when being accessed (this maximizes holding time)

To minimize holding time, lock the individual records when accessing database (this maximizes scheduling time)

Question 20

Example of parallel processing principle?

Answer 20

Printing statements for large number of customers, can do this concurrently instead of sequentially.

Question 21

Example of performance objective principle?

Answer 21

ATM end-to-end interaction should take at most 1 second for the user.

Question 22

Should you be using the principles all the time?

Answer 22

False, only for critical components

Question 23

What are the performance control principles?

Answer 23

1. Performance Objective principle

2. Instrumentation Principle

Question 24

What are the independent principles

Answer 24

1. Centering Principle
2. Locality principle
3. Processing vs frequency principle
4. Fixing point principle

Question 25

What are synergistic principles

Answer 25

1. Shared resources principle
2. Spread the load principle
3. Parallel processing