P2L5

Question 1

Performance metrics are

Answer 1

measurable and quantifiable property
of the system we’re interested in
that can be used to evaluate the system behavior

Question 2

Examples of performance metrics

Answer 2

execution time, throughput, request rate, CPU utilization, platform efficiency, wait time, performance / $, performance / W, percentage of SLA violations, avg resource usage

Question 3

Event-driven model

Answer 3

single address space
single process
single thread of control
dispatcher == state machine

Question 4

MP and MT vs Event Driven

Answer 4

MP and MT 1 request per exec context

Event Driven many requests interleaved n an execution context

Question 5

Most efficient way to wait for input on fd

Answer 5

epoll more efficient than select and poll

Question 6

Helpers

Answer 6

designated for blocking I/O operations
pipe / socket based comm w/ event dispatcher
helper blocks, but main event loop will not

Question 7

AMPED

Answer 7

Asymmetric Multi-Process Event Driven Model

Question 8

AMTED

Answer 8

Asymmetric Multi-Thread Event Driven Model

Question 9

AMPED/AMTED

Answer 9

smaller footprint than regular process/thread

Question 10

Flash

Answer 10

AMPED with asymmetric helper processes

Question 11

Apache

Answer 11

Combo of MP / MT

Question 12

Experimental Methodology

Answer 12

Define comparison points
Define inputs
Define metrics

Question 13

When data is in cache

Answer 13

SPED&raquo_space; AMPED Flash
- unnecessary test for memory presence
SPED and AMPED Flash&raquo_space; MT/MP
- sync and context switching overhead

Question 14

With disk-bound workload

Answer 14

AMPED Flash&raquo_space; SPED
- SPED blocks b/c no async I/O
AMPED Flash&raquo_space; MP/MT
- more memory efficient and less context switching

Question 15

Relevant experiments

Answer 15

statements about a solution, that others believe in and care for