chapter three

Question 1

what did we need to make the cloud a real thing?

Answer 1

based on ideas and experiences in parrallel and distributed systems accumliated in mant years of research.

Question 2

what made parallel and distributed computing a real thing?

Answer 2

major advances in many computer science areas like algorithms, programming languages, computer architecture, internet connections, and solid-state technologies.

Question 3

why do we need to use parallel and distributed computing?

Answer 3

because applications do run concurrently and require a reliable and an in-order delivery of messages

Question 4

what is the most important thing needed in parallel and distributed computing?

Answer 4

the fabric “internet connection” for “communications”.

Question 5

why do we need concurrency in parallel and distributed computing?

Answer 5

because the cloud applications are data-intensive, and use a number of instances that run concurrently

Question 6

what to do in advance to deal with a system failure?

Answer 6

Checkpoint-restart procedures are used, as many cloud computations run for extended periods of time on multiple servers.

Question 7

How Parallel processing and distributed computing allow us to solve large
problems?

Answer 7

by splitting them into smaller ones and solving them
concurrently.

Question 8

what does parallel processing refer to?

Answer 8

concurrent execution on a system with a large number of processors.

Question 9

what does Distributed computing mean?

Answer 9

concurrent execution on multiple systems, often located at different sites.

Question 10

what is or how does Coarse-grained parallelism work?

Answer 10

large blocks of code executed before concurrent threads communicate.

Question 11

what is or how does Fine-grained parallelism work?

Answer 11

short bursts of computations alternate with relatively long periods when a thread waits for messages from other threads.

Question 12

what is Pipelining?

Answer 12

splitting an instruction into a sequence of steps that can be executed concurrently by different circuitry on the chip.

Question 13

what is CISC?

Answer 13

Complex Instruction Set Computer
a much larger number of pipeline stages, e.g., an Intel Pentium 4
processor has a 35-stage pipeline

Question 14

what is RISC?

Answer 14

Reduced Instruction Set Computing architecture consists of five stages

Question 15

what are Hazards?

Answer 15

Instances when unchecked pipelining would produce incorrect results.

Question 16

explain data hazard RAW

Answer 16

read after write

Question 17

explain data hazard WAR

Question 18

explain data hazard WAW

Question 19

The architecture of pipline should conserve what ?

Answer 19

perserve exception behaviour order and conserve instruction flow

Question 20

what is Pipeline stall

Answer 20

delay in the execution of an instruction in an instruction pipeline in order to resolve a hazard. Such stalls could drastically affect the performance.