Content Distribution

Question 1

Request headers: user-agent

Answer 1

the software (browser) used to make the request

Question 2

Response headers: expires

Answer 2

how long the content can be cached

Question 3

Ways that clients can be directed to a cache

Answer 3

1. Browser configuration

2. Server directed. Uses a redirect 3xx to point to a CDN or cache.

Question 4

CDN: basic goal

Answer 4

Replicate content on many servers

Question 5

CDN: what metric to select best server?

Answer 5

Lowest latency

Question 6

Content Routing: Naming-based Redirection (DNS)

Answer 6

1. Provides fine-grained control

2. Fast

Question 7

Bit Torrent: Choking

Answer 7

Refusal to upload to a particular peer

If a peer can’t upload, don’t allow them to download.

Question 8

Chord: what is it?

Answer 8

1. Distributed Hash Table

2. Lookup service (anything that is basically key/value)

Question 9

Consistent Hashing: what is it for?

Answer 9

1. key/values are distributed along the entire system

Question 10

Consistent Hashing: where are keys stored?

Answer 10

They are stored in the successor node.

In the lecture, this was the “ring”