1. Content Dissemination Systems Including Streaming Systems
Lauren Bay, William Barras, Nigel Wallingford
CS455: Introduction to Distributed Systems
Computer Science Department, Colorado State University

2. Why is this problem important?
Streaming content
Netflix
Pandora/Spotify
Torrents
Linux .iso files
Software packages
Media
Publish-Subscribe
News

3. Problem Characterization
Content Dissemination
Distribution of content over a network
Multiple architectures that can be used to distribute content
Main Architectures
Client-server
Peer-to-peer
Specific Models
Publish-subscribe

4. Trade-off space for solutions in this area
Pros
Cons
Peer-to-Peer
Inexpensive
Highly redundant
Scalable
Client-Server
Content replication
Data security
Ability to regulate traffic
Publish-Subscribe
Isolated responsibilities
Peer-to-Peer
Insecure
Client-Server
No redundancy
Publish-Subscribe
Transmission problems may go unnoticed

5. Dominant approaches to the problem (1)
Peer-to-Peer
More failure resilient
Avoids chokepoints
Freeloaders can reduce network performance
Client-Server
Don’t have to rely on other users
Can be maintained by one entity

6. Dominant approaches to the problem (2)
Peer-to-Peer
DHTs
Gossip based networks
LiFTing
Client-Server
Web browsing
Netflix

7. Insights Gleaned Publish-Subscribe Model
Helps solve many of the inherent deficiencies of traditional client-server approach
Can be paired with client-server or peer-to-peer architecture, ideally for situations where data transmission/reception is time or space decoupled
Improving efficiency of existing systems
Retrofitting proven systems to make them more suited to modern environments
Improving efficiency of low-level protocols
IP is an aging technology
New protocols, like NDN promise better data routing and enhanced security

8. What the problem space in the future would look like
Migration from client-server to peer-to-peer
Content size increasing
Online population increasing
Changes in content distribution laws
Impossible to prevent the illegal distribution of content
Disappearance of physical media
More convenient and economical to download content than to purchase physical media

9. Trade-off space and solutions in the future
Named Data Networking
Replacement for IP
Replaces addresses with data names
Network routes requests to host with the specified data
Very unlikely that everyone will be convinced to switch to a new low level protocol

10. Questions?