1. DECADE Architecture Discussion
Lijiang Chen
2011/3/11

2. What are possible options?
-- In one ISP point of view

3. Inside Data Center

4. Inside Data Center
• Pros
– Easy coordinate, load balance, de-duplication….
• Cons
– Far from end-host
– Long latency?
– Middle-mile bottleneck
– what’s the distinguish from Data Center
applications?

5. Distributed in Edge

6. Distributed in Edge
• Pros
– Near end-host, law latency, load balance …
• Cons
– Difficult data de-duplication between servers
(how to efficiently utilize resources?)

7. Argument:
We should put DECADE in edge

8. Motivation Example
Every Server will keep a
copy for a period of time?!
8

9. Problem
• Coupled DECADE access with data storage
– CDN’s cache mechanism based on utilization
– DECADE’s “cache” has constraint
• Need to guarantee a basic (or temporary) available
time (1 hour, 1 day, 1 month?)
• Solution:
– Decouple DECADE access and data management

10. Decoupled DECADE access and
data management
Status Server
DECADE Server = Login Handler
or = Login Handler + Data Server
Status Handlers Data Servers
a La Index
La
b Lb Index
Lb
c
Lc Lc Index

11. Get a Data
Status Server
Status Handlers Data Servers
Login
a 1 La Index
2
La
4
3
Status Handlers

12. Remote Get without Data Transfer
Status Server
Status Handlers Data Servers
a La Index
La
2 3
b 1 Lb Index
4 Lb

13. Remote Get with Data Transfer
Status Server
Status Handlers Data Servers
a La Index
La
2 3 4
5
b 1 Lb Index
6 Lb

14. Backup

15. Architecture
Content Provider
vCDN Provider
Service Provider
ISP 2
Web Server
AS (multiple layers)
ISP 1
User DECADE
DECADE DECADE DECADE
Data
Control Msg 15

16. Discussion 1
Content Provider
vCDN Provider
Service Provider
ISP 2
x
Web Server
? x
AS (multiple layers)
ISP 1
User DECADE
DECADE DECADE DECADE
Data
Control Msg 16

17. Discussion 2
Content Provider
vCDN Provider
Service Provider
ISP 2
Web Server
AS (multiple layers)
ISP 1
User DECADE
DECADE DECADE DECADE
How do DECADE servers interact with each other?
Data
Control Msg 17