1. SCTP Handoff for Cluster Servers
Sponsored By : Dreamz Group
External Guide : Mr. Nitin Kumbhar
Internal Guide : Prof. R. B. Ingle & Prof. Geetanjali Kale
Paresh Bafna
Amit Khanna
Zaki Mulla
PICT (Pune Institute of Computer Technology)

2. Introduction Data intensive services Why Clusters ?
E.g. Web, FTP, Multimedia
Why Clusters ?
Cost effectiveness
Scalability
Security
Optimized servers
Fault tolerance

3. SCTP in Clusters Multistreaming Multihoming Security
No multiple connection overhead
No Head-of-Line Blocking problem
Better response times
Multihoming
Partial network failure tolerance
Security

4. Current Scenario Proxy Clients Gateways Server Cluster Server 1
Server n
Internet
Proxy
Clients
Gateways
Server Cluster
Request
Response

5. Problems In The Existing Scenario
Context Switch + Data Copying
Context Switch + Data Copying
User
Kernel
Client
Server
Proxy

6. Problems In The Existing Scenario
3 Data Buffers
Data copying between kernel
and user-space buffers
User-kernel context switches
Interrupts
Bottleneck at proxy
Reduced scalability
Number of Clients X

7. Proposed Mechanism Client Server 1 Server 2 Proxy Server n Gateways
Internet
Proxy
Server n
Gateways
Server Cluster
Request
Response

8. Handoff Mechanism Split stack Client Proxy Server
Synchronization information -
IP, port, vtag,
Seq No…
Client
Proxy
Server
Content Aware Dispatcher
Load Balancer
Sync
Req
Data

9. Architecture Server Cluster Proxy Server To client Handoff Server
Web
User
Handoff Server
Kernel
Resource Utilization Daemon
Load Balancer
Handoff Client
Plug-in
SCTP Hand Off Layer
Content- aware Dispatcher
Proxy Server
Request or Acknowledgement packet
Response packet

10. Implementation overview
Proxy
Content-aware-dispatcher
Rule based
Load balancer
Create an association with each server
Handoff client
Hook SCTP packets from clients
Maintain Sync info
Send Sync info to server
Forward packet to server

11. Implementation overview (contd)
Server
Resource utilization daemon
Free Memory, CPU idle time, Live associations
Handoff server
Extract and interpret sync info
Replicate half stack on server

12. Marketability No client side changes needed Generic … Web portal
Web server
FTP
Multimedia server
Centralized administration

13. Demo Setup Client Proxy Server IP addr – 10.10.4.227
H/W addr – 00:50:BA:3D:92:1C
Proxy
IP –
H/W addr – 00:50:BA:3D:92:22
Server
IP –
H/W addr – 00:50:BA:3E:96:F7

14. Implementation Features
Generic
Servers vs Services
Includes load balancing and content-aware dispatching
Completely inside kernel

15. Performance Current Scenario Proposed mechanism Improvement
Data Buffers 3 1
66.6%
Context switches 2
100%
Stack traversals 6 4
33.3%
Interrupts
CPU utilization at proxy
Response/ request ratio
Improvement 1
50% 2
66.6% 3
75%

16. Thank You !