The document discusses requirements and infrastructure considerations for setting up a large-scale eSobi site. It covers clustering, load balancing, failover, and session persistence strategies. The proposed infrastructure would be highly scalable and fault-tolerant with in-memory session replication and pluggable load balancing policies. A testing infrastructure is also recommended to ensure quality and reliability of the large-scale site.

1. eSobi site Initiation
Allan Huang @ eSobi Inc.

2. Agenda
 Large-scale
Site Requirement
 Proposed Infrastructure
 Testing Infrastructure
 Conclusion

3. Large-scale Site Requirement
 Requirement


High availability
High scalability
 Considered




factors
Clustering
Load Balancing
Fail Over
Session Persistence

4. Clustering

What kind of clustering (Topology)



What kind of communication



Vertical scaling
 multiple server running on single machine
Horizontal scaling
 multiple machines in the cluster
One-to-Many Communication Using IP Multicast
Server Communication Using IP Sockets
What tier should clustering



Web server
Application server
Database server

5. Load Balancing
 Which

Round-Robin DNS




kind of strategy
cheap, easy setup, and simplicity
no server affinity support
no support for high availability
Hardware




expensive, complex setup, and single point of failure
server affinity support
support for high availability
metrics

6. Load Balancing
 Factors



When server selected
How server selected (Policy)
Where is load balancing accomplished

7. Fail Over
 Solution


Request-level fail over
 when one server goes down, all subsequent
requests should be redirected to the remaining
servers in the cluster
Session-level fail over
 when one server goes down, another server
should be able to carry on with the sessions that
were being handled by the first server

8. Fail Over
 Factors



How are server failures detected
When is it right time to fail over and try another
server
What about system and application state at the
failed node

9. Session Persistence
 Solution



Memory-to-memory replication
File system session persistence
Database session persistence

10. Session Persistence
 Factors






How is state communicated
How often is it communicated
How is object state materialized
Is the state persistence mechanism efficient
Consistency of replicated state
Any network constraints in replicating the session
state

11. Proposed Cluster Setup I
 Highly
scalable
 Fault-tolerant
 Dynamically configurable
 Automatic cluster member discovery
 In-memory session state replication

12. Proposed Cluster Setup II
 Pluggable/configurable
load-balancing
policies
 Group membership notification
 No loss of message transmission
 Seamless from web application to server

13. Proposed Infrastructure

14. Realistic Context Deployment

15. System Architecture
Business Delegate Layer
Deployment Layer
Business Tier
Business Logic Layer
(Business Object)
Integration Tier
Data Access Object Layer
Architecture Component Layer
(Framework)
Domain Object Layer
(Domain Model / Entity)
Presentation Layer
(Servlet / JSP)
Presentation Tier

16. Testing Infrastructure

17. Testing Context Deployment

18. Value Object Layer
(Domain Object)
Presentation Layer
(Servlet / JSP)
Delegate Layer
(Service Locator)
Deployment Layer
(EJB / Web Services)
Business Logic Layer
(Business Object)
Data Access Object Layer
(DAO Object)
JUnit / TestNG Framework
Architecture Component Layer
(Framework)
Unit Test Architecture

19. Conclusion
 Next
Step?