A Study of Sun Microsystem

1
A Study of Sun Microsystems Jini Architecture

• Casey Detorie
• CS522
• 11 December 2002

2
Purpose of Study

• Develop solid understanding of Jini
• Characterize the responsiveness of the Jini
  lookup service
• Characterize the robustness of a simple Jini
  network

3
What is Jini?

• Suns Java-based network architecture
• Implements Suns paradigm of The Network
  is the Computer

Work Req
Result

• Complementsnot a substitute for--CORBA

4
Jini Features

• Extreme flexibility
• Clients and services are decoupled
• Jini lookup service
• Robustness of network
• Jini services are leased in lookup service
• Ease of network growth
• Discover and join protocols enable new services
  to join
• Handles client-server synchronization issues
• Clients register with lookup service for event
  notices

5
Basic Jini Procedure
Jini lookup service
2
1
3
Client
Service A
4
6
Key Roles of Lookup Service

• Discovery for clients and services
• Provide lookup support for clients
• Return service proxy to client
• Event solicitations/notifications with clients
• Register/store service proxies
• Assign unique IDs to services
• Maintain leases for registrations and
  notifications

7
Lookup Service Responsiveness

• How responsive is the lookup service in terms of
  the time it takes to return a proxy to the
  client?
• Ran two versions of client
• Smart client Knew IP of service
• Dumb client Had to use lookup service
• Compared times needed to complete server
  computation and get result back

8
Lookup Service Responsiveness

• Is response time affected by number of services
  registered in lookup service?
• Repeated above experiment using 1, 2, and 3
  services registered

9
Jini Network Robustness

• How quickly can a simple Jini network recover
  from a network outage while in mid-service to a
  client?
• Set up two simple services and one client
• Kill one server while it was servicing client
• Determine time needed for backup service to
  recover

10
Jini Conclusions

• Intuitive solution to complex networking problems
• Provides for adaptable, flexible, robust networks
• Major limitation requires use of Java JVM in
  most of network
• What to do with mixed platform/OS/hardware
  networks?

11
Results

• Mixed and inconsistent
• Heavily dependent on network traffic volume
• Standard deviation seemed high
• Further experimenting needed
• Lookup Service Responsiveness
• Smart vs. Dumb client lookup service added
  3-8 additional time
• Multiple services on lookup service no
  significant penalty (simple array as registry
  data structure?)

12
Results

• Network Robustness
• Recover relatively quick 250-500?s
• Possibly more complicated with more complex
  services

13
Resources

• Li, Sing. Professional Jini. Wrox Press Ltd.
  2000.
• www.jini.org
• Sun Microsystems, Inc. The Jini Specification
  v1.2.
• Edwards, Keith W. Core Jini. Pearson Education.
  2000.