Performance Evaluation of Java RMI

A Distributed Object Architecture for Internet Based Applications

By Idowu Samuelsamido@student.ltu.se

Paper Information

Department of Computer and Information Sciences University of North Florida Jacksonville -Sanjay P. Ahuja & Renato Quintao

Publication Year: 2000

Reason for selection: I Simply got intrigued by the features of RMI We had a lecture on RMI

Introduction

In the Good Old Days...Distributed applications have been around for some time now and many tools and standards have been used in the past to develop these applications.

• Berkeley sockets (BSD Socket API)• Remote Procedure Call (RPC)• Distributed Computing Environment (DCE)

Problems with earlier standards

Use Low-level, data transmission APIs and protocols

sockets programming is tedious

Error prone for implementing complex protocolsAll use procedural paradigm which gets very complex when trying to develop distributed applications

Solution

DISTRIBUTED OBJECT SYSTEMS

Java RMI (Remote Method Invocation)

One of the major distributed object systems available today: Java RMI is a Java based approach

for distributing objects.

Why evaluate performance of RMI?

Since Java RMI is increasingly being used in Internet based applications

• Designers of distributed object systems need to be aware of the performance in terms of– response time– services provided– architectural characteristics of RMI

Our Focus?

– To Evaluate the performance of RMI empirically and compares its performance with the Java Sockets API

– Evaluates the benefits of RMI to distributed application developers

– Insight into the performance aspects and other tradeoffs involved when using the Java RMI distributed object architecture.

Why compare with Java Sockets API?

– Sockets have the least overhead as compared to other distributed technologies.

– Java based sockets are easy to use

Features of java RMI

– Remote object implementations.– Client interfaces, or stubs, to the remote object.– A remote object registry for finding objects on the

network.– A network protocol for communication between

remote objects and their client (JRMP, i.e. Java Remote Method Protocol).

– A facility for automatically creating (activating) remote objects on demand.

Basic RMI architecture

• The stub / skeleton layer: provides the interface that client and server application objects use to interact with each other.

• Remote reference layer: middleware between the stub/skeleton layer and the underlying transport protocol.

• The transport protocol layer: binary data protocol that sends remote object requests over the wire.

Basic RMI architecture (Contd)

Clie

ntS

erve

r

return parameters

method invocation on client

parameters

method invocation on server

RMI Client/Server model

Basic RMI architecture (Contd)

Client Server

Stubs Skeletons

Remote Reference

Remote Reference

Transport

Performance Evaluation

2 client-server application was developed using RMI and the Java Sockets API

Both apps were developed and executed on the same Sun workstations running Solaris

The LAN environment was a 100 Mbps Fast Ethernet.

Features of the Server/Client App

• multithreaded “database” server that access records

• The server performs read and update operations. (common in web-based applications)

• response time seen by the user is an important quality of service parameter.

• the response time was used as a basis for comparison of the two technologies

Read Operation Result

1 2 3 4 5 6 70

10

20

30

40

50

60

70

Read Operation

RMISocket

Tim

e (M

illis

econ

ds)

Number of Clients (threads)

Update Operation Result

1 2 3 4 5 6 70

20

40

60

80

100

120

140

Update Operation

RMISocket

Tim

e (M

illis

econ

ds)

Number of Clients (threads)

Result Discussion

• the Socket version of the application has better response times than the RMI version but not by a significant amount.

• But this is more than offset when we consider that – RMI offers the fastest development time since no low

level protocol design is required

Suggestion & Conclusion

RMI performance is not significantly slower than the Java Sockets version of the same client-server application.

RMI reduces development time significantlyRMI is easier to learnIntegrates into Java applications seamlessly

THANK YOU