Distributed architecture with JAVA RMI

Purpose !

When a task or a process is requiring too much ressources, it is sometimes convenient to split and share the work between peers for a better benefit of the distributed systems so saving time is ensured. Goal of this work is to show an example of an architecture that uses a "smart" Load Balancer giving jobs to different processing servers via Java RMI calls. Servers return a result to the LB that checks the result in a secure mode and doesn't if secure mode is deactivated.

Requirements

Java environnement set up on every station

Getting Started

• Begin by cloning/forking the repo.

Compilation

Simply execute the 'ant' command from root directory (Apache Ant is required on the system)

ant

!! This needs to be done on every server and LB you use for testing purpose !!

Load Balancer Conf File

The syntax of LB's configuration file must be like the following :

  name-server-1 @server1 @port-rmiregistry-server1
  name-server-2 @server2 @port-rmiregistry-server2
  ...

Parameters :

• name-server-X : Name of the server during the start up.

• @serverX : IP adress of the server.

• @port-rmiregistry-serverX : Port number used to join the RMI service.

If you have launched 3 different servers so your configuration file must look like the following :

  Example with default config.txt :

  toto 132.207.12.177 5023
  toto2 132.207.12.179 5023
  toto3 132.207.12.183 5023

Execution of processing servers

• Start the RMI registry with the rmiregistry command from the bin folder. Choose a port between 5000 5050 (5023 if a good default port value !). Don't forget to add an '&' to execute the rmiregistry outside of the current bash.

/opt/java/jdk8.x86_64/bin/rmiregistry 5023 & 

• Execute the following command :

chmod +x ./serveur

• Start the server with the following command

./serveur nameOfServer nbrOperationMax thresholdError registryAdress registryPort

Example :

./serveur foo 10 0 0 5023  

• Start as many server you like on separate station (preferably for accurate network delay accounting)

Execution of the Load Balancer

• Before starting the LB, make sure of having set configuration file. See Load Balancer configuration file section.

• Execute the following command :

chmod +x ./repartiteur ./repartiteurNonSecur

• Start the LB with the following command

./repartiteur {operations-file}.txt config.txt

Example :

./repartiteur donnees-4172.txt config.txt  

• Wait for the result to show up on the screen

Resources

This method has been implemented during Distributed Systems and Cloud Computing course (INF4410) within Ecole Polytechnique Montreal.