Distributed Systems Project 2015-2016

Group 64 - Campus Alameda

André Águas - 78854 - andre.aguas@ist.utl.pt

João Neto - 78745 - joao.b.neto@ist.utl.pt

Description

Development of a sistemy based in SOAP Web Services, implemented in the J2EE plarform, to aggregate services of good transporters, similar to Uber's service with passengers.

Architecture

The main components of the system are clients, a broker, transporters and a name server (UDDI). The transporters publish themselves in the name server, which is used by the broker to find them and negotiate the services requested by the clients. Here is a simple figure of the system's architecture:

The broker is the most complex component. It is divided in 4 modules:

broker-ws that communicates with the client
transporter-ws-cli that communicates with the transporters
ca-ws-cli that communicates with the CA
broker-ws-cli that communicates with the backup broker

The client is just a broker-ws-cli module and the transporter a transporter-ws.

In addition, the system is composed by other components that guarantee reliability and security:

A backup broker to provide primary
A CA to generate public key certificates used in digital signatures. These signatures guarantee the authenticity, fresheness and integrity of the communication between the broker and the transporters.

Operation

All the operations performed by the 3 parties are described in a WSDL contract.

The basic rules of the protocol are the following:

The client requests a transport from an origin to a destination for a maximum price
The broker asks a budget to all the transporters
The broker assigns the task to the transporter which offered the lowest value

All the states of a service are described bellow:

There are some rules concerning max and min price as well as areas of operation of transporters according to odd or even id (for further details refer to enunciado (portuguese only))

Dependencies

Refer to INSTALL.md

Installation instructions

Environment

[0] Boot the OS

Linux or Mac OS X

[1] Initiate the support servers

JUDDI:

./juddi-3.3.2_tomcat-7.0.64_9090/bin/startup.sh

[2] Create temporary folder

mkdir temp
cd temp/

[3] Obtain source code of the project

git clone https://github.com/abaguas/UpaTransporter.git (via https) 
git clone git@github.com:abaguas/UpaTransporter.git (via ssh)

[4] Install auxiliary libraries and modules

cd uddi-naming
mvn clean install

Certificate Authority

[1] Build and execute the server

cd ca-ws
mvn clean install
mvn exec:java

[2] Build the client

cd ca-ws-cli
mvn clean install

Transporter

[1] Build and execute the server

cd transporter-ws
mvn clean install
mvn exec:java

and in other tab (the tests that will be run on the broker client require 2 transporters executing)

cd transporter-ws
mvn exec:java -Dws.i=2

[2] Build the client

cd transporter-ws-cli
mvn clean install

Broker

[1] Build and execute the server

cd broker-ws
mvn clean install
mvn exec:java

[2] Build the client client

cd broker-ws-cli
mvn clean install

Running instructions

You can keep the 2 Transporters and the CA running. Then launch the Broker:

cd broker-ws
mvn exec:java

And launch the backup Broker:

cd broker-ws
mvn exec:java -Dws.br=2

Follow the instructions on both terminals (i.e. on the primal Broker press "enter" and, after, on the backup Broker press "enter")

Now launch the Client:

cd broker-ws-cli
mvn exec:java

You can (and should) kill the Broker's process to verify that the primary Backup is working correctly.

Disclaimer: It was not the aim of this project to provide a interface to the client, it only runs a small demonstration. The tests verify the correctness of all the operation implemented in the system.

PS: The prints are meant to better understand the operations that the system is performing.

END