Distributed Algorithms Simulator By Har-Tal Oded Supervised by Dr Shlomi Dolev Project’s goal: Designing and implementing a simulator for distributed algorithms, which will help to understand the behavior of distributed systems, and exploring the area of self-stabilizing distributed algorithms. B.Sc Final Project

Research

Development

Simulator’s Structure

Using The Simulator Running simulation Designing a distributed algorithm Allocating processors while dynamically loading their algorithms Implementing algorithm in Java,extending class processor and using processor API Defining system topology

Implementing a Distributed Algorithm

Processor inspector Communication Graph log Users menu Processor A Simulation View

Controlling a Simulation Enabling processor Watch value Watch name Processor ID Algorithm name Running processor a single step

Design Time Features Implementing algorithms in Java, using JDK. User can write any kind of desired algorithm. Extended yet flexible API provided. Easy methods were implemented for user convenience. Sending and receiving any kind of Java Objects by reference. User can design any kind of communication object. Self design of processor properties User can decide what properties to inspect, and how should they be inspected.

Run Time Features Loading Algorithms in run time. User can load any processor in system with any desired algorithm. Changing internal values of processors User can change any of the visible properties of each processor, during each stage of the running simulation. Changing distributed system topology User can add and remove processors, connect and disconnect them,and watch the consequences on the system. Defining simulation’s flow of control User can choose to run a single processor alone, disable some processors, run all processors one or many rounds. Viewing debugging information User can insert his code with debug messages and display them on simulator log window.

Example : Implementing Distributed BFS Sending and receiving data Performing algorithm Overriding method’s initialize and singleStep Extending Class Processor

Example : Running Distributed BFS Graph leader number in processor view = distance from leader Distance from leader