Team Members Lora zalmover Roni Brodsky Academic Advisor Professional Advisors Dr. Natalya Vanetik Prof. Shlomi Dolev Dr. Guy Tel-Zur

 Introduction  Solution  Motivation  System Requirements  System Architecture  User Interface

Cloud computing is where data, software and applications, or computer processing power are accessed from a cloud of online resources. Cloud computing today There are commercial tools that provide Cloud computing services, like EC2 of Amazons. Also existing an open-source tools like Eucalyptus which enables users run programs on their own resources and provides a detailed view of what would otherwise be the black box of cloud-computing services.

Motivation for cloud computing  enables individual users to access their data or applications from any device.  allows the organizations to reduce their capital costs by purchasing hardware and software as a utility service. Rather than purchasing servers, software, data center space or network equipment, clients instead buy those resources as a fully outsourced service. Fault tolerance Fault-tolerance is the property that enables a system (often computer-based) to continue operating properly in the event of the failure of (or one or more faults within) some of its components.

In our project we established a cluster of cloud computing. We used an open-source program for managing cloud computing called "Eucalyptus ". On top of the cloud we developed an algorithm for fault tolerance, which purpose is to identify errors during the execution of a program, and handle them with Fault-tolerance by replication. Replication means providing multiple identical instances of the same system or subsystem, directing tasks or requests to all of them in parallel, and choosing the correct result on the basis of a quorum. After identifying the failure our system tries to recover several times.

In order to demonstrate the motivation of our system, we will present an example. Suppose you have a statistical algorithm that determines whether a given number is prime. Since the result is statistical, there is some probability for getting wrong answer. Our system significantly increases the chances of getting the right answer. Several replicas will run the same algorithm simultaneously, and the answer will be determined by the majority.

Main functional requirements:  Running a program without support of fault tolerance on cloud computing cluster  Running a program with support of fault tolerance on cloud computing cluster (detection and recovery)  Statistical information

Server 1Server 2Server 3... Server i Cloud Client Server FTDR Application Client