Abstract
Various information systems are widely used in the information society era, and the demand for highly dependable system is increasing year after year. However, software testing for such a system becomes more difficult due to the enlargement and the complexity of the system. In particular, it is often difficult to test parallel and distributed systems in the real world after deployment, although reliable systems, such as high-availability servers, are parallel and distributed systems. To solve these problems, the authors propose a software testing environment for dependable parallel and distributed system using the cloud computing technology, named D-Cloud. D-Cloud consists of the cloud management software as the role of the resource management, and a lot of virtual machine monitors with fault injection facility in order to simulate hardware faults. In addition, D-Cloud introduces the scenario manager, and it makes a number of different tests perform automatically. Currently, D-Cloud is realized by the use of Eucalyptus as the cloud management software. Furthermore, the authors introduce FaultVM based on QEMU as the virtualization software, and D-Cloud frontend that interprets test scenario, constructs test environment, and dispatches commands. D-Cloud enables automating the system configuration and the test procedure as well as performing a number of test cases simultaneously and emulating hardware faults flexibly. This chapter presents the concept and design of D-Cloud, and describes how to specify the system configuration and the test scenario. Furthermore, the preliminary test example as the software testing using D-Cloud is presented. As the result, the authors show that D-Cloud allows easy setup of the environment, and to test the software testing for the distributed system.
TopA number of fault injection techniques in program tests have been proposed. DOCTOR (Han, 1995) is a software fault injector, which supports memory faults, CPU faults, and communication faults. However, software fault injection in the DOCTOR requires modification of the source codes to be tested. Xception (Carreira, 1998) uses the kernel module to inject the fault, and the tester sets the hardware breakpoint to the specified address. When the process reaches the breakpoint, the fault is injected into the register or memory as an incorrect value.
On the other hand, BOND (Baldini, 2000) uses a special agent to intercept the system call of Windows NT 4.0 OS. The agent hooks the system call from the target application and returns an incorrect value to the application. Although this scheme does not require any modification of either the OS or the target application, the fault can only be injected to a location that can be accessed through the software, such as the register and memory. Moreover, this scheme cannot be applied to test the OS.
FAUmachine (Potyra, 2007) performs a software test using virtual machines for the fault injection mechanism. However, since FAUmachine does not provide an automated test environment, the tester must configure the test environment manually.