ThorFI: A Novel Approach for Network Fault Injection as a Service

TL;DR

ThorFI is an innovative fault injection tool for virtual cloud networks that enables non-intrusive testing and isolation, demonstrated through case studies in NFV and high-availability cloud applications.

Contribution

This paper introduces ThorFI, a new fault injection approach for cloud virtual networks that ensures non-intrusiveness and tenant isolation, with open-source implementation and practical case studies.

Findings

Fault injection revealed 4%-34% of IMS test cases fail under faults.

Faults can propagate across virtual network segments, impacting throughput and response time.

ThorFI enhances functional testing by systematically injecting faults in cloud environments.

Abstract

In this work, we present a novel fault injection solution (ThorFI) for virtual networks in cloud computing infrastructures. ThorFI is designed to provide non-intrusive fault injection capabilities for a cloud tenant, and to isolate injections from interfering with other tenants on the infrastructure. We present the solution in the context of the OpenStack cloud management platform, and release this implementation as open-source software. Finally, we present two relevant case studies of ThorFI, respectively in an NFV IMS and of a high-availability cloud application. The case studies show that ThorFI can enhance functional tests with fault injection, as in 4%-34% of the test cases the IMS is unable to handle faults; and that despite redundancy in virtual networks, faults in one virtual network segment can propagate to other segments, and can affect the throughput and response time of the cloud application as a whole, by about 3 times in the worst case.