Modern distributed applications are moving toward a microservice architecture, in which each service is developed and managed independently, and new features and updates are delivered continuously. A guiding principle of microservice architecture is that it must be built to anticipate and mitigate a variety of hardware and software failures. In order to test the fault handling capabilities of microservces, this paper presents IntelliFT, a feedback-based, automated failure testing technique for microservice based applications, which aims to expose the defects in the fault-handling logic quickly. The initial experimental result on a medium-size microservice benchmark system shows that the proposed approach is effective.