Denial-of-service (DoS) attacks are one of the major security challenges in the emerging cloud computing models. Currently, numerous types of DoS attacks are conducted against the various cloud services and resources, which target their availability, service level agreements, and performance. This paper presents an in-depth study of the various types of the DoS attacks proposed for the cloud computing environment and classifies them based on the cloud components or services, which they target. Besides, it provides a comprehensive analysis of the vulnerabilities utilized in these DoS attacks and investigates about the state-of-the-art solutions presented in the literature to prevent, detect, or deal with each kind of DoS attacks in the cloud. Finally, it presents open research issues.