Cloud Application Characteristics

Because cloud computing is related to a number of other technologies, it is best defined by the presence of a number of characteristics. These represent ideals that people want for the applications that run on the cloud:

• Incremental Scalability. Cloud environments allow users to access additional compute resources on-demand in response to increased application loads.
• Agility. As a shared resource, the cloud provides flexible, automated management to distribute the computing resources among the cloud's users.
• Reliability and Fault-Tolerance. Cloud environments take advantage of the built-in redundancy of the large numbers of servers that make them up by enabling high levels of availability and reliability for applications that can take advantage of this.
• Service-oriented. The cloud is a natural home for service-oriented applications, which need a way to easily scale as services get incorporated into other applications.
• Utility-based. Users only pay for the services they use, either by subscription or transaction-based models.
• Shared. By enabling IT resources to be consolidated, multiple users share a common infrastructure, allowing costs to be more effectively managed without sacrificing the security of each user's data.
• SLA-driven. Clouds are managed dynamically based on service-level agreements that define policies like delivery parameters, costs, and other factors.
• APIs. Because clouds virtualize resources as a service they must have an application programming interface (API).