Cloud Security CCSP Book

Fault tolerance allows a system to continue functioning, even with degraded performance, if portions of it fail or degrade, without the entire system or service being taken down. It can detect problems within a service and invoke compensating systems or functions to keep functionality going. Although redundancy is similar to fault tolerance, it is more focused on having additional copies of systems available, either active or passive, that can take up services if one system goes down. Elasticity pertains to the ability of a system to resize to meet demands, but it is not focused on system failures. Automation, and its role in maintaining large systems with minimal intervention, is not directly related to fault tolerance.

With the entire software platform being controlled by the cloud provider, the standardization of configurations and versioning is done automatically for the cloud customer. This alleviates the customer's need to track upgrades and releases for its own systems and development; instead, the onus is on the cloud provider. Although licensing is the responsibility of the cloud customer within SaaS, it does not have an impact on compliance requirements. Within SaaS, development and maintenance of the system are solely the responsibility of the cloud provider.

The management plane will have broad administrative access to all host systems throughout an environment; as such, it represents the most pressing security concerns. A compromise of the management plane can directly lead to compromises of any other systems within the environment. Although hypervisors represent a significant security concern to an environment because their compromise would expose any virtual systems hosted within them, the management plane is a better choice in this case because it controls multiple hypervisors. Encryption and object storage both represent lower-level security concerns.

The management plane uses APIs to execute remote calls across the cloud environment to various management systems, especially hypervisors. This allows a centralized administrative interface, often a web portal, to orchestrate tasks throughout an enterprise. Scripts may be utilized to execute API calls, but they are not used directly to interact with systems. XML is used for data encoding and transmission, but not for executing remote calls. TLS is used to encrypt communications and may be used with API calls, but it is not the actual process for executing commands.