The most likely cause of accessibility and performance issues during specific times is oversubscription. This happens when more users are trying to access the database than the hypervisors can handle, due to their resources being allocated to more virtual machines or processes than they can efficiently support.
Resource management concepts such as avoiding oversubscription are covered under the Management and Technical Operations domain of the CompTIA Cloud+ exam objectives.

Containers are the best compute resources to optimize cloud resources and lower the overhead caused by managing multiple operating systems. Containers encapsulate applications and their dependencies into a single executable package, running on a shared OS kernel, which reduces the need for separate operating systems for each application and simplifies resource management.
CompTIA Cloud+ materials discuss management and technical operations in cloud environments, including the use of containers to improve resource utilization and operational efficiency by minimizing the overhead associated with traditional VMs.

When migrating a highly available application normally hosted on a local VM cluster for usage with an external user population, the best migration type would be on-premises to cloud. This allows the application to leverage the cloud's scalability and reach, providing better access to the external users. References:
CompTIA Cloud+ Study Guide (Exam CV0-004) - Chapter on Cloud Migration

GraphQL is the best option for transferring data over the internet with programmatic access and querying capabilities. It is a query language for APIs and a runtime for executing those queries with existing data, providing a more efficient, powerful, and flexible alternative to the REST API.
Data transfer and querying methods are part of the technical knowledge associated with cloud computing, as included in CompTIA Cloud+.

Developers use code versioning to keep track of changes made during software development projects. It is a system that records changes to a file or set of files over time so that specific versions can be recalled later.
References: CompTIA Cloud+ Study Guide (Exam CV0-004) - Chapter on Software Development in Cloud Environments