Cloud Computing Fundamentals
Domain scope
This HCIA-Cloud domain tests how well you can explain cloud characteristics, service and deployment models, and the Huawei Cloud resource hierarchy. Expect questions that ask you to classify a workload rather than recite definitions.
Core rules
- On-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service are the core cloud characteristics; Huawei Cloud delivers them through pay-per-use and yearly/monthly billing.
- IaaS gives VMs, block storage, and virtual networks; PaaS gives managed runtimes, databases, and middleware; SaaS gives a finished application.
- A region is a geographic location; an AZ is an isolated data center with independent power and network inside a region. Deploying across AZs improves availability, not latency between far regions.
- Elasticity matches resources to demand automatically; scalability is the capacity to grow. They are related but not synonyms.
- A project groups resources for isolation and billing; IAM controls identities and permissions.
Worked example
A team runs its own patched Linux VMs, connects them to a Huawei Cloud managed MySQL instance, and uses a third-party webmail service. Classify each layer. The VMs are IaaS because the team controls the OS and runtime. Managed MySQL is PaaS because Huawei Cloud operates the database engine, backups, and HA. Webmail is SaaS because the team only consumes the application. The reasoning is control: the more of the stack the provider operates, the higher the model.
Traps
Do not call a managed database IaaS just because it runs on a VM you cannot see. Do not say an AZ is a region. Do not treat multi-AZ as disaster recovery for a region-wide failure; it is high availability inside one region. Do not assume public cloud removes all customer security duties.