Cloud Computing Fundamentals and Alibaba Cloud Overview
Core concepts
Alibaba Cloud's global infrastructure is organized as Regions (geographic areas) containing Zones (isolated datacenters with independent power and network). A region is selected for latency, data-residency, and service availability; zones are selected for high availability within a region. Understand the shared responsibility model: Alibaba Cloud secures the physical plant and hypervisor; you secure your guest OS, data, identities, and configurations.
Service families you must recognize by purpose, not memorization: ECS (compute), VPC/SLB/CDN (network), OSS/NAS/Disk (storage), ApsaraDB/RDS/PolarDB (databases), RAM (identity), CloudMonitor (observability), and ActionTrail (audit). Know the difference between IaaS (you manage OS and above) and PaaS/managed services (provider manages patching and scaling).
Traps in questions
- Region vs. zone confusion: cross-zone replication is common inside a region; cross-region replication must be explicitly configured and is often asynchronous.
- Service-purpose swaps: OSS is object storage (unstructured, HTTP API), NAS is shared file storage (NFS/SMB), and cloud disks are block storage attached to one ECS instance (with multi-attach exceptions).
- "Most cost-effective" vs. "most available": pay-as-you-go is flexible, subscription/reserved is cheaper for steady workloads; single-zone is cheaper but not HA.
- Data residency: regulated data may not leave a region; answer choices that move data across regions may be non-compliant.
Rule of thumb
Design for a region but deploy across at least two zones for production. If a question asks for the best availability posture with minimal operational burden, prefer a managed, multi-zone service over self-managed single-instance designs.
Worked example
A team needs low-latency access for users in Singapore and must keep data in-country. Choose the Singapore region, deploy across two zones, and keep replication inside that region. Reject cross-region replication options even if cheaper or more durable.