Alibaba Cloud Updated CAP-C01 Exam Questions and Answers by saint

CDN should form the content-delivery layer for cacheable video assets. Alibaba Cloud CDN distributes content to geographically dispersed edge nodes so viewers retrieve cached objects from nearby POPs rather than repeatedly connecting to a distant origin. Alibaba Cloud explicitly supports video-oriented CDN acceleration and edge delivery, reducing both end-user latency and origin bandwidth demand.

Auto Scaling addresses peak-time compute demand. It monitors workload conditions and automatically increases ECS capacity during traffic spikes, then scales resources back when traffic decreases. Alibaba Cloud specifically identifies streaming platforms with unpredictable demand as a typical Auto Scaling scenario.

Global Accelerator complements CDN and Auto Scaling where viewers or application endpoints are separated by long-distance or cross-border networks. GA routes traffic through Alibaba Cloud ' s optimized global BGP network, reducing latency, jitter, and packet loss. Alibaba documentation explicitly identifies video streaming as a latency-sensitive scenario that benefits from this architecture.

Tair can improve authentication or session performance, but it does not directly address video delivery quality or regional network performance. Therefore, CDN + Auto Scaling + Global Accelerator most directly satisfies the streaming requirement.

Study Guide reference: Delivering Services and Content on Alibaba Cloud — CDN, Global Accelerator, Auto Scaling, video delivery, and global traffic optimization.

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Option C provides the lowest-change migration path for the application tier. Rehosting the existing Windows workload on Windows Server ECS instances preserves its operating-system environment while distributing instances across availability zones improves resilience against zone-level infrastructure failures.

For the database tier, Option A provides the stronger managed architecture. Alibaba Cloud explicitly supports using DTS to migrate self-managed Oracle databases to PolarDB for PostgreSQL (Compatible with Oracle), including schema, full-data, and incremental-data migration for minimal migration downtime.

PolarDB ' s Oracle-compatible edition is specifically engineered to run Oracle workloads with minimal application modification. It supports Oracle-compatible data types, SQL constructs, PL/SQL features, OCI connectivity, packages, sequences, synonyms, and related functionality.

It also provides built-in high availability: failures are detected automatically and workloads can fail over to healthy nodes. This provides a more complete managed availability architecture than simply deploying independent self-managed Oracle servers across zones, which would additionally require Oracle-level replication/failover configuration.

Options B and D require substantial application refactoring and therefore conflict with the explicit requirement to minimize development changes.

Study Guide reference: Building Highly Available, Performant Cloud Architecture — workload migration, ECS multi-zone design, DTS, and PolarDB Oracle compatibility.

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OSS provides region-specific internal endpoints specifically for private access from Alibaba Cloud compute resources. When an ECS instance and an OSS bucket reside in the same region, the ECS instance can access the bucket using an internal OSS domain such as an oss- < region > -internal.aliyuncs.com endpoint. Traffic remains on Alibaba Cloud ' s internal network instead of traversing the public Internet.

This directly satisfies the security requirement without adding unnecessary networking components. The ECS instance does not require an EIP, NAT Gateway, or Internet connectivity for the OSS data path.

VPN Gateway is intended primarily for connecting VPCs to on-premises networks or other private networks; it is unnecessary for same-region OSS access. PrivateLink has legitimate private-service connectivity use cases, but the presence of a native OSS internal endpoint makes it unnecessary here. A VPC gateway endpoint may be relevant to certain Alibaba Cloud service integrations, but it is not required for this straightforward same-region ECS-to-OSS architecture.

The important exam design principle is to prefer a service ' s native private endpoint when one exists and the workload is already located inside the corresponding Alibaba Cloud region.

Study Guide reference: Building Enterprise-grade Networks on Alibaba Cloud — VPC private connectivity and OSS internal endpoints.

Tair (Redis OSS-Compatible) is the appropriate centralized session-state layer for an elastic, distributed application. When ECS instances frequently scale in and out, application sessions must not depend on the lifecycle of any individual compute node. By storing session tokens and session state in Tair, every ECS instance can retrieve the same session information, making the web/application tier effectively stateless and compatible with Auto Scaling.

Alibaba Cloud Tair is a fully managed Redis-compatible database designed for high throughput, low latency, elastic scalability, and high availability. Alibaba Cloud also documents session-oriented Tair use cases in which session tokens are stored as Redis/Tair data structures with TTL values, demonstrating precisely why the service fits distributed session management.

Session stickiness is weaker because it attempts to keep a user on a specific backend and therefore creates affinity to an instance that might be removed during scaling or failover. CloudMonitor is an observability service, not a session store. STS issues temporary Alibaba Cloud credentials and does not maintain application user sessions.

Consequently, separating session state from ECS compute by storing it in Tair gives the architecture the elasticity and fault tolerance required.

Study Guide reference: Distributed Architecture on Alibaba Cloud; Performant Architecture; Core Infrastructure Deep Dive.

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