Option B provides the simplest consolidated content-delivery architecture. Alibaba Cloud CDN can use multiple origins, and current CDN functionality supports origin-selection rules based on parameters such as request path, headers, query strings, and cookies. This allows static requests to be associated with an OSS origin while application requests are forwarded toward the ALB-backed application tier.

Static objects stored in OSS benefit directly from CDN edge caching. Requests are routed to nearby CDN points of presence, and cached resources can be returned without repeatedly accessing the OSS origin, reducing both latency and origin load.

Dynamic responses are generally not cached because they are generated uniquely for requests. They can still be routed to the application origin according to the configured origin rules.

The Global Accelerator alternatives create an unnecessarily fragmented architecture and attempt to use separate acceleration paths where one CDN-facing domain and origin-routing configuration can satisfy the question with fewer components. They also introduce additional DNS and acceleration configuration.

Therefore, a single CDN delivery layer with OSS and ALB-backed origins, combined with Alibaba Cloud DNS directing the application domain to CDN, produces the lowest configuration overhead.

Study Guide reference: Delivering Services and Content on Alibaba Cloud — CDN, OSS acceleration, ALB origins, and intelligent content delivery.

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The architectural defect is that application state is stored independently on local block storage attached to each ECS instance. ALB can route successive requests to either backend, so each server exposes only the files stored on its own EBS disk. The correct solution is therefore to separate persistent shared data from individual compute instances.

Alibaba Cloud File Storage NAS provides shared file storage that can be mounted concurrently by multiple ECS instances. A single NAS file system becomes the authoritative repository for uploaded documents, so regardless of which ECS instance receives a request, both instances access the same underlying dataset. Alibaba Cloud explicitly supports mounting NAS on multiple ECS instances for shared access.

Periodic EBS synchronization is operationally fragile and introduces consistency windows. ALB session persistence would merely hide the architectural problem and would fail when an ECS instance becomes unavailable or is replaced. Sending every request to both servers would also complicate application logic and still leave divergent storage.

Moving the data to NAS converts the application tier into a horizontally scalable compute layer while maintaining one consistent shared filesystem.

Study Guide reference: Core Infrastructure Deep Dive — ECS storage patterns, File Storage NAS, shared storage, and stateless application architecture.

The three explicit requirements are centralized key management, encryption in transit, and encryption at rest.

KMS satisfies centralized cryptographic-key management. It provides secure key creation, storage, lifecycle management, access control, and integration with Alibaba Cloud services such as databases and storage. Customer-managed software or hardware-protected keys can also be used where stricter compliance controls are required.

Certificate Management Service provides SSL/TLS certificates that establish encrypted HTTPS/TLS communication and verify server identity. TLS prevents sensitive transaction information from being transmitted as readable plaintext across network connections.

Transparent Data Encryption protects database data at rest. Alibaba Cloud RDS documentation identifies TDE as an encryption layer protecting database data files and backups without requiring applications to perform the underlying encryption themselves. RDS also separately supports SSL for database connection encryption.

Security Groups are an important network-access control, but the question requires exactly three controls specifically addressing encryption and centralized key management. Redis session management is unrelated.

The resulting security architecture therefore uses KMS for keys, TLS certificates for data in transit, and RDS TDE for persistent data at rest.

Study Guide reference: Securing Workloads on Alibaba Cloud — KMS, TLS/SSL, RDS encryption, TDE, and cryptographic key governance.

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This is fundamentally a lift-and-shift filesystem workload. The applications already depend on standard operating-system file interfaces, and the requirement explicitly states that application code should not be changed. ECS therefore preserves the existing Linux and Windows execution environments, while File Storage NAS supplies managed shared filesystem semantics.

Alibaba Cloud NAS supports NFS and SMB protocols and is designed specifically for workloads migrating from traditional file servers. Alibaba documentation describes NAS as appropriate for lift-and-shift applications because existing applications can continue using standard filesystem calls, path structures, and file-locking behavior without rewriting file I/O logic.

For cross-operating-system sharing, Alibaba Cloud recommends SMB when Linux and Windows clients must access the same filesystem, and Linux ECS can mount SMB when cross-platform data sharing is required.

OSS would change the storage interface from filesystem semantics to object APIs, normally requiring application changes. Message Queue changes the application ' s data exchange architecture. ACK introduces unnecessary containerization complexity.

Therefore, Linux ECS + Windows ECS + managed NAS most closely preserves the existing application model while eliminating the operational problems associated with manually synchronized on-premises file systems.

Study Guide reference: Core Infrastructure Deep Dive — ECS migration, File Storage NAS, NFS/SMB, and lift-and-shift architecture.

The core problem is durability during transient processing or network failures. A topic provides publish/subscribe notification delivery, but placing an SMQ queue behind the topic creates a persistent buffer between the notification producer and the Function Compute consumer. Alibaba Cloud supports subscribing a queue to an SMQ topic so that every message published to the topic is copied into the queue and retained for consumption.

Function Compute should then process records from the queue. Queue semantics provide the required failure recovery: after a consumer receives a message, it becomes temporarily invisible. The consumer deletes the message only after successful processing. If processing fails—for example because of a temporary connectivity problem—the message is not deleted and becomes visible again after the visibility timeout, allowing another processing attempt.

Function Compute also supports SMQ queue triggers with configurable retries, fault-tolerance behavior, and dead-letter handling, which can further strengthen this architecture.

Increasing memory does not fix network reliability, and multi-region deployment alone does not guarantee message persistence. A durable queue therefore prevents transient failures from silently losing ingestion work.

Study Guide reference: Core Infrastructure Deep Dive — Simple Message Queue, Function Compute, durable asynchronous processing, retries, and decoupled event-driven architecture.

The application needs asynchronous decoupling between high-volume ingestion and database writes. Simple Message Queue provides exactly this load-leveling pattern. The first Function Compute function can acknowledge incoming requests quickly and place each item into SMQ. A second function consumes the queued messages and writes them to RDS at a rate the database can sustain.

SMQ is a distributed managed messaging service specifically designed to decouple producers and consumers. Alibaba Cloud identifies traffic-spike buffering, asynchronous processing, and independent component scaling as core SMQ use cases. Queue messages are delivered at least once during their validity period, significantly improving durability compared with directly coupling every incoming API request to a database write.

Function Compute also integrates directly with SMQ queues and topics as event sources, reducing custom integration and infrastructure management.

Kafka could also provide durable asynchronous messaging, but it is a more elaborate streaming platform than necessary for this workload and therefore carries additional configuration complexity. Moving to ECS reintroduces server administration, while replacing RDS does not solve the ingestion decoupling problem.

Study Guide reference: Core Infrastructure Deep Dive — Function Compute, messaging architectures, asynchronous processing, and scalable application integration.

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Option A refers to PolarDB Global Database Network (GDN), Alibaba Cloud ' s architecture for connecting PolarDB clusters across regions. A GDN contains a primary cluster and secondary regional clusters. Data changes are continuously replicated, local reads can be served by regional clusters, and write operations are routed to the primary cluster. Maintaining a single authoritative write path is particularly important for reservation transactions where concurrent booking operations must be controlled consistently.

Option C provides resilient application capacity by deploying ECS application servers in multiple regions and using ALB within each regional deployment to distribute requests among healthy instances. In a complete production implementation, a global routing mechanism such as DNS traffic management or Global Accelerator would normally direct users between those regional application stacks.

Function Compute is suitable for payment-gateway integrations because payment callbacks and API interactions are event-driven or request-driven workloads. Function Compute can be exposed securely through API Gateway, which provides routing, authentication, traffic control, and API management without persistent integration servers.

OSS versioning is useful for protecting stored objects but does not supply the transactional database, regional application availability, or payment-processing functionality required here.

Study Guide reference: Building Highly Available, Performant Cloud Architecture — multi-region PolarDB, GDN, regional application tiers, ALB, and serverless integration.

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Basic security groups support group-based authorization, allowing one security group ' s rules to reference another security group rather than requiring administrators to maintain long lists of individual IP addresses. Alibaba Cloud explicitly recommends source-security-group authorization for internal application communication because it is more manageable than maintaining individual private IP addresses or CIDR ranges.

This distinction is important because advanced security groups do not support another security group as an authorization object. Their primary benefit is higher private-IP capacity for very large deployments, not simplified service-to-service authorization.

For workloads residing in different VPCs, network connectivity must first exist through VPC Peering, Cloud Enterprise Network, PrivateLink, or another appropriate mechanism. Security groups do not themselves establish cross-VPC routes; they enforce authorization once the relevant network path exists.

Centralized logging provides visibility but does not simplify the actual authorization rules. Network ACLs operate at the vSwitch/subnet boundary and are less appropriate for application-tier identity based on security-group membership.

Thus, basic security groups with group-based authorization provide the intended simplified access-control model.

Study Guide reference: Securing Workloads on Alibaba Cloud — security groups, group-based authorization, least privilege, and VPC workload segmentation.

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The requirements explicitly identify two separate environments: a production ACK cluster using stable pay-as-you-go ECS capacity and a dedicated development cluster that is used only intermittently. Option D satisfies both requirements while preserving ACK-managed node-pool operations.

For the development cluster, preemptible instances—now generally described as spot instances in current Alibaba Cloud documentation—are appropriate because the workload is temporary, interruption-tolerant, and cost-sensitive. Alibaba Cloud states that spot capacity can reduce compute costs substantially compared with ordinary pay-as-you-go instances. ACK node pools can use spot instances and can automatically perform scaling and replacement operations.

The production cluster remains on pay-as-you-go nodes, avoiding the reclamation risk associated with spot capacity. A separate managed development cluster also preserves workload isolation.

Option A does not provide the required second development cluster and imposes subscription commitment. Option B requires Eric to maintain an external Auto Scaling and bootstrap mechanism, contradicting the desire for ACK to manage nodes. Option C again describes only one cluster and fails to retain the required production environment.

Study Guide reference: Core Infrastructure Deep Dive — ACK managed clusters, node pools, spot/preemptible ECS, and cloud cost optimization.

Data Management Service is specifically designed to centralize database administration, authorization, and governance. Its permission model provides fine-grained control over instances, databases, tables, columns, rows, and sensitive data. Administrators can control logon, query, export, and change privileges while maintaining centralized governance rather than manually coordinating several independent services.

DMS is also appropriate where the organization needs auditable database access. Alibaba Cloud explicitly describes DMS authorization scenarios that include controlling RDS access and auditing employee data access.

RAM controls permissions to Alibaba Cloud resources and APIs, but combining RAM with ActionTrail would require multiple mechanisms and would not provide DMS ' s database-object-level permission model. An RDS IP whitelist is useful as a network access restriction but cannot express granular user permissions or provide centralized database governance. WAF protects HTTP/HTTPS applications and is not the appropriate control plane for direct RDS database authorization.

DMS therefore provides the required access control and audit functionality with the lowest operational complexity by consolidating database security administration into a purpose-built managed service.

Study Guide reference: Securing Workloads on Alibaba Cloud — DMS access control, database governance, RDS security, and auditing.