CAP-C01 Exam Dumps - Alibaba Cloud Computing Questions and Answers

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 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.

Server Load Balancer SSL termination and Certificate Management Service provide the most direct combination for centralized TLS protection and certificate lifecycle management.

With SSL/TLS termination on the load-balancing layer, clients establish encrypted HTTPS or SSL connections to the SLB service. Encryption processing is performed centrally rather than requiring every backend instance to independently process incoming TLS handshakes. This simplifies the backend architecture and centralizes certificate configuration.

Certificate Management Service is specifically designed for issuing, importing, storing, monitoring, deploying, and renewing SSL certificates. Alibaba Cloud currently supports centralized certificate deployment to services including SLB, CDN, WAF, ECS, and other supported resources.

The integration is particularly strong because Alibaba Cloud ' s load-balancing services use certificates managed through Certificate Management Service. For example, SSL listeners require appropriate server certificates for encrypted client connections.

WAF adds web-application threat protection but is not primarily a certificate lifecycle automation solution. CDN with HTTPS is valuable for accelerated content delivery but is not required simply to centralize TLS termination. KMS protects cryptographic keys and secrets but does not replace SSL certificate deployment and lifecycle management.

Therefore, SLB plus Certificate Management Service provides encrypted access and centralized certificate administration with the lowest operational burden.

Study Guide reference: Securing Workloads on Alibaba Cloud — TLS, certificate lifecycle management, SSL termination, and secure load balancing.

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Global Accelerator is designed for precisely this class of global interactive application. Clients connect through Alibaba Cloud ' s nearby acceleration access points, after which traffic traverses Alibaba Cloud ' s optimized global network toward the most appropriate backend region. This reduces Internet routing variability and improves end-to-end latency for latency-sensitive workloads such as gaming.

GA listeners define the application protocol and ports, while endpoint groups represent backend deployments in different regions. With intelligent routing, GA can select a nearby healthy endpoint group and forward requests accordingly. Alibaba Cloud also provides endpoint health checks; when an endpoint becomes unhealthy, new requests can automatically be directed to healthy endpoints.

CDN is highly effective for static cacheable content but is not the correct primary mechanism for arbitrary real-time game traffic and regional backend health-based routing. RDS and Tair improve application data performance but do not solve global network acceleration.

Therefore, GA in front of regional ALBs provides the correct architecture: nearest-entry acceleration, Alibaba Cloud backbone transport, regional endpoint groups, health monitoring, and failover.

Study Guide reference: Delivering Services and Content on Alibaba Cloud — Global Accelerator, ALB, multi-region traffic management, and high availability.

Alibaba Cloud Cloud Firewall is the purpose-built managed network-security service for centralized traffic inspection, filtering, access control, and threat prevention. It protects multiple network boundaries, including traffic between cloud workloads and the Internet as well as east-west traffic involving VPC environments.

For Internet-facing assets, Cloud Firewall can inspect inbound and outbound traffic and apply access-control policies, DPI-based analysis, intrusion-prevention rules, and threat intelligence without requiring an organization to deploy and maintain a self-managed firewall appliance.

For private architectures, a VPC Firewall can inspect and control traffic traversing VPC boundaries through CEN or Express Connect. Access-control policies determine which traffic is permitted or blocked.

Simple Log Service can analyze network logs but does not itself enforce inline traffic filtering. Traffic Mirroring copies traffic to another inspection system and therefore requires additional tooling. Security Center focuses primarily on workload security posture, vulnerability management, malware protection, and host security rather than functioning as the VPC ' s inline network firewall.

Cloud Firewall therefore most closely reproduces the company ' s former inspection-and-filtering architecture as a fully managed cloud-native service.

Study Guide reference: Securing Workloads on Alibaba Cloud — Cloud Firewall, network inspection, access control, IPS, and VPC security.

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Option A offers the strongest combination of resilience, predictable baseline capacity, flexibility, and reduced cost. Nine standard pay-as-you-go ECS instances are spread evenly across three zones and can support the scheduled workloads that have strict SLA requirements. The remaining three instances use lower-cost preemptible/spot capacity for user jobs that can tolerate interruption or delay.

Alibaba Cloud describes spot instances as offering the same compute performance as ordinary pay-as-you-go ECS but at substantially lower prices, with the trade-off that capacity can be reclaimed. This makes spot capacity appropriate for interruption-tolerant workloads but inappropriate as the sole capacity supporting strict SLAs.

A Savings Plan discounts eligible pay-as-you-go ECS usage while preserving significantly greater flexibility than traditional reserved-instance matching. Current Alibaba Cloud documentation states that Savings Plans apply discounts to pay-as-you-go usage and can offer flexibility across instance configurations; they do involve a one- or three-year hourly spend commitment, but they do not provision or reserve fixed ECS capacity.

Options C and D concentrate too much reliable capacity into fewer zones or place excessive workload on interruptible capacity. Option A therefore provides the best workload-tiering and multi-zone design among the available choices.

Study Guide reference: Building Highly Available, Performant Cloud Architecture — multi-zone ECS, workload resilience, Savings Plans, and spot instances.

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Express Connect and CEN Transit Router provide the enterprise networking foundation required for a multinational hybrid environment. Express Connect gives the company ' s on-premises infrastructure dedicated private connectivity to Alibaba Cloud. A Virtual Border Router can then attach to a CEN Transit Router, allowing the data center to communicate privately with VPCs in the same region and across other regions.

CEN provides centralized routing for VPCs, VBRs, inter-region connections, and other network attachments. This avoids the operational complexity and poor scalability of maintaining large meshes of VPC peering links or independent VPN connections.

For network visibility, CEN Transit Router flow logs integrate directly with Simple Log Service. These flow logs capture five-tuple traffic information, bytes, packets, and connection details and deliver the records to SLS for monitoring, troubleshooting, compliance analysis, and long-term querying.

Security Center supplements this design by providing centralized security posture and workload-security management. In a comprehensive enterprise implementation, network access controls and security policies are applied alongside this centralized connectivity architecture.

VPC peering becomes difficult to administer at multinational scale, individual VPN gateways add operational complexity, and Global Accelerator is designed primarily to accelerate application access rather than replace an enterprise hybrid WAN.

Study Guide reference: Building Enterprise-grade Networks on Alibaba Cloud — Express Connect, CEN, Transit Router, SLS, and centralized hybrid networking.

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The public web tier needs an inbound security-group rule permitting TCP 443 from Internet clients. Therefore, Option E is required. Security groups act as virtual firewalls and should expose only application ports required by the workload. Alibaba Cloud recommends allowing public access only to necessary web-service ports such as HTTPS 443 while keeping internal services inaccessible from the Internet.

For the database tier, access should be limited to ECS instances belonging to the web-server security group. Alibaba Cloud RDS for MySQL supports associating an ECS security group with an RDS instance, allowing ECS instances in that group to connect without adding every server address individually to an IP whitelist. This is particularly useful when application-server membership changes dynamically.

Option B is overly broad because every resource within the public vSwitch ' s CIDR could potentially be authorized rather than only the approved web tier. Option C would prevent legitimate database traffic. Option D is unnecessary because RDS access behaves as an allow-list model: only explicitly authorized addresses or associated security-group members should be granted database access.

Thus, Internet clients reach the web tier only over HTTPS, while MySQL accepts access only from the authorized application servers.

Study Guide reference: Securing Workloads on Alibaba Cloud — Security Groups, RDS access control, least privilege, and tiered network segmentation.

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VPC peering provides direct private communication between two VPCs without exposing either application or database traffic to the public Internet. Alibaba Cloud VPCs are isolated by default. After creating a peering connection and configuring the required bidirectional routes, resources in VPC A and VPC B can communicate using private IP addresses. VPC peering supports same-account and cross-account connections as well as same-region and cross-region configurations.

This is materially more secure than exposing the database publicly. The application ' s existing EIP does not need to participate in database connectivity; the application can use its ECS private address when communicating across the peering link. Security-group and database whitelist rules should then restrict access to only the required source CIDRs and ports.

Option A intentionally routes database access through public addressing. Option B introduces an unnecessary proxy server, additional management overhead, and another failure point. Option D creates the largest attack surface by making the database Internet-accessible.

The design principle is straightforward: when workloads in two Alibaba Cloud VPCs require direct communication, establish private network connectivity and keep sensitive database traffic off the Internet.

Study Guide reference: Building Enterprise-grade Networks on Alibaba Cloud — VPC isolation, VPC peering, routing, and private database access.

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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