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Alibaba CSA-C01 study materials
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Alibaba CSA-C01 practice questions

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Question 1Cloud Computing Fundamentals and Alibaba Cloud Overview

Which cloud service model delivers a complete application to end users over the internet while the provider manages servers, runtime, and application code?

  1. Platform as a Service (PaaS)
  2. Software as a Service (SaaS) Correct answer.
  3. Function as a Service (FaaS)
  4. Infrastructure as a Service (IaaS)

Explanation

In SaaS the provider operates the entire stack including the application, and the customer only consumes it, typically through a browser. PaaS and IaaS leave increasing portions of the stack under customer control. FaaS is a compute execution model rather than a full application delivery model.

Question 2Cloud Computing Fundamentals and Alibaba Cloud Overview

A team wants to run containerized workloads without provisioning or managing any servers. Which Alibaba Cloud service is designed for this requirement?

  1. Elastic Container Instance (ECI) Correct answer.
  2. Object Storage Service (OSS)
  3. Server Load Balancer (SLB)
  4. Elastic Compute Service (ECS)

Explanation

ECI is a serverless container service: users submit container specifications and the platform provisions the underlying compute automatically. ECS requires managing virtual machines, SLB distributes traffic, and OSS stores objects.

Question 3Cloud Computing Fundamentals and Alibaba Cloud Overview

Which statement best describes the shared responsibility model in cloud computing?

  1. The provider is responsible for every layer of security including customer data
  2. Security duties are divided between provider and customer depending on the service model Correct answer.
  3. The customer is responsible for physical data center security
  4. Responsibility shifts entirely to the customer once data is encrypted

Explanation

Under the shared responsibility model the provider secures the physical infrastructure and managed layers, while the customer secures what they control, such as identities, configurations, and data. The exact split varies by service model. Neither party is ever responsible for everything.

Question 4Cloud Computing Fundamentals and Alibaba Cloud Overview

Which characteristic of cloud computing lets a system automatically add capacity during a traffic spike and remove it afterward?

  1. Measured service
  2. Broad network access
  3. Rapid elasticity Correct answer.
  4. Multi-tenancy

Explanation

Rapid elasticity is the ability to scale resources outward and inward automatically as demand changes. Multi-tenancy concerns resource sharing, measured service concerns metering, and broad network access concerns connectivity.

Question 5Cloud Computing Fundamentals and Alibaba Cloud Overview

Which Alibaba Cloud service is a fully managed relational database compatible with MySQL?

  1. Table Store (Tablestore)
  2. ApsaraDB for Redis
  3. ApsaraDB RDS for MySQL Correct answer.
  4. Data Transmission Service (DTS)

Explanation

ApsaraDB RDS for MySQL is the managed relational database offering built around MySQL compatibility. Redis is an in-memory key-value store, Tablestore is a wide-column NoSQL store, and DTS is a data migration and synchronization tool.

Question 6Cloud Computing Fundamentals and Alibaba Cloud Overview

Which Alibaba Cloud service is the primary choice for storing and retrieving unstructured objects such as images and backups?

  1. Object Storage Service (OSS) Correct answer.
  2. Apsara File Storage NAS
  3. Elastic Compute Service (ECS)
  4. Cloud Disk Service

Explanation

OSS is Alibaba Cloud's object storage service, designed for unstructured data accessed over HTTP APIs. Cloud disks are block storage attached to ECS, NAS provides shared file systems, and ECS is compute.

Question 7Cloud Computing Fundamentals and Alibaba Cloud Overview

What is a Region in Alibaba Cloud's global infrastructure?

  1. A logical grouping of accounts for billing
  2. A single physical data center building
  3. A content delivery edge location
  4. A group of availability zones within a defined geographic area Correct answer.

Explanation

A region is a geographic area containing one or more isolated availability zones that are connected by low-latency networks. A single data center is smaller than a region, account groupings are organizational, and edge locations belong to CDN infrastructure.

Question 8Cloud Computing Fundamentals and Alibaba Cloud Overview

Which Alibaba Cloud offering provides a managed Kubernetes environment for orchestrating containers?

  1. Elastic Container Instance (ECI)
  2. Function Compute
  3. Container Service for Kubernetes (ACK) Correct answer.
  4. Resource Access Management (RAM)

Explanation

ACK is the managed Kubernetes service that handles control-plane operations while users run containerized workloads. Function Compute is event-driven serverless compute, ECI runs individual containers without clusters, and RAM manages identities and permissions.

Question 9Cloud Computing Fundamentals and Alibaba Cloud Overview

A company runs a web application on ECS instances across multiple availability zones. What is the primary benefit of this deployment pattern?

  1. It reduces the per-instance price of ECS
  2. It removes the need for backups
  3. It eliminates the need for a load balancer
  4. It improves availability if one zone fails Correct answer.

Explanation

Availability zones are isolated from one another, so distributing instances across zones keeps the application running if a single zone experiences a failure. Pricing and backup obligations are unaffected, and traffic still needs distribution.

Question 10Cloud Computing Fundamentals and Alibaba Cloud Overview

A startup wants to pay only for the compute capacity it consumes each hour with no long-term commitment. Which ECS billing method fits best?

  1. Subscription
  2. Pay-as-you-go Correct answer.
  3. Savings plan
  4. Reserved instance

Explanation

Pay-as-you-go bills ECS resources by actual usage with no upfront commitment, which suits unpredictable or short-lived workloads. Subscription and reserved options trade commitment for discounts and are less flexible.

Question 11Cloud Computing Fundamentals and Alibaba Cloud Overview

Which Alibaba Cloud service provides centralized identity and permission management for cloud resources?

  1. CloudMonitor
  2. ActionTrail
  3. Virtual Private Cloud (VPC)
  4. Resource Access Management (RAM) Correct answer.

Explanation

RAM controls identities, policies, and permissions for accessing Alibaba Cloud resources. CloudMonitor tracks metrics and alarms, ActionTrail records API activity, and VPC defines network isolation.

Question 12Cloud Computing Fundamentals and Alibaba Cloud Overview

What is the main purpose of a Virtual Private Cloud (VPC) in Alibaba Cloud?

  1. To automatically scale ECS instances
  2. To cache static content close to users
  3. To encrypt objects stored in OSS
  4. To provide a logically isolated network with user-defined subnets and routing Correct answer.

Explanation

A VPC creates a private, logically isolated network in which users define IP ranges, subnets, route tables, and gateways. Content caching is done by CDN, autoscaling by Auto Scaling, and object encryption by OSS features.

Question 13Cloud Computing Fundamentals and Alibaba Cloud Overview

A media company wants to deliver video files to users worldwide with low latency by caching content at edge nodes. Which Alibaba Cloud service should it use?

  1. Server Load Balancer (SLB)
  2. Alibaba Cloud CDN Correct answer.
  3. Smart Access Gateway
  4. Express Connect

Explanation

CDN caches content at globally distributed edge nodes so users are served from a nearby location. SLB distributes traffic within a region, Express Connect links on-premises networks to the cloud, and Smart Access Gateway connects branch offices.

Question 14Cloud Computing Fundamentals and Alibaba Cloud Overview

Which Alibaba Cloud service is designed to automatically adjust ECS instance count based on demand?

  1. Operation Orchestration Service (OOS)
  2. Auto Scaling Correct answer.
  3. Cloud Config
  4. Resource Orchestration Service (ROS)

Explanation

Auto Scaling adds or removes ECS instances according to scaling rules and schedules. ROS provisions infrastructure as code, Cloud Config evaluates resource compliance, and OOS automates operational tasks.

Question 15Cloud Computing Fundamentals and Alibaba Cloud Overview

Which statement accurately distinguishes horizontal scaling from vertical scaling?

  1. Horizontal scaling only applies to databases; vertical scaling only applies to web servers
  2. Horizontal scaling requires downtime; vertical scaling never does
  3. Horizontal scaling increases instance size; vertical scaling adds more instances
  4. Horizontal scaling adds more instances; vertical scaling increases the size of an existing instance Correct answer.

Explanation

Horizontal scaling, or scaling out, adds more nodes to share the load, while vertical scaling, or scaling up, gives an existing node more CPU, memory, or other resources. Both apply across workload types, and either can involve disruption depending on implementation.

Question 16Cloud Computing Fundamentals and Alibaba Cloud Overview

An application must tolerate the failure of an entire data center without losing data. Which design choice best meets this requirement?

  1. Replicate data and instances across multiple availability zones in a region Correct answer.
  2. Store all data on one Cloud Disk with RAID 1
  3. Deploy all instances in one availability zone with daily snapshots
  4. Use a single large ECS instance with high availability SLA

Explanation

Availability zones are physically separated within a region, so cross-zone replication allows continued operation when one zone fails. Single-zone deployments, single instances, and local RAID all fail together with their host facility.

Question 17Cloud Computing Fundamentals and Alibaba Cloud Overview

Which Alibaba Cloud service provides monitoring metrics and alarm rules for cloud resources?

  1. ActionTrail
  2. Log Service (SLS)
  3. Resource Access Management (RAM)
  4. CloudMonitor Correct answer.

Explanation

CloudMonitor collects metrics from Alibaba Cloud resources, displays dashboards, and triggers alarms. ActionTrail audits API calls, SLS centralizes log data, and RAM manages permissions.

Question 18Cloud Computing Fundamentals and Alibaba Cloud Overview

What is the primary role of a Server Load Balancer (SLB) in a cloud architecture?

  1. To resolve domain names to IP addresses
  2. To encrypt traffic between the client and the server
  3. To store session data persistently
  4. To distribute incoming requests across multiple backend servers Correct answer.

Explanation

SLB accepts client traffic and forwards it to a pool of backend servers according to configured rules, improving availability and utilization. Encryption, persistent session storage, and DNS resolution are handled by other services.

Question 19Cloud Computing Fundamentals and Alibaba Cloud Overview

A company must keep its database on-premises but wants a private, dedicated network link to Alibaba Cloud instead of using the public internet. Which service should it choose?

  1. Express Connect Correct answer.
  2. Smart Access Gateway
  3. VPN Gateway
  4. NAT Gateway

Explanation

Express Connect provides a dedicated private physical connection between an on-premises data center and Alibaba Cloud, avoiding public internet paths. VPN Gateway tunnels over the internet, Smart Access Gateway targets branch connectivity, and NAT Gateway provides outbound internet access for VPC resources.

Question 20Cloud Computing Fundamentals and Alibaba Cloud Overview

Which Alibaba Cloud database service is an in-memory key-value store commonly used for caching and session management?

  1. PolarDB-O
  2. ApsaraDB RDS for PostgreSQL
  3. ApsaraDB for Redis Correct answer.
  4. AnalyticDB

Explanation

ApsaraDB for Redis is an in-memory data store suited to caching, session state, and low-latency lookups. RDS for PostgreSQL and PolarDB-O are relational engines, and AnalyticDB is oriented toward analytical processing.

Question 21Cloud Computing Fundamentals and Alibaba Cloud Overview

A team needs to run code in response to OSS object-upload events without managing any servers. Which Alibaba Cloud service is the most direct fit?

  1. Elastic Compute Service (ECS)
  2. Function Compute Correct answer.
  3. Container Service for Kubernetes (ACK)
  4. ApsaraDB RDS

Explanation

Function Compute is an event-driven serverless compute service that can be triggered by events such as OSS uploads, with no server management. ECS and ACK require managing infrastructure, and RDS is a database.

Question 22Cloud Computing Fundamentals and Alibaba Cloud Overview

Which statement correctly describes the relationship between Alibaba Cloud regions and availability zones?

  1. Regions are only used for CDN edge caching
  2. A region contains multiple availability zones that are isolated from each other Correct answer.
  3. Each availability zone contains multiple regions
  4. Availability zones and regions are the same concept

Explanation

A region is a geographic area made up of several availability zones, each with independent power and network infrastructure. Zones are smaller than regions, the two are distinct concepts, and CDN edge nodes are separate from regions.

Question 23Cloud Computing Fundamentals and Alibaba Cloud Overview

An application running in a VPC needs to download software patches from the internet, but its ECS instances have no public IP addresses. Which component enables this outbound access?

  1. A NAT Gateway in the VPC Correct answer.
  2. A second VPC peering connection
  3. An SLB with a public IP address
  4. An OSS bucket policy

Explanation

A NAT Gateway lets instances without public IPs initiate outbound connections to the internet while remaining unreachable from outside. Peering links VPCs, SLB distributes inbound traffic, and bucket policies govern OSS access.

Question 24Cloud Computing Fundamentals and Alibaba Cloud Overview

A company wants to run a stateless web tier that can recover automatically from instance failure with minimal operational effort. Which combination best achieves this?

  1. An SLB in front of an Auto Scaling group of ECS instances across zones Correct answer.
  2. A single ECS instance with a manual snapshot schedule
  3. A standalone Cloud Disk attached to a fixed instance
  4. One large ECS instance with a public IP and no monitoring

Explanation

Combining a load balancer, an Auto Scaling group, and multi-zone placement lets unhealthy instances be replaced and traffic rerouted automatically. The other options rely on single points of failure or manual recovery.

Question 25Cloud Computing Fundamentals and Alibaba Cloud Overview

Which statement best explains why measured service supports cost optimization in cloud computing?

  1. It removes the need to monitor resource utilization
  2. It allows resources to be metered and billed by consumption so unused capacity can be released Correct answer.
  3. It guarantees a fixed monthly bill regardless of usage
  4. It requires prepayment for all resources

Explanation

Measured service means usage is metered, so costs track actual consumption and teams can reduce spend by rightsizing or releasing idle resources. It does not fix bills, mandate prepayment, or eliminate the need for monitoring.

Question 26Cloud Computing Fundamentals and Alibaba Cloud Overview

Which characteristic of cloud computing describes the provider's ability to pool computing resources to serve multiple customers from shared physical infrastructure?

  1. Resource pooling Correct answer.
  2. Measured service
  3. Broad network access
  4. Rapid elasticity

Explanation

Resource pooling means the provider serves many tenants from a shared pool of physical and virtual resources, assigning and reassigning capacity dynamically. The customer generally has no knowledge of or control over the exact location of the resources.

Question 27Cloud Computing Fundamentals and Alibaba Cloud Overview

A company is comparing deployment models and wants its applications to run on infrastructure dedicated to a single organization while still being hosted and managed remotely by a cloud provider. Which deployment model fits this requirement?

  1. Public cloud
  2. Community cloud
  3. Hybrid cloud
  4. Private cloud Correct answer.

Explanation

A private cloud provisions infrastructure for exclusive use by a single organization, and it may be operated by the organization or by a third party on its behalf. Exclusivity of use is the defining property, not the physical location or ownership of the hardware.

Question 28Cloud Computing Fundamentals and Alibaba Cloud Overview

An architect is choosing between block storage and object storage for a workload. Which workload characteristic most strongly favors block storage?

  1. Content is accessed over HTTP by many concurrent internet clients
  2. Objects are addressed by a globally unique key rather than by a path
  3. Files are retained for years and rarely read after being written
  4. Data must be mounted as a volume and modified in place by an operating system Correct answer.

Explanation

Block storage presents raw volumes that an operating system formats with a file system and reads or writes in place, which suits databases and boot disks. Object storage instead manages whole objects through an API and is optimized for scale and durability rather than in-place modification.

Question 29Cloud Computing Fundamentals and Alibaba Cloud Overview

Which statement best describes the shared responsibility model as applied to infrastructure as a service?

  1. The customer is responsible for physical security of the data center hosting its instances
  2. The provider is responsible for securing all layers, including guest operating systems and application data
  3. The provider secures the physical facilities while the customer secures everything running above the virtualization layer Correct answer.
  4. Responsibility is split so that the customer secures the hypervisor and the provider secures the guest OS

Explanation

Under IaaS the provider owns security of the facilities, hardware, and virtualization layer, while the customer owns the guest operating system, middleware, applications, and data. Responsibility shifts toward the provider as the service model moves toward managed platform and software offerings.

Question 30Cloud Computing Fundamentals and Alibaba Cloud Overview

A team must choose between deploying an application on virtual machines and refactoring it for a serverless function platform. Which consideration most directly argues against the serverless option?

  1. The workload is a long-running process that holds state in memory for many hours Correct answer.
  2. The application is a short-lived task triggered by file upload events
  3. The application receives traffic in unpredictable bursts throughout the day
  4. The application must scale to zero when it is idle to control cost

Explanation

Function platforms impose execution time limits and favor stateless, short-lived invocations, so a process that must keep state in memory for hours fits poorly. Bursty traffic, scale-to-zero economics, and event-triggered short tasks are all strengths of serverless rather than objections to it.

Question 31Elastic Compute Service (ECS)

Which Alibaba Cloud service is primarily responsible for providing scalable virtual computing resources?

  1. ApsaraDB for RDS
  2. Elastic Compute Service (ECS) Correct answer.
  3. Server Load Balancer (SLB)
  4. Object Storage Service (OSS)

Explanation

ECS is the core IaaS offering that provides virtual machines with configurable CPU, memory, and storage. OSS is object storage, RDS is a managed database, and SLB distributes traffic.

Question 32Elastic Compute Service (ECS)

Which ECS instance type family is optimized for memory-intensive workloads such as large databases and caching?

  1. Compute-optimized (c-series)
  2. Shared (t-series)
  3. Memory-optimized (r-series) Correct answer.
  4. General-purpose (g-series)

Explanation

Memory-optimized instances provide a higher memory-to-vCPU ratio, making them suitable for memory-intensive applications. General-purpose balances compute and memory, compute-optimized favors CPU, and shared instances are burstable.

Question 33Elastic Compute Service (ECS)

What is the primary purpose of an ECS security group?

  1. To automatically scale the number of ECS instances
  2. To encrypt data at rest on ECS disks
  3. To monitor the performance of ECS instances
  4. To act as a virtual firewall controlling inbound and outbound traffic Correct answer.

Explanation

Security groups are stateful virtual firewalls that control network access to and from ECS instances by allowing or denying traffic based on rules. They do not handle encryption, monitoring, or scaling.

Question 34Elastic Compute Service (ECS)

Which statement accurately describes the relationship between an ECS instance and a disk?

  1. A disk can be shared across instances only if it is a system disk.
  2. A disk can be attached to multiple instances simultaneously in all cases.
  3. A disk can be attached to only one instance at a time, but can be detached and reattached. Correct answer.
  4. A disk is permanently bound to the instance it was created with and cannot be detached.

Explanation

A cloud disk is attached to a single ECS instance at any given time, but it can be detached and attached to another instance within the same zone. Multi-attach is only available for specific shared block storage products, not standard cloud disks.

Question 35Elastic Compute Service (ECS)

What is the function of an ECS image?

  1. To define network access rules for instances
  2. To provide a template for creating new ECS instances with a preconfigured operating system and software Correct answer.
  3. To store backups of ECS data
  4. To distribute incoming traffic across multiple instances

Explanation

An image is a template that includes the operating system, configuration, and optionally applications, used to launch new instances consistently. Backups are stored as snapshots, traffic distribution is done by SLB, and access rules are defined by security groups.

Question 36Elastic Compute Service (ECS)

Which Alibaba Cloud service is used to automatically adjust the number of ECS instances based on demand?

  1. Auto Scaling Correct answer.
  2. Virtual Private Cloud (VPC)
  3. Resource Access Management (RAM)
  4. CloudMonitor

Explanation

Auto Scaling automatically adjusts computing resources based on scaling policies and schedules. RAM manages permissions, CloudMonitor collects metrics, and VPC provides isolated networks.

Question 37Elastic Compute Service (ECS)

What is the default network access behavior for a newly created security group?

  1. All inbound and outbound traffic is denied by default.
  2. All inbound traffic is allowed and all outbound traffic is denied by default.
  3. All inbound and outbound traffic is allowed by default.
  4. All inbound traffic is denied and all outbound traffic is allowed by default. Correct answer.

Explanation

By default, a new security group denies all inbound traffic and allows all outbound traffic. Users must explicitly add inbound rules to permit desired traffic.

Question 38Elastic Compute Service (ECS)

Which of the following is a valid method to connect to a Linux ECS instance for remote administration?

  1. FTP
  2. Remote Desktop Protocol (RDP)
  3. SSH Correct answer.
  4. Telnet

Explanation

SSH is the standard secure protocol for remote command-line access to Linux instances. RDP is for Windows, Telnet is insecure and typically disabled, and FTP is for file transfer.

Question 39Elastic Compute Service (ECS)

A user needs to deploy a stateful web application that requires block storage with high IOPS and low latency. Which ECS disk type should they choose?

  1. Standard cloud disk
  2. ESSD cloud disk Correct answer.
  3. Local SSD disk
  4. Ultra cloud disk

Explanation

ESSD (Enhanced SSD) cloud disks provide high random IOPS and low latency, suitable for stateful, I/O-intensive applications. Standard disks are cost-effective but slower, ultra disks offer balanced performance, and local SSD is ephemeral.

Question 40Elastic Compute Service (ECS)

An application running on an ECS instance needs to access an OSS bucket securely without embedding AccessKeys in code. What is the best practice?

  1. Use an instance RAM role to grant permissions to the instance. Correct answer.
  2. Store AccessKeys in a configuration file on the instance.
  3. Create a RAM user and hardcode the AccessKey in the application.
  4. Disable security groups to allow unrestricted access to OSS.

Explanation

An instance RAM role allows the ECS instance to obtain temporary credentials automatically, eliminating the need to store long-term AccessKeys. This follows the principle of least privilege and improves security.

Question 41Elastic Compute Service (ECS)

A company wants to ensure that an ECS instance can only be accessed from a specific IP range on port 22. How should they configure the security group?

  1. Add an inbound rule allowing all traffic from the specific IP range.
  2. Add an outbound rule allowing TCP port 22 to the specific IP range.
  3. Add an inbound rule denying TCP port 22 from all IPs.
  4. Add an inbound rule allowing TCP port 22 from the specific IP range. Correct answer.

Explanation

To control SSH access, an inbound rule permitting TCP port 22 from the trusted IP range is required. Security groups are stateful, so return traffic is automatically allowed.

Question 42Elastic Compute Service (ECS)

A user wants to create a custom image from an existing ECS instance to launch new instances with the same configuration. What must be done first?

  1. Create a snapshot of the system disk.
  2. Detach all disks.
  3. Change the instance type.
  4. Stop the instance. Correct answer.

Explanation

To create a custom image from an instance, the instance must be stopped to ensure data consistency. Creating a snapshot is part of the process but stopping is a prerequisite.

Question 43Elastic Compute Service (ECS)

Which scaling policy type in Auto Scaling adjusts the number of instances based on a specified schedule?

  1. Fixed scaling
  2. Manual scaling
  3. Scheduled scaling Correct answer.
  4. Dynamic scaling

Explanation

Scheduled scaling allows you to set the desired number of instances at specific times, useful for predictable load patterns. Dynamic scaling reacts to metrics, fixed scaling maintains a constant count, and manual scaling requires user intervention.

Question 44Elastic Compute Service (ECS)

What is the purpose of a placement group in ECS?

  1. To control the physical distribution of instances to reduce correlated failures or improve network performance Correct answer.
  2. To group instances for billing purposes
  3. To apply security group rules to multiple instances at once
  4. To automatically create snapshots of instances

Explanation

Placement groups influence how instances are placed on physical hardware to either spread them for fault tolerance or pack them for low-latency networking. They are not for billing, security, or backup.

Question 45Elastic Compute Service (ECS)

A user needs to allow an ECS instance to communicate with another instance in a different security group within the same VPC. What is the recommended approach?

  1. Assign both instances to the same public IP.
  2. Add the private IP of the target instance to the source security group's outbound rules.
  3. Disable both security groups.
  4. Add a rule in the target security group allowing traffic from the source security group. Correct answer.

Explanation

Security groups can reference other security groups as sources in inbound rules, which is more maintainable than IP-based rules. This allows all instances in the source group to communicate with the target group.

Question 46Elastic Compute Service (ECS)

Which ECS instance purchasing option is most cost-effective for a workload that runs continuously for three years with predictable usage?

  1. Spot instance
  2. Preemptible instance
  3. Subscription Correct answer.
  4. Pay-as-you-go

Explanation

Subscription (prepaid) instances offer significant discounts for long-term commitments. Pay-as-you-go is flexible but more expensive, and spot/preemptible instances can be reclaimed and are not suitable for stable long-term workloads.

Question 47Elastic Compute Service (ECS)

An ECS instance is experiencing high CPU utilization due to a sudden traffic spike. Which service can automatically add more instances to handle the load?

  1. Server Load Balancer
  2. Auto Scaling Correct answer.
  3. CloudMonitor
  4. VPN Gateway

Explanation

Auto Scaling can monitor metrics and automatically scale out instances when thresholds are breached. SLB distributes traffic, CloudMonitor only monitors, and VPN Gateway provides secure connectivity.

Question 48Elastic Compute Service (ECS)

What is the maximum number of security groups that can be applied to a single ECS instance?

  1. 10
  2. 20
  3. 5 Correct answer.
  4. 1

Explanation

An ECS instance can be associated with up to 5 security groups, which helps manage rules collectively. This limit is a quota that can be increased via support request.

Question 49Elastic Compute Service (ECS)

A user wants to deploy a Windows ECS instance and connect to it remotely. Which port must be allowed in the security group?

  1. TCP 443
  2. TCP 80
  3. TCP 3389 Correct answer.
  4. TCP 22

Explanation

Windows instances use RDP, which listens on TCP port 3389. Port 22 is for SSH, and ports 80 and 443 are for HTTP and HTTPS.

Question 50Elastic Compute Service (ECS)

Which statement about ECS instance metadata is correct?

  1. It contains the instance's public IP address but not its private IP address.
  2. It is only available through the Alibaba Cloud console.
  3. It can be accessed from within the instance via a special IP address. Correct answer.
  4. It requires an additional subscription.

Explanation

Instance metadata is accessible from within the instance at the link-local address 100.100.100.200, providing information such as instance ID, region, and user data. It is free and does not require console access.