I85PREP
⌘ K
ACA CCO study materials
ACA CCO study resources

ACA CCO practice questions

One question at a time. Build your ACA CCO understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Cloud Computing Fundamentals

Which cloud characteristic describes a provider automatically scaling resources up or down to match demand without manual intervention?

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

Explanation

Rapid elasticity is the property by which capacity can be provisioned and released automatically to scale with demand, appearing nearly unlimited to the consumer. The other options describe metering, multi-tenancy, and network reachability rather than dynamic scaling.

Question 2Cloud Computing Fundamentals

In the NIST service model definitions, which model gives the consumer the greatest level of control over the operating system and runtime?

  1. IaaS Correct answer.
  2. FaaS
  3. PaaS
  4. SaaS

Explanation

IaaS provides virtualized compute, storage, and networking on which the consumer installs and manages the OS, runtime, and applications. Higher-level models abstract more of the stack away from the consumer.

Question 3Cloud Computing Fundamentals

A company wants to move workloads between its own data center and a public cloud using common management and orchestration tools. Which deployment model does this describe?

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

Explanation

A hybrid cloud combines two or more distinct deployment models (such as private and public) bound by technology enabling data and application portability. Portability and shared orchestration are the defining traits here.

Question 4Cloud Computing Fundamentals

Which term describes the ability of a system to continue operating correctly despite the failure of some of its components?

  1. Fault tolerance Correct answer.
  2. Availability
  3. Scalability
  4. Durability

Explanation

Fault tolerance is the capacity to keep functioning when components fail, typically through redundancy. Availability measures uptime as perceived by users, and durability concerns data persistence.

Question 5Cloud Computing Fundamentals

What is the primary purpose of a content delivery network (CDN) in a cloud architecture?

  1. To cache content at edge locations near users Correct answer.
  2. To encrypt data at rest in object storage
  3. To schedule batch jobs across regions
  4. To provide identity federation across tenants

Explanation

A CDN caches copies of content at geographically distributed edge nodes so requests are served closer to users, reducing latency and origin load. Encryption, identity, and job scheduling are separate concerns.

Question 6Cloud Computing Fundamentals

Which statement best describes serverless computing (FaaS)?

  1. The provider guarantees a fixed number of always-running instances.
  2. The consumer rents dedicated physical servers with root access.
  3. The provider manages servers and the consumer is billed per request and execution time. Correct answer.
  4. The consumer manages virtual machines and patches the guest OS.

Explanation

In FaaS the provider fully manages the underlying servers and scales execution on demand, and billing is based on invocations and compute duration. Consumers do not provision or patch servers.

Question 7Cloud Computing Fundamentals

Which cloud storage category is best suited for storing millions of unstructured objects accessed by HTTP APIs?

  1. Archive tape
  2. Block storage
  3. Object storage Correct answer.
  4. File storage

Explanation

Object storage manages data as discrete objects with metadata in flat namespaces, accessed via HTTP APIs, and scales to very large numbers of unstructured items. Block and file storage present different access semantics.

Question 8Cloud Computing Fundamentals

What does the shared responsibility model define in cloud security?

  1. Which regions are available to each customer tier
  2. How costs are split between provider and customer
  3. Which security tasks belong to the provider versus the customer Correct answer.
  4. How data is replicated across availability zones

Explanation

The shared responsibility model allocates security and compliance duties between the cloud provider and the customer, with the split varying by service model. It is not about billing, replication, or regional availability.

Question 9Cloud Computing Fundamentals

A team needs block-level storage that can be attached to a single virtual machine for a transactional database. Which option fits best?

  1. Persistent block volume Correct answer.
  2. Object storage bucket
  3. Managed file share
  4. Serverless function store

Explanation

Databases requiring low-latency block device semantics are best served by persistent block volumes attached to compute instances. Object and file storage do not provide raw block devices.

Question 10Cloud Computing Fundamentals

Which design choice most directly improves the availability of a stateless web tier across a region?

  1. Increasing the instance size of a single server
  2. Deploying instances in multiple availability zones behind a load balancer Correct answer.
  3. Pinning all traffic to one zone for lower latency
  4. Storing session state on local instance disks

Explanation

Spreading stateless instances across independent availability zones behind a load balancer removes single points of failure and lets traffic shift when a zone fails. Vertical scaling and local state increase coupling and risk.

Question 11Cloud Computing Fundamentals

An application experiences unpredictable spikes and idle periods. Which purchasing approach minimizes cost while preserving the ability to scale?

  1. Dedicated hosts sized for peak
  2. Long-term committed contracts at average load
  3. On-demand or auto-scaled capacity Correct answer.
  4. Reserved capacity for peak load

Explanation

On-demand capacity combined with auto-scaling matches spend to actual usage during unpredictable demand. Committing capacity to peak or average load wastes money during idle periods.

Question 12Cloud Computing Fundamentals

Which action best reduces the blast radius of a compromised workload credential?

  1. Embedding long-lived keys in source code
  2. Granting the workload broad administrative permissions
  3. Sharing one credential across all workloads
  4. Scoping permissions to least privilege and rotating credentials Correct answer.

Explanation

Least-privilege scoping limits what a compromised credential can do, and rotation shortens its useful lifetime. Broad, shared, or hard-coded credentials enlarge the impact of a leak.

Question 13Cloud Computing Fundamentals

A company must keep certain regulated data within national borders. Which cloud capability addresses this requirement?

  1. Enabling multi-factor authentication
  2. Using a content delivery network
  3. Choosing a region in the required country Correct answer.
  4. Adopting a serverless architecture

Explanation

Regional selection lets an organization place data and processing in a specific geographic jurisdiction to satisfy residency rules. The other choices affect security or performance, not data location.

Question 14Cloud Computing Fundamentals

Which characteristic distinguishes horizontal scaling from vertical scaling?

  1. Horizontal scaling requires downtime; vertical scaling never does.
  2. Horizontal scaling adds CPU and memory to one server; vertical scaling adds instances.
  3. Horizontal scaling only applies to databases; vertical scaling only to web servers.
  4. Horizontal scaling adds more instances; vertical scaling adds resources to one instance. Correct answer.

Explanation

Horizontal (scale out) scaling increases the count of nodes, while vertical (scale up) scaling increases the size of a single node. The other statements invert or misstate these definitions.

Question 15Cloud Computing Fundamentals

What is the main benefit of infrastructure as code for cloud provisioning?

  1. It removes the need for any access controls
  2. It makes environments reproducible and version-controlled Correct answer.
  3. It guarantees zero cost overruns
  4. It eliminates the need for testing

Explanation

Declaring infrastructure in version-controlled files makes environments reproducible and auditable and supports consistent change management. It does not remove security controls, guarantee costs, or replace testing.

Question 16Cloud Computing Fundamentals

A workload must survive the loss of an entire data center. Which approach satisfies this requirement?

  1. A daily snapshot to local storage
  2. Backups stored on the same host
  3. Replication across multiple availability zones Correct answer.
  4. A single instance with a large disk

Explanation

Availability zones are isolated data centers within a region, so replicating across zones lets a workload continue if one facility is lost. Local backups and single instances share the same failure domain.

Question 17Cloud Computing Fundamentals

Which statement accurately contrasts containers with virtual machines?

  1. Containers include a full guest OS; VMs share the host kernel.
  2. Containers provide stronger isolation than VMs by default.
  3. Containers share the host kernel; VMs each run a full guest OS. Correct answer.
  4. Containers cannot be orchestrated; VMs can.

Explanation

Containers package an application with its dependencies and share the host operating system kernel, while virtual machines each include a complete guest OS managed by a hypervisor. This makes containers lighter but generally less isolated than VMs.

Question 18Cloud Computing Fundamentals

What does an availability zone represent within a cloud region?

  1. A billing tier for discounted usage
  2. A single physical server rack in a shared hall
  3. A network peering connection between regions
  4. A separate isolated data center location within the region Correct answer.

Explanation

Regions are composed of multiple availability zones, each an isolated facility with independent power and networking, so failures are unlikely to affect several at once. They are not billing constructs or single racks.

Question 19Cloud Computing Fundamentals

An application reads the same small configuration dataset millions of times per hour. Which change most reduces database load?

  1. Enabling slower storage volumes
  2. Adding an in-memory cache in front of the database Correct answer.
  3. Increasing the database instance size
  4. Sharding the configuration table by region

Explanation

Caching frequently read, rarely changing data in memory absorbs repeated reads and shields the database. Vertical scaling and sharding add cost and complexity without eliminating repeated reads.

Question 20Cloud Computing Fundamentals

Which practice best supports the principle of least privilege for human users in a cloud environment?

  1. Disabling audit logging to reduce noise
  2. Using role-based access with time-bound elevation Correct answer.
  3. Sharing one service account among the team
  4. Assigning a single administrator role to all staff

Explanation

Role-based access limits standing permissions to what each role requires, and time-bound elevation grants extra rights only when needed. Broad shared accounts and disabled logging undermine accountability.

Question 21Cloud Computing Fundamentals

What is the key distinction between a public cloud and a private cloud?

  1. Private cloud is dedicated to one organization while public cloud is shared Correct answer.
  2. Public cloud cannot offer security controls
  3. Public cloud is always cheaper than private cloud
  4. Private cloud cannot be virtualized

Explanation

The defining difference is tenancy: a private cloud is provisioned for exclusive use by a single organization, whereas a public cloud serves multiple customers from shared infrastructure. Cost, security, and virtualization are not defining distinctions.

Question 22Cloud Computing Fundamentals

A service must process messages asynchronously so that producers are not blocked when consumers are slow. Which architectural component addresses this?

  1. A CDN edge cache
  2. A message queue between producers and consumers Correct answer.
  3. A shared relational database table
  4. A synchronous REST call to consumers

Explanation

A message queue decouples producers from consumers by buffering messages, letting producers continue while consumers process at their own pace. Synchronous calls and shared tables couple the parties and propagate slowness.

Question 23Cloud Computing Fundamentals

An organization wants to reduce the risk that a single region-wide outage halts its service. Which strategy best addresses this?

  1. Auto-scaling confined to one availability zone
  2. Daily backups to the same region
  3. Multi-region active-active deployment with data replication Correct answer.
  4. Single-region deployment with larger instances

Explanation

Serving traffic from multiple regions with replicated data lets the service continue if an entire region becomes unavailable. Larger instances, same-region backups, and single-zone scaling all remain within the failed region.

Question 24Cloud Computing Fundamentals

Which statement about the recovery point objective (RPO) is correct?

  1. RPO specifies the maximum acceptable downtime after a failure
  2. RPO is the number of replicas required for durability
  3. RPO specifies the maximum acceptable data loss measured in time Correct answer.
  4. RPO is the cost of restoring backups

Explanation

RPO defines how much data, expressed as a time window, an organization can afford to lose, which drives backup and replication frequency. Downtime tolerance is the recovery time objective, not the RPO.

Question 25Cloud Computing Fundamentals

A team is designing for bursty traffic with a strict budget. Which combination best balances cost and responsiveness?

  1. Always-on maximum-capacity instances
  2. Auto-scaling on-demand instances with a small reserved baseline Correct answer.
  3. Dedicated hosts for every environment
  4. Reserved instances sized for peak traffic

Explanation

A small reserved baseline covers steady load at lower cost, while on-demand auto-scaling absorbs bursts only when needed. Sizing everything for peak wastes spend during idle periods.

Question 26Cloud Computing Fundamentals

Which cloud service model provides a platform for developers to deploy applications without managing the underlying operating system or runtime?

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

Explanation

PaaS abstracts the infrastructure and runtime, allowing developers to focus on code. IaaS provides raw compute, storage, and networking, while SaaS delivers complete applications. FaaS is a subset of serverless computing focused on event-driven functions.

Question 27Cloud Computing Fundamentals

Which cloud characteristic allows customers to automatically provision resources on demand without human intervention?

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

Explanation

Rapid elasticity enables automatic scaling of resources up or down based on demand. Broad network access refers to availability over the network, measured service to pay-per-use billing, and resource pooling to multi-tenant infrastructure.

Question 28Cloud Computing Fundamentals

What is the primary purpose of a content delivery network (CDN) in cloud architecture?

  1. To automatically scale compute instances based on load
  2. To encrypt data at rest in cloud storage
  3. To cache content at edge locations closer to users Correct answer.
  4. To provide a dedicated private network connection to the cloud

Explanation

A CDN caches content at geographically distributed edge locations to reduce latency and offload origin servers. Encryption at rest is handled by storage services, private connectivity by dedicated network services, and auto-scaling by compute services.

Question 29Cloud Computing Fundamentals

Which cloud deployment model combines public cloud services with on-premises infrastructure?

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

Explanation

A hybrid cloud integrates public cloud resources with private or on-premises infrastructure, allowing data and applications to move between them. Community cloud is shared by several organizations, private cloud is dedicated to one organization, and public cloud is shared multi-tenant infrastructure.

Question 30Cloud Computing Fundamentals

What does the term 'multi-tenancy' mean in cloud computing?

  1. Applications are deployed across multiple regions for redundancy
  2. Multiple customers share the same physical infrastructure while their data remains isolated Correct answer.
  3. Each customer is assigned a dedicated physical server
  4. A single customer uses multiple cloud providers simultaneously

Explanation

Multi-tenancy allows cloud providers to serve many customers from shared physical resources, achieving economies of scale while maintaining logical isolation. Using multiple providers is multi-cloud, dedicated servers are single-tenant, and multi-region deployment is a resilience strategy.

Question 31Cloud Computing Fundamentals

Which statement best describes the role of a hypervisor in cloud virtualization?

  1. It provides a graphical interface for managing cloud resources
  2. It automatically scales the number of virtual machines based on demand
  3. It encrypts network traffic between cloud regions
  4. It abstracts physical hardware and allocates resources to virtual machines Correct answer.

Explanation

A hypervisor, or virtual machine monitor, creates and runs virtual machines by abstracting the underlying physical hardware and partitioning resources. It does not provide a management GUI, encrypt network traffic, or handle auto-scaling.

Question 32Cloud Computing Fundamentals

A company wants to migrate a legacy application to the cloud with minimal changes. Which migration strategy is most appropriate?

  1. Lift and shift Correct answer.
  2. Replatform
  3. Retire
  4. Re-architect

Explanation

Lift and shift (rehosting) moves applications to the cloud with little or no modification, making it the least disruptive for legacy apps. Re-architect and replatform involve significant changes, and retire means decommissioning the application.

Question 33Cloud Computing Fundamentals

Which cloud networking component is used to isolate resources within a virtual network?

  1. Load balancer
  2. Route table
  3. Subnet Correct answer.
  4. Security group

Explanation

A subnet divides a virtual network into smaller, isolated segments, often used to separate public and private resources. Load balancers distribute traffic, security groups act as virtual firewalls, and route tables direct traffic between subnets.

Question 34Cloud Computing Fundamentals

What is the primary benefit of using a managed database service in the cloud?

  1. It guarantees zero downtime for all applications
  2. It provides unlimited storage at no additional cost
  3. It eliminates the need for database schema design
  4. It automatically handles backups, patching, and scaling Correct answer.

Explanation

Managed database services offload operational tasks such as backups, software patching, and scaling to the provider. Schema design remains the customer's responsibility, zero downtime is not guaranteed, and storage costs still apply.

Question 35Cloud Computing Fundamentals

Which cloud concept refers to the ability to recover from a disaster with minimal data loss and downtime?

  1. Fault tolerance
  2. High availability
  3. Disaster recovery Correct answer.
  4. Scalability

Explanation

Disaster recovery focuses on restoring operations after a major disruption, with objectives like RTO and RPO. High availability minimizes downtime from component failures, fault tolerance allows continued operation despite failures, and scalability handles growth.

Question 36Cloud Computing Fundamentals

A company needs to ensure that data stored in the cloud can be recovered to a specific point in time. Which feature should they use?

  1. Versioning Correct answer.
  2. Encryption
  3. Lifecycle policies
  4. Replication

Explanation

Versioning keeps multiple versions of an object, allowing recovery to a previous state. Lifecycle policies automate deletion or archival, replication copies data to another location, and encryption protects data confidentiality.

Question 37Cloud Computing Fundamentals

Which factor most directly affects the cost of cloud computing?

  1. The number of users accessing the application
  2. The programming language used
  3. The amount of resources consumed Correct answer.
  4. The geographic location of the development team

Explanation

Cloud costs are primarily based on resource consumption, such as compute hours, storage, and data transfer. The number of users may influence resource usage but is not the direct billing metric. Location of the team and programming language do not directly affect cost.

Question 38Cloud Computing Fundamentals

Which statement about cloud security is true under the shared responsibility model?

  1. The customer is always responsible for physical security of data centers
  2. Security responsibilities are identical for all service models
  3. The cloud provider is responsible for securing customer data
  4. The provider secures the infrastructure, while the customer secures what they put in the cloud Correct answer.

Explanation

Under the shared responsibility model, the provider manages security of the cloud (infrastructure), and the customer manages security in the cloud (data, applications, access). The provider does not secure customer data, and customer responsibility varies by service model.

Question 39Cloud Computing Fundamentals

Which design pattern is most suitable for decoupling components in a cloud-native application?

  1. Client-server architecture
  2. Monolithic architecture
  3. Peer-to-peer architecture
  4. Event-driven architecture Correct answer.

Explanation

Event-driven architecture uses events and message brokers to decouple producers and consumers, improving scalability and resilience. Monolithic architecture tightly couples components, client-server often creates direct dependencies, and peer-to-peer is not typical for cloud-native decoupling.

Question 40Cloud Computing Fundamentals

A company wants to optimize costs for a workload that runs continuously for three years. Which purchasing option is most cost-effective?

  1. Dedicated hosts
  2. On-demand instances
  3. Spot instances
  4. Reserved instances Correct answer.

Explanation

Reserved instances offer significant discounts for long-term commitments (e.g., one or three years). On-demand is flexible but more expensive, spot instances are cheaper but can be interrupted, and dedicated hosts are for compliance or licensing needs.

Question 41Elastic Compute Service (ECS) Operations

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

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

Explanation

Instance families are named by their primary resource ratio. Memory optimized families provide a higher memory-to-vCPU ratio than general purpose or compute optimized families, making them suitable for memory-bound workloads.

Question 42Elastic Compute Service (ECS) Operations

An application must survive the loss of a single Availability Zone with no manual intervention. Which ECS deployment approach meets this requirement?

  1. Deploy instances on a single dedicated host
  2. Deploy instances across multiple zones behind a Server Load Balancer Correct answer.
  3. Deploy instances in one zone with auto scaling enabled
  4. Deploy all instances in one zone with automatic snapshots

Explanation

Zone-level fault tolerance requires spreading capacity across independent Availability Zones and routing traffic to healthy instances. A load balancer with multi-zone backend instances provides that resilience automatically.

Question 43Elastic Compute Service (ECS) Operations

Which ECS disk category delivers the highest random IOPS and lowest latency for a latency-sensitive database?

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

Explanation

ESSD (Enhanced SSD) is the highest-performance cloud disk category, offering very high IOPS and low latency that scales with capacity and performance level. Ultra disks and standard SSDs sit below it in performance.

Question 44Elastic Compute Service (ECS) Operations

A team wants to reduce compute cost for a batch job that can be interrupted and restarted. Which purchasing model is most appropriate?

  1. Pay-as-you-go instances
  2. Subscription (prepaid) yearly instances
  3. Preemptible (spot) instances Correct answer.
  4. Dedicated hosts

Explanation

Preemptible instances offer large discounts in exchange for the possibility of being reclaimed, which suits fault-tolerant, checkpointed batch workloads. Workloads that cannot tolerate interruption should use other models.

Question 45Elastic Compute Service (ECS) Operations

Which ECS feature lets you define rules that automatically add or remove instances based on metrics such as CPU utilization?

  1. Resource Orchestration Service
  2. Elastic IP address
  3. CloudMonitor alert rules
  4. Auto Scaling Correct answer.

Explanation

Auto Scaling adjusts the number of ECS instances according to scaling rules and policies tied to metrics or schedules. Alert rules and orchestration services do not themselves change instance counts.

Question 46Elastic Compute Service (ECS) Operations

A user needs to log in to a Linux ECS instance without opening port 22 to the internet. What is the recommended approach?

  1. Disable the security group entirely
  2. Use the instance's private IP from a public network
  3. Attach an Elastic IP and allow 0.0.0.0/0 on port 22
  4. Use the ECS console's remote connection (VNC/Workbench) or a bastion host in a private subnet Correct answer.

Explanation

Administrative access should avoid exposing SSH broadly. Console-based remote connection or a bastion host inside the VPC provides controlled access without public exposure of port 22.

Question 47Elastic Compute Service (ECS) Operations

Which component controls inbound and outbound traffic at the instance level in ECS?

  1. Internet NAT gateway
  2. Route table
  3. Security group Correct answer.
  4. VSwitch

Explanation

Security groups act as stateful virtual firewalls attached to instances, controlling allowed inbound and outbound traffic by rule. Route tables and vSwitches handle networking topology, not per-instance filtering.

Question 48Elastic Compute Service (ECS) Operations

What is the primary purpose of an ECS image?

  1. To provide additional IOPS to attached disks
  2. To serve as a template containing the OS and software used to create new instances Correct answer.
  3. To encrypt data at rest on the system disk
  4. To assign public IP addresses to instances

Explanation

An image captures the operating system and installed software and is used as the template when launching instances. It can also be used to replicate environments consistently.

Question 49Elastic Compute Service (ECS) Operations

A snapshot policy is configured on a data disk. What does each snapshot capture?

  1. Only files modified since the last snapshot
  2. The complete state of the disk at the time the snapshot is taken Correct answer.
  3. The security group rules applied to the instance
  4. The instance's memory contents

Explanation

A snapshot is a point-in-time backup of a disk that can be used to restore or clone data. Incremental storage is used behind the scenes, but logically each snapshot represents the disk state at that time.

Question 50Elastic Compute Service (ECS) Operations

An instance in a private vSwitch must download OS updates from the internet. Which configuration enables this?

  1. Attach an additional data disk
  2. Configure a NAT gateway in the VPC and route the private subnet to it Correct answer.
  3. Open all ports in the security group
  4. Assign an Elastic IP to every instance

Explanation

A NAT gateway provides outbound internet access for instances without public IP addresses, keeping them unreachable from the internet. The subnet's route table must direct internet-bound traffic to the NAT gateway.