Amazon AWS DevOps Engineer Professional Exam Prep
AWS DevOps Engineer - Professional (DOP-C02) (Page 18 )

• RPO and RTO definitions:

• Why B and D meet these goals:

• How they complement each other:

• Quick tips:

• ??? AWS CloudFormation ?????? Lambda ???? ???? ??????????? API Gateway ???? ???? ??? ?????????? ???? ???? ????.
• ???????? ????? Lambda ??????? aimmutable ????, ???????? ???? ??? ???? ?????????? ???? ??????? (versions) ????? ????.
• Canary release strategy ?????? ???? ?????? ???????????????? ??????? ??????? ?????? new ??????????? ????? ????, ???????? ???? ???????? ???? ????.
• ??? ????????? ?????????????? ?????????? ???? Lambda ??? ??? API ???? ???? ???????? ???????? ???? ???? ????, ???????? ???? ??????????????? IaC ???????? ????? ????.
• ???????? ????? ??????????, canary ????? ????? ??????? ???????? 100% ?? ???? ???? (promote).

• A: Route 53 failover ?? ???? canary ???? ?????????, gradual traffic shifting ???? ????? ????; ?????? ?????? ???????? DR ????.
• C, D: Elastic Beanstalk ????? OpsWorks ?? serverless-????? ? ??? ??????? ???????????? ???? ?????.

• Prevention costs – costs incurred to stop defects occurring, such as staff training, quality planning and supplier evaluation.
• Appraisal costs – costs of checking whether products meet standards, such as inspection, testing and quality audits.
• Internal failure costs – costs of defects found before delivery to customers, such as scrap, rework and retesting.
• External failure costs – costs of defects found after delivery, such as warranty claims, returns, complaints and product recalls.

• s3:GetObject for the relevant objects
• s3:ListBucket if listing is required
• Appropriate bucket and object resource permissions

• B: Making the bucket public is insecure and unnecessary.
• C: Prompt engineering cannot override AWS IAM or encryption permissions.
• D: Data sensitivity does not determine whether the role can access it.

• The application failing to start or becoming unhealthy
• An incorrect probe path, port, or protocol
• The application needing more startup time
• Dependency or configuration failures
• A liveness probe being too aggressive

bash 
kubectl describe pod <pod-name> 
kubectl logs <pod-name> --previous

• Scale to more replicas: may hide the issue but does not diagnose it.
• Decrease initialDelaySeconds: makes probes run earlier and could worsen startup failures.
• Drain and reboot the node: node metrics are normal, so rebooting is not justified as the first step.

• Employees can work from any location, including remote sites and offices worldwide.
• Login can be relatively seamless after the device is registered.
• It does not require distributing additional physical authentication equipment.

• Geotagging: Identifies location, but location alone is not a strong authentication method and may prevent legitimate remote access.
• Smart cards: Provide strong authentication but require card readers and physical cards, increasing equipment and management requirements.
• Time-based logins: Typically involve one-time codes that users must enter, making the experience less seamless and potentially requiring a token or authenticator app.

• Import: Copies data into the Power BI model. It requires scheduled or manual refresh, so it may not meet the two-minute requirement.
• Live connection: Connects to an existing Power BI semantic model or Analysis Services model; it is not the appropriate choice for connecting directly to the Azure SQL database in this scenario.

• 10 TB with maximum I/O performance: Use EC2 instance store. It provides very high-throughput, low-latency local storage suitable for temporary video-processing data. The application must tolerate data loss because instance store is ephemeral.
• 300 TB of highly durable media: Use Amazon S3, which is designed for highly durable object storage and can scale to this size.
• 900 TB of inactive archival media: Use S3 Glacier, which provides lower-cost storage for data that is rarely accessed.

• A: Amazon EBS offers high performance but is not the best fit for the question’s “maximum possible I/O” requirement compared with local instance store.
• B: Amazon EFS is durable and shared, but is generally more expensive and less suitable for very large archival storage.
• C: Uses EC2 instance store for performance, but incorrectly uses EFS for the 300-TB durable tier and S3 rather than Glacier for archival data.

• The type of change: standard, normal, or emergency
• The risk, impact, and complexity
• The change model being used

• A standard change may be pre-authorized through its change model.
• A normal change may require assessment and approval by an appropriate change authority.
• An emergency change may be authorized by an emergency change authority, often using an expedited process.

• Change authorities are not only needed for emergency changes.
• They are not assigned only when a change is deployed.
• They are not only required for normal changes.

• A — Can help keep costs down and improve quality: The provider may have specialist expertise, efficient systems and economies of scale.
• B — There is a known fee if agreed in advance: A fixed or agreed fee can make costs more predictable and support budgeting.
• C — Allows management to focus on core operations and issues: Senior managers spend less time supervising routine finance processes and more time on strategic matters.

• Increased control: Control may decrease because the activity is performed externally.
• Increased independence: The organisation becomes dependent on the supplier.
• Increased understanding of the outsourcing business: The internal organisation usually has greater business knowledge; the provider may initially lack it.
• Increased confidentiality: Sharing financial information externally may create confidentiality risks.
• Internal expertise improved: Outsourcing can reduce opportunities to develop internal finance skills.

text 
ip route vrf Customer1 172.16.1.0 255.255.255.0 172.16.1.1 global 
ip route vrf Customer2 192.168.1.200 255.255.255.255 192.168.1.1 global 
ip route 192.168.1.0 255.255.255.0 Vlan10 
ip route 172.16.1.0 255.255.255.0 Vlan20

• The route in Customer1 VRF provides a path back to the Customer2 subnet, 172.16.1.0/24.
• The route in Customer2 VRF provides a path to the FTP server, 192.168.1.200.
• The keyword global tells the router to resolve the next hop using the global routing table, enabling controlled route leaking between the VRF and global table.
• The global routes identify the VLAN interfaces used to reach each customer network.

• B — Single customer login across properties: Customer 360 Identity provides centralized identity services, allowing an organization to recognize a customer across multiple digital properties and applications. This helps UC understand authenticated activity as part of a broader customer identity.

• C — Multi-brand support: Customer 360 Identity can support multiple brands and user experiences. Identity services can remain centralized while correlating a customer’s activity across different corporate brands or channels.

• A: Customer 360 Identity does not automatically populate all data into Customer 360 Data Manager and Customer 360 Audiences. Integration and data configuration are still required.
• D: Tracking anonymous activity and linking it after sign-up may be possible through broader customer-data and tracking implementations, but it is not the primary Customer 360 Identity benefit tested here. Identity focuses mainly on authentication, registration, and cross-property identity correlation.

• A: It allows for branching and merging...

• C: It allows multiple engineers to work against the same code and configuration files and manage differences and conflicts.

• B: Build automation and infrastructure provisioning are handled by CI/CD and automation tools, not by version control alone.
• D: User Stories and backlogs are managed by project-management tools.
• E: Version control stores and tracks code, but it does not itself ensure that developers write effective unit tests.

• Compare each server’s drive specifications and performance data.
• Identify the drive that is faulty, slow, or mismatched.
• Replace it with a drive that matches the required interface, capacity, and performance characteristics.
• Avoid selecting a slower drive, because storage performance can bottleneck the entire server.
• In a redundant array, use a compatible replacement so rebuilding does not create unnecessary performance degradation.

1. Create or verify cost groups

1. Set up the item model group

1. Create the costing version

1. Enter or calculate item costs

1. Activate the standard costs

• Prevent connections to malware command-and-control servers
• Identify infected systems making those DNS requests
• Collect information for incident response

• A: Attackers do not normally use sinkholes to map a company’s domain structure.
• B: Redirecting employees from legitimate sites to attacker-owned sites describes malicious DNS manipulation, not a defensive sinkhole.
• D: Attracting attackers away from real resources is more closely associated with a honeypot or deception system.

• How quickly the vendor must respond to an incident or request
• Target resolution times
• Availability or uptime requirements
• Performance metrics and penalties for not meeting them

• SOW (Statement of Work): Describes the project’s scope, tasks, deliverables, and timeline.
• MOA (Memorandum of Agreement): Documents a formal agreement to cooperate or perform specific activities.
• MOU (Memorandum of Understanding): Records a mutual understanding or intent, often less binding than a contract.

• Economy: Obtaining inputs at the lowest appropriate cost.
• Efficiency: Making the best use of resources, such as staff, money, and equipment.
• Effectiveness: Achieving the intended objectives or outcomes.

• B. Users accessing Salesforce from public Wi-Fi

• C. Users choosing the same password as their Facebook password

• A: 2FA does not protect an already-authenticated, unlocked session if someone accesses an unattended laptop.
• D: Weak password-reset questions are an account-recovery weakness. 2FA primarily strengthens login authentication, not necessarily the security-question reset process.

• Espionage: Stealing information for intelligence or competitive purposes.
• Data exfiltration: Unauthorized removal or transfer of data.
• Nation-state attack: An attack sponsored or conducted by a government.
• Shadow IT: Technology or access methods used outside approved IT processes.

• Leaf switches provide access ports for servers, endpoints, and other devices.
• Spine switches form the fabric’s backbone.
• Every leaf connects to every spine, creating a predictable, high-bandwidth, low-latency path.

• A: Adding both a spine and leaf is unnecessary for simply adding access ports.
• B: Adding a spine does not directly provide endpoint access ports.
• D: A single connection to one spine creates a bottleneck and a single point of failure.

• B. Versioned configuration files — Infrastructure is defined in machine-readable files and tracked in version control, allowing repeatable provisioning and change history.
• D. Docker files — Assuming “Doctor files” is a typo for Dockerfiles, a Dockerfile declaratively defines how to build a container image and is commonly considered infrastructure/configuration as code.

• A. Cloned virtual machine images — These are prebuilt infrastructure artifacts, but cloning an image is not itself a code-based infrastructure definition.
• C. Change management database records — A CMDB records information about infrastructure; it does not define or provision that infrastructure.

kusto 
Event 
| summarize make_set(EventID) by Computer

• summarize groups records.
• by Computer creates one result row per virtual machine.
• make_set(EventID) returns an array containing unique event IDs for that computer.

kusto 
| summarize make_list(EventID) by Computer

• Plenum: Describes a fire-resistant cable jacket rating, not a transmission medium or speed.
• Ethernet: Describes a networking technology; Ethernet can use copper or fiber, so the term alone does not identify the fastest cable type.
• DAC (Direct Attach Copper): Uses copper and is typically intended for short-distance, high-speed connections in data centers.

• A static IP gives the surveillance system a predictable local address, so users can reliably reach it on the LAN.
• However, a static IP does not block internet-based login attempts. If the router exposes the device through port forwarding, attackers could still reach it.
• Port mapping normally exposes an internal service externally, so A is a poor choice as written.
• Subnetting alone also does not block traffic; it would require routing/firewall rules.

1. Select Exchange email as a location.
2. Use the built-in Azure Storage Account key sensitive information type as the condition.
3. Configure the DLP action to encrypt the email—for example, using Microsoft Purview Message Encryption.

• What information each stakeholder needs
• When and how often it should be communicated
• Which format or channel should be used
• Who is responsible for communicating it

• A: The team should not decide stakeholder communications without first checking the established plan and CEO’s needs.
• B: An executive summary may be appropriate, but choosing a solution before reviewing the plan is premature.
• D: The stakeholder engagement plan addresses how to engage stakeholders, but this is primarily a communication planning issue.

• A: Reduce management overhead — This is generally an advantage of public cloud, not hybrid cloud. Hybrid environments can increase management complexity.
• B: Cross-platform virtualization — Not the defining advantage of hybrid cloud.
• D: Leverage IaaS and PaaS — Public clouds commonly provide both IaaS and PaaS, so this is not unique to hybrid cloud.

1. Start with the 48-bit MAC address.
2. Split it into two 24-bit halves.
3. Insert FF:FE between the halves, creating a 64-bit value.
4. Invert the U/L bit—the seventh bit from the left in the first MAC byte.

text 
MAC:       00:1A:2B:3C:4D:5E 
EUI-64:    02:1A:2B:FF:FE:3C:4D:5E

• FE80 is the prefix commonly used for an IPv6 link-local address, not part of the EUI-64 interface ID.
• The interface ID is not random.
• The MAC address is modified by inserting FF:FE and changing the U/L bit.

• Matching hashes: The software is unchanged.
• Different hashes: The software was modified or corrupted.

• Encryption: Protects confidentiality.
• Baselines: Define approved configurations or normal performance.
• Tokenization: Replaces sensitive data with tokens.

• C — Some risks cannot be eliminated.

• D — Accepting residual risk does not imply recklessness.

• E — Most companies in this industry will say something similar.

• The requirement is an assessment of the Azure environment’s design, which requires a support plan offering proactive architectural guidance.
• Premier support would provide this capability, but it is a high-cost option.
• Since the requirement says to minimize expenses, Premier is not the best recommendation.
• A lower-cost plan with the required advisory/design-review capability—historically Professional Direct in Azure’s support-plan model—would be more appropriate.

1. You try to access a cloud application, such as accounting software.
2. The application redirects you to the company’s IdP.
3. You authenticate with the IdP.
4. The IdP sends a digitally signed SAML assertion to the application.
5. The application validates the assertion and grants access.

• The user’s identity
• Whether authentication succeeded
• Roles or group membership
• Access-related attributes

• Conserve public IPv4 addresses: IPv4 addresses are limited, so many internal devices share a smaller number of public addresses through NAT.
• Reduce direct exposure: Private addresses are not directly routable from the public Internet, which helps reduce unsolicited access to internal devices.

• Customer: Dual
• Date: Dual
• Sales: DirectQuery
• SalesAggregate: Import

• Sales – DirectQuery: Near-real-time data should not rely on an imported cache. DirectQuery sends queries to the source when visuals are loaded, allowing recent sales data to appear.
• SalesAggregate – Import: A weekly refresh is sufficient, and imported data generally gives faster visual performance because it is stored in Power BI’s in-memory cache.
• Customer and Date – Dual: These are dimension tables used with both the DirectQuery Sales table and the imported SalesAggregate table. Dual allows Power BI to use cached data when possible, while still behaving appropriately in queries involving DirectQuery data. This can improve performance and reduce unnecessary limited relationships.

• Microservices: An application-design approach that divides an application into smaller services. It does not inherently reduce the number of operating systems.
• Virtualization: Creates virtual machines, but each VM generally requires its own complete operating system. This improves isolation but does not minimize OS instances as effectively.
• Infrastructure as code: Uses code to automate infrastructure deployment and configuration. It improves consistency but does not determine how many operating systems are used.

• Scheduling overlapping working hours for critical collaboration
• Assigning independent tasks that can proceed asynchronously
• Adding clear handoffs between offices
• Documenting decisions, questions, and required inputs
• Building appropriate time into the schedule for responses

• Espionage: Stealing information for intelligence or competitive purposes.
• Data exfiltration: Unauthorized removal or transfer of data.
• Nation-state attack: An attack sponsored or conducted by a government.
• Shadow IT: Unapproved technology or methods used to access organizational resources.

• 2000::/3 — Global unicast, used for publicly routable IPv6 addresses.
• FC00::/7 — Unique local, used for private internal addressing.
• FE80::/10 — Link-local, used only on the local network segment and not routed between subnets.

• A: Person Accounts cannot be merged directly with standard Contact records.
• C: There is no Account Setup option that automatically merges Person Account duplicates.
• D: Matching rules and duplicate rules can help identify or prevent duplicates, but they do not automatically merge Person Accounts. Also, relationship considerations do not change the basic merge capability.

• Determining ISP-assigned address space: Usually involves public reconnaissance, such as WHOIS or regional Internet registry information.
• Bypassing DNS sinkholing: Would require evidence that malicious domains are resolving outside the organization’s sinkhole controls.
• Achieving initial access: DNS log entries alone do not demonstrate compromise or entry.
• Exfiltrating data: DNS tunneling generally involves repeated queries containing encoded or unusually long data, not merely internal host discovery.

• A. Microsoft 365 group with Assigned membership
• C. Microsoft 365 group with Dynamic User membership

Why?

• Assigned membership: You explicitly add User1, User2, and User3.
• Dynamic User membership: Membership is automatically determined by a rule based on user attributes.

Why the other options are incorrect

• B and D: Security groups do not support the Microsoft 365 group expiration policy.
• E: Dynamic Device groups are intended for devices, not these users, and are also security groups.

• Input feature distributions differ from training data ? Analyze dataset drift metrics

• Model accuracy drops without code changes ? Analyze dataset drift metrics

• Endpoint latency increases under load ? Investigate scaling and infrastructure metrics

• User preferences change, so the model must learn from recent data.
• Keeping the existing data helps preserve knowledge of older patterns and provides a broader training distribution.
• Training only on new data can cause catastrophic forgetting and may overfit if the new dataset is small.
• The new data should not automatically be used as the test set, because it is needed for training and the model must still be evaluated on separate, representative data.

• Managerial: policies, standards, risk management, governance
• Operational: procedures carried out by people, such as training, incident response, and backups
• Technical: firewalls, encryption, access-control systems
• Physical: locks, guards, cameras

• An Azure pay-as-you-go subscription follows an operational expenditure (OpEx) model.
• With OpEx, the organization pays for services as they are used, typically based on consumption.
• There is no need to purchase and maintain physical servers upfront.
• This contrasts with capital expenditure (CapEx), where the company makes a significant upfront investment in infrastructure, such as on-premises Hyper-V hosts.

• T?o m?t Systems Manager Automation runbook d? ch?y l?nh kh?i d?ng l?i ?ng d?ng trên các EC2 instance.
• T?o m?t Amazon EventBridge rule ph?n ?ng khi CloudWatch alarm chuy?n sang tr?ng thái ALARM.
• Ð?t Automation runbook làm target c?a EventBridge rule.

1. Log c?a ?ng d?ng du?c ghi vào CloudWatch Logs.
2. CloudWatch alarm phát hi?n nhi?u l?i liên quan d?n vi?c restart.
3. Alarm chuy?n sang tr?ng thái ALARM.
4. EventBridge nh?n s? ki?n thay d?i tr?ng thái này.
5. EventBridge g?i Systems Manager Automation runbook.
6. Runbook restart ?ng d?ng trên các EC2 instance, không restart c? instance.

• A: SNS không tr?c ti?p g?i Systems Manager Automation runbook nhu m?t target native.
• B: Lambda có th? th?c hi?n vi?c restart, nhung ph?i t? x? lý vi?c xác d?nh instance và ch?y l?nh t? xa.
• C: Lambda ch? làm trung gian d? g?i runbook, không c?n thi?t vì EventBridge có th? g?i runbook tr?c ti?p.

1. Which host originated the infection

1. Which remaining hosts are infected

• You can configure different pre-shared keys for different device groups.
• All cameras could use one key.
• All scanners could use another key.
• Each key can be associated with an appropriate role or access policy.

1. Get Data > Folder

1. Expand the Attributes column

1. Remove the Content column

• Folder connector: lists files and their metadata, but also includes a Content binary column.
• Combine Files: processes and combines the actual CSV contents, which is explicitly disallowed here.