ACP-Cloud1 Dumps Questions With Valid Answers

C. OSS

Explanation: OSS (Object Storage Service) is a secure, cost-effective, and highly reliable cloud storage service that allows you to store, back up, and archive any amount of data in the cloud1. OSS is ideal for storing logs, as it provides 99.9999999999% (12 nines) durability and 99.995% availability or service continuity1. OSS also supports lifecycle management, which allows you to automatically delete or transition objects to lower-cost storage classes based on your predefined rules2. OSS offers four tiers of storage: Standard, Infrequent Access, Archive, and Cold Archive. Each tier is cost-optimized for specific storage patterns1. The Archive and Cold Archive tiers are suitable for storing infrequently accessed data, such as logs, for a long time. The Archive tier offers data retrieval time within one minute, while the Cold Archive tier offers expedited data retrieval time within an hour1. Therefore, OSS can help the website extend the log retention period to 24 months and ensure that logs can be quickly downloaded when needed.
CDN (Content Delivery Network) is a distributed network that delivers content to users based on their geographic locations, the origin sites, and the content delivery nodes3. CDN is mainly used for content distribution, such as static web pages, images, videos, and downloads3. CDN is not suitable for storing logs, as it does not provide data durability or lifecycle management.
Container Service is a high-performance and scalable container application management service that enables you to use Docker and Kubernetes to manage the lifecycle of containerized applications4. Container Service is mainly used for deploying and orchestrating microservices, serverless applications, and big data applications4. Container Service is not suitable for storing logs, as it does not provide data durability or lifecycle management.
ApsaraDB for RDS (Relational Database Service) is a stable and reliable online database service that supports MySQL, SQL Server, PostgreSQL, MariaDB, and PPAS5. ApsaraDB for RDS is mainly used for storing and processing structured data, such as user information, transaction records, and product catalogs5. ApsaraDB for RDS is not suitable for storing logs, as it is more expensive and less scalable than OSS. References: Object Storage Service (OSS) - Alibaba Cloud, Lifecycle management - Object Storage Service - Alibaba Cloud Documentation Center, Content Delivery Network (CDN) - Alibaba Cloud, Container Service - Alibaba Cloud, ApsaraDB for RDS - Alibaba Cloud

D. PPPoE

Explanation: PPPoE stands for Point-to-Point Protocol over Ethernet, which is a network protocol that encapsulates PPP frames in Ethernet frames and allows multiple computers to share a single Internet connection. PPPoE is typically used by Internet service providers (ISPs) to provide broadband access to their customers, such as DSL or cable modem. PPPoE is not a protocol that is commonly supported by Open API for cloud computing service providers, because it is not designed for web-based communication and requires a dedicated connection between the client and the server. Open API, on the other hand, is a term that refers to a set of publicly available application programming interfaces (APIs) that allow developers to access the functionality and data of cloud computing service providers. Open API usually follows standard protocols that are widely used on the web, such as HTTP, Restful, and Web Service. HTTP stands for Hypertext Transfer Protocol, which is the foundation of data communication on the web. HTTP defines how messages are formatted and transmitted, and what actions web servers and browsers should take in response to various commands. HTTP is a stateless protocol, which means that each request is independent and does not depend on any previous requests or responses. Restful stands for Representational State Transfer, which is an architectural style for designing web services that are based on the concept of resources. Restful web services use HTTP methods (such as GET, POST, PUT, and DELETE) to perform operations on resources, and use standard formats (such as JSON or XML) to exchange data. Restful web services are stateless, scalable, and cacheable, and aim to provide a uniform interface for interacting with different types of resources. Web Service is a generic term that refers to any software service that is available over the web and uses a standardized format for communication, such as SOAP or REST. Web Service allows different applications to communicate and exchange data across different platforms and languages. Web Service can be described using a specification language, such as WSDL or OpenAPI, which defines the structure, operations, and parameters of the service. Web Service can also be registered and discovered using a directory service, such as UDDI or Swagger.

D. Security Center

Explanation: Security Center is a centralized security management system that dynamically identifies and analyzes security threats, and generates alerts when threats are detected. Security Center provides multiple features to ensure the security of cloud resources and servers in data centers1. Security Center can help the company to quickly resolve its security problems by providing the following benefits:
Unified security management: Security Center automatically collects various log data from the company’s services on the cloud, and implements control over found security threats. Security Center can also manage assets, attacks, vulnerabilities, and threats in the Security Center console2.
Proactive defense: Security Center supports the proactive detection and termination of mainstream ransomware, mining programs, backdoor programs, worms, malicious programs, DDoS trojans, and trojan programs. Security Center also prevents websites from being maliciously implanted with the acts that involve terrorism, politics, dark chains, trojans, and backdoors. This ensures the normal operation of web page information2.
Automated security operations: Security Center automatically traces the sources and causes of attacks. This helps the company understand the ins and outs of intrusion threats and make quick responses. Security Center also supports custom alerts and third-party data migration to the cloud in a secure manner2.

D. X-Forwarded-For

Explanation: The X-Forwarded-For field in HTTP header is used to identify the originating IP address of a client connecting to a web server through an HTTP proxy or a load balancer. When the “Obtain the Visitor’s Real IP Address” function is enabled in Alibaba Cloud SLB, the SLB instance adds the X-Forwarded-For field to the HTTP header of each request and forwards the request to the backend server. The backend server can then obtain the real IP address of the visitor from the X-Forwarded-For field1. The format of the X-Forwarded-For field is as follows:
X-Forwarded-For: client, proxy1, proxy2
where the value is a comma+space separated list of IP addresses, the left-most being the original client, and each successive proxy that passed the request adding the IP address where it received the request from. In this example, the request passed through proxy1, proxy2, and then the SLB instance (proxy3).2 References: Obtain client IP addresses - Server Load Balancer - Alibaba Cloud, XForwarded- For - MDN Web Docs

Explanation: Pay-As-You-Go is a billing method that allows you to pay for resources after you use them. You are billed based on the actual usage of resources, such as the number of hours that an ECS instance runs or the amount of data that is transferred. Pay-As-You- Go is suitable for scenarios where the demand for resources is unpredictable, flexible, or short-term1. Pay-As-You-Go has the following advantages for the startup video streaming company:
No upfront payment: The company does not need to pay any fees in advance when they purchase ECS instances. They only pay for the resources that they actually use, which can help them save costs and optimize their cash flow1.
Flexible scaling: The company can easily scale up or down their ECS instances based on the actual demand for their service. They can add more ECS instances during peak hours or events, such as Christmas, and release them when the demand drops. They can also change the configurations of their ECS instances at any time, such as upgrading the CPU, memory, or bandwidth1.
No long-term commitment: The company does not need to commit to a long-term contract or subscription when they use Pay-As-You-Go. They can release their ECS instances at any time without incurring any penalties or fees. They can also switch to other billing methods, such as Subscription or Savings Plan, if their business needs change1.
The other billing methods of ECS are not as suitable as Pay-As-You-Go for the company’s scenario, for the following reasons:
Pay-As-You-Go with Reserved Instances: Reserved Instances are a type of discount coupon that can be used to deduct a portion of the fees incurred by Pay- As-You-Go instances that match the attributes of the Reserved Instances, such as region, zone, instance type, and operating system2. Reserved Instances require upfront payment and have a fixed term of one year or three years. They are suitable for scenarios where the demand for resources is stable and predictable, and where the user wants to enjoy lower prices than Pay-As-You-Go2. However, for the company’s scenario, Reserved Instances are not a good option, because they do not need to purchase a large number of ECS instances for a long period of time, and they want to have more flexibility and scalability in their resource management.
Subscription with Reserved Instances: Subscription is a billing method that allows you to pay for resources in advance for a specific period of time, such as one month, one year, or three years. You are billed based on the specifications and duration of the resources that you purchase, regardless of whether you use them or not. Subscription is suitable for scenarios where the demand for resources is stable and long-term, and where the user wants to enjoy lower prices than Pay-As- You-Go3. Subscription with Reserved Instances can further reduce the cost of Subscription instances by applying the Reserved Instances discounts to them2. However, for the company’s scenario, Subscription with Reserved Instances are not a good option, because they do not want to pay for resources in advance or commit to a long-term contract, and they want to have more flexibility and scalability in their resource management.
Pay-As-You-Go with Savings Plan: Savings Plan is a billing method that allows you to commit to a consistent amount of usage (measured in USD/hour) for a one year or three-year term, and in exchange, receive a lower price for that usage4. Savings Plan can be applied to any Pay-As-You-Go instances that match the attributes of the Savings Plan, such as region, instance family, or operating system4. Savings Plan is suitable for scenarios where the demand for resources is stable and predictable, and where the user wants to enjoy lower prices than Pay- As-You-Go and more flexibility than Subscription4. However, for the company’s scenario, Savings Plan is not a good option, because they do not want to commit to a consistent amount of usage for a long period of time, and they want to have more flexibility and scalability in their resource management.