Chapter 1: Introduction to AWS

Chapter 1: Introduction to AWS

1. D. A region is a named set of AWS resources in the same geographical area. A region comprises at least two Availability Zones. Endpoint, Collection, and Fleet do not describe a physical location around the world where AWS clusters data centers.

• region是描述基于地理位置的AWS数据中心资源，同时一个region由至少两个AZ组成。

2. A. An Availability Zone is a distinct location within a region that is insulated from failures in other Availability Zones and provides inexpensive, low-latency network connectivity to other Availability Zones in the same region. Replication areas, geographic districts, and compute centers are not terms used to describe AWS data center locations.

• 一个region有两个以上的AZ组成。通过区域内的AZ完成高可用、容错的处理。

3. B. A hybrid deployment is a way to connect infrastructure and applications between cloud-based resources and existing resources that are not located in the cloud. An all-in deployment refers to an environment that exclusively runs in the cloud. An on-premises deployment refers to an environment that runs exclusively in an organization’s data center.

• 混合部署就是将公有云和私有云打通的部署方式；

4. C. Amazon CloudWatch is a monitoring service for AWS Cloud resources and the applications organizations run on AWS. It allows organizations to collect and track metrics, collect and monitor log files, and set alarms. AWS IAM, Amazon SNS, and AWS CloudFormation do not provide visibility into resource utilization, application performance, and the operational health of your AWS resources.

• CloudWatch被用作进行AWS的云服务资源的监控；

5. B. Amazon DynamoDB is a fully managed, fast, and flexible NoSQL database service for all applications that need consistent, single-digit millisecond latency at any scale. Amazon SQS, Amazon ElastiCache, and Amazon RDS do not provide a NoSQL database service. Amazon SQS is a managed message queuing service. Amazon ElastiCache is a service that provides in-memory cache in the cloud. Finally, Amazon RDS provides managed relational databases.

• 只有DynamoDB是nosqldb
• Elasticache只是提供了cache能力，支持memcached和redis

6. A. Auto Scaling helps maintain application availability and allows organizations to scale
   Amazon Elastic Compute Cloud (Amazon EC2) capacity up or down automatically according to conditions defined for the particular workload. Not only can it be used to help ensure that the desired number of Amazon EC2 instances are running, but it also allows resources to scale in and out to match the demands of dynamic workloads. Amazon Glacier, Amazon SNS, and Amazon VPC do not provide services to scale compute capacity automatically.

• Auto Scaling支持抢购性质的峰值应用场景；

7. D. Amazon CloudFront is a web service that provides a CDN to speed up distribution of your static and dynamic web content—for example, .html, .css, .php, image, and media files—to end users. Amazon CloudFront delivers content through a worldwide network of edge locations. Amazon EC2, Amazon Route 53, and AWS Storage Gateway do not provide CDN services that are required to meet the needs for the photo sharing service.

• CloudFront 提供了类似CDN的功能，支持在全世界进行分布式cache数据的能力。

8. A. Amazon EBS provides persistent block-level storage volumes for use with Amazon EC2 instances on the AWS Cloud. Amazon DynamoDB, Amazon Glacier, and AWS CloudFormation do not provide persistent block-level storage for Amazon EC2 instances. Amazon DynamoDB provides managed NoSQL databases. Amazon Glacier provides lowcost archival storage. AWS CloudFormation gives developers and systems administrators an easy way to create and manage a collection of related AWS resources.

• ec2本身的存储不支持关机后的持久化，EBS支持关机后的持久化

9. C. Amazon VPC lets organizations provision a logically isolated section of the AWS Cloud where they can launch AWS resources in a virtual network that they define. Amazon SWF, Amazon Route 53, and AWS CloudFormation do not provide a virtual network.Amazon SWF helps developers build, run, and scale background jobs that have parallel or sequential steps. Amazon Route 53 provides a highly available and scalable cloud Domain Name System (DNS) web service. Amazon CloudFormation gives developers and systems administrators an easy way to create and manage a collection of related AWS resources.

• VPC提供了虚拟访问的网络。

10. B. Amazon SQS is a fast, reliable, scalable, fully managed message queuing service that allows organizations to decouple the components of a cloud application. With Amazon
    SQS, organizations can transmit any volume of data, at any level of throughput, without losing messages or requiring other services to be always available. AWS CloudTrail records AWS API calls, and Amazon Redshift is a data warehouse, neither of which
    would be useful as an architecture component for decoupling components. Amazon SNS provides a messaging bus complement to Amazon SQS; however, it doesn’t provide the decoupling of components necessary for this scenario.

• 这类投票类业务的高并发要求较高，只有通过SQS才能完成写入解耦
• CloudTrail 是记录AWS api调用的。
• Redshift是一个数据仓库
• SNS提供消息订阅发布能力，可以通过SQS/lamda/https 等方式订阅消息

知识点总结

• Understand the global infrastructure. AWS provides a highly available technology infrastructure platform with multiple locations worldwide. These locations are composed of regions and Availability Zones. Each region is located in a separate geographic area and has multiple, isolated locations known as Availability Zones.

• 理解AWS的全球架构，AWS在全球多个区域提供了高可用的基础设施架构。这些位置由Region和AZ组成。每个Region在不同的地理区域，拥有多个AZ

• Understand regions. An AWS region is a physical geographic location that consists of a cluster of data centers. AWS regions enable the placement of resources and data in multiple locations around the globe. Each region is completely independent and is designed to be completely isolated from the other regions. This achieves the greatest possible fault tolerance and stability. Resources aren’t replicated across regions unless organizations choose to do so.

• 理解Regions。AWS的region是一个物理位置上隔离的区域，由多个数据中心集群组成。这个成就可以最大程度的提升容灾与稳定性；资源不会被跨region复制，除非企业组织选择这么做；

• Understand Availability Zones. An Availability Zone is one or more data centers within a region that are designed to be isolated from failures in other Availability Zones. Availability Zones provide inexpensive, low-latency network connectivity to other zones in the same region. By placing resources in separate Availability Zones, organizations can protect their
  website or application from a service disruption impacting a single location.

• 理解下AZ。一个AZ是在一个region中，由一个或者多个互相隔离的数据中心组成。AZ提供基于同一个region的低成本、低延迟网络。通过将不同的资源放到不同的AZ中，组织可以保护他们的网站或者应用不受单点故障影响；

• Understand the hybrid deployment model. A hybrid deployment model is an architectural pattern providing connectivity for infrastructure and applications between cloud-based resources and existing resources that are not located in the cloud.

• 理解混合部署模型。一个混合部署架构就是提供云端及非云端的连接；