Quiz AWS Certified Solutions Architect - Associate (SAA-C01日本語版)

What Is Amazon CloudFront?
Amazon CloudFront is a web service that speeds up distribution of your static and dynamic
web content, such as .html, .css, .js, and image files, to your users. CloudFront delivers your
content through a worldwide network of data centers called edge locations. When a user
requests content that you're serving with CloudFront, the user is routed to the edge location
that provides the lowest latency (time delay), so that content is delivered with the best
possible performance.
Using Amazon S3 Buckets for Your Origin
When you use Amazon S3 as an origin for your distribution, you place any objects that you
want CloudFront to deliver in an Amazon S3 bucket. You can use any method that is
supported by Amazon S3 to get your objects into Amazon S3, for example, the Amazon S3
console or API, or a third-party tool. You can create a hierarchy in your bucket to store the
objects, just as you would with any other Amazon S3 bucket.
Using an existing Amazon S3 bucket as your CloudFront origin server doesn't change the
bucket in any way; you can still use it as you normally would to store and access Amazon S3
objects at the standard Amazon S3 price. You incur regular Amazon S3 charges for storing
the objects in the bucket.
https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/Introduction.html
https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/DownloadDistS3An
dCustomOrigins.h

Data can be recover if versioning enable, also it provide a extra protection like file
delete,MFA delete. MFA Delete only works for CLI or API interaction, not in the AWS
Management Console. Also, you cannot make version DELETE actions with MFA using IAM
user credentials. You must use your root AWS account.
https://aws.amazon.com/blogs/security/securing-access-to-aws-using-mfa-part-3/ Object
Versioning Use Amazon S3 Versioning to keep multiple versions of an object in one bucket.
For example, you could store my-image.jpg (version 111111) and my-image.jpg (version
222222) in a single bucket. S3 Versioning protects you from the consequences of unintended
overwrites and deletions. You can also use it to archive objects so that you have access to
previous versions.
You must explicitly enable S3 Versioning on your bucket. By default, S3 Versioning is
disabled. Regardless of whether you have enabled Versioning, each object in your bucket
has a version ID. If you have not enabled Versioning, Amazon S3 sets the value of the
version ID to null. If S3 Versioning is enabled, Amazon S3 assigns a version ID value for the
object. This value distinguishes it from other versions of the same key.
https://docs.aws.amazon.com/AmazonS3/latest/dev/ObjectVersioning.html

Amazon Simple Queue Service
Amazon Simple Queue Service (SQS) is a fully managed message queuing service that
enables you to decouple and scale microservices, distributed systems, and serverless
applications. SQS eliminates the complexity and overhead associated with managing and
operating message oriented middleware, and empowers developers to focus on
differentiating work. Using SQS, you can send, store, and receive messages between
software components at any volume, without losing messages or requiring other services to
be available. Get started with SQS in minutes using the AWS console, Command Line
Interface or SDK of your choice, and three simple commands.
SQS offers two types of message queues. Standard queues offer maximum throughput, best-
effort ordering, and at-least-once delivery. SQS FIFO queues are designed to guarantee that
messages are processed exactly once, in the exact order that they are sent.
Scaling Based on Amazon SQS
There are some scenarios where you might think about scaling in response to activity in an
Amazon SQS queue. For example, suppose that you have a web app that lets users upload
images and use them online. In this scenario, each image requires resizing and encoding
before it can be published. The app runs on EC2 instances in an Auto Scaling group, and it's
configured to handle your typical upload rates. Unhealthy instances are terminated and
replaced to maintain current instance levels at all times. The app places the raw bitmap data
of the images in an SQS queue for processing. It processes the images and then publishes
the processed images where they can be viewed by users. The architecture for this scenario
works well if the number of image uploads doesn't vary over time. But if the number of
uploads changes over time, you might consider using dynamic scaling to scale the capacity
of your Auto Scaling group.
https://aws.amazon.com/sqs/#:~:text=Amazon%20SQS%20leverages%20the%20AWS,queu
es%20provide%20n
https://docs.aws.amazon.com/autoscaling/ec2/userguide/as-using-sqs-queue.html

Amazon RDS Read Replicas Now Support Multi-AZ Deployments
Starting today, Amazon RDS Read Replicas for MySQL and MariaDB now support Multi-AZ
deployments.
Combining Read Replicas with Multi-AZ enables you to build a resilient disaster recovery
strategy and simplify your database engine upgrade process.
Amazon RDS Read Replicas enable you to create one or more read-only copies of your
database instance within the same AWS Region or in a different AWS Region. Updates
made to the source database are then asynchronously copied to your Read Replicas. In
addition to providing scalability for read-heavy workloads, Read Replicas can be promoted to
become a standalone database instance when needed.
Amazon RDS Multi-AZ deployments provide enhanced availability for database instances
within a single AWS Region. With Multi-AZ, your data is synchronously replicated to a
standby in a different Availability Zone (AZ). In the event of an infrastructure failure, Amazon
RDS performs an automatic failover to the standby, minimizing disruption to your
applications.
You can now use Read Replicas with Multi-AZ as part of a disaster recovery (DR) strategy
for your production databases. A well-designed and tested DR plan is critical for maintaining
business continuity after a disaster. A Read Replica in a different region than the source
database can be used as a standby database and promoted to become the new production
database in case of a regional disruption.
You can also combine Read Replicas with Multi-AZ for your database engine upgrade
process. You can create a Read Replica of your production database instance and upgrade it
to a new database engine version. When the upgrade is complete, you can stop applications,
promote the Read Replica to a standalone database instance, and switch over your
applications. Since the database instance is already a Multi-AZ deployment, no additional
steps are needed.
Overview of Amazon RDS Read Replicas
Deploying one or more read replicas for a given source DB instance might make sense in a
variety of scenarios, including the following:
Scaling beyond the compute or I/O capacity of a single DB instance for read-heavy database
workloads. You can direct this excess read traffic to one or more read replicas.
Serving read traffic while the source DB instance is unavailable. In some cases, your source
DB instance might not be able to take I/O requests, for example due to I/O suspension for
backups or scheduled maintenance. In these cases, you can direct read traffic to your read
replicas. For this use case, keep in mind that the data on the read replica might be "stale"
because the source DB instance is unavailable.
Business reporting or data warehousing scenarios where you might want business reporting
queries to run against a read replica, rather than your primary, production DB instance.
Implementing disaster recovery. You can promote a read replica to a standalone instance as
a disaster recovery solution if the source DB instance fails.
https://aws.amazon.com/about-aws/whats-new/2018/01/amazon-rds-read-replicas-now-
support-multi-az-deploym
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_ReadRepl.html