Quiz AWS Certified Solutions Architect - Associate (SAA-C01 Korean Version)

Amazon S3
Requests to Amazon S3 can be authenticated or anonymous. Authenticated access requires
credentials that AWS can use to authenticate your requests. When making REST API calls
directly from your code, you create a signature using valid credentials and include the
signature in your request. Amazon Simple Storage Service (Amazon S3) is an object storage
service that offers industry-leading scalability, data availability, security, and performance.
This means customers of all sizes and industries can use it to store and protect any amount
of data for a range of use cases, such as websites, mobile applications, backup and restore,
archive, enterprise applications, IoT devices, and big data analytics. Amazon S3 provides
easy-to-use management features so you can organize your data and configure finely-tuned
access controls to meet your specific business, organizational, and compliance requirements.
Amazon S3 is designed for 99.999999999% (11 9's) of durability, and stores data for millions
of applications for companies all around the world.
https://aws.amazon.com/s3/

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

Scheduled Reserved Instances
Scheduled Reserved Instances (Scheduled Instances) enable you to purchase capacity
reservations that recur on a daily, weekly, or monthly basis, with a specified start time and
duration, for a one-year term. You reserve the capacity in advance, so that you know it is
available when you need it. You pay for the time that the instances are scheduled, even if
you do not use them.
Scheduled Instances are a good choice for workloads that do not run continuously, but do
run on a regular schedule. For example, you can use Scheduled Instances for an application
that runs during business hours or for batch processing that runs at the end of the week.
If you require a capacity reservation on a continuous basis, Reserved Instances might meet
your needs and decrease costs.
How Scheduled Instances Work
Amazon EC2 sets aside pools of EC2 instances in each Availability Zone for use as
Scheduled Instances. Each pool supports a specific combination of instance type, operating
system, and network.
To get started, you must search for an available schedule. You can search across multiple
pools or a single pool. After you locate a suitable schedule, purchase it.
You must launch your Scheduled Instances during their scheduled time periods, using a
launch configuration that matches the following attributes of the schedule that you purchased:
instance type, Availability Zone, network, and platform. When you do so, Amazon EC2
launches EC2 instances on your behalf, based on the specified launch specification. Amazon
EC2 must ensure that the EC2 instances have terminated by the end of the current
scheduled time period so that the capacity is available for any other Scheduled Instances it is
reserved for. Therefore, Amazon EC2 terminates the EC2 instances three minutes before the
end of the current scheduled time period.
You can't stop or reboot Scheduled Instances, but you can terminate them manually as
needed. If you terminate a Scheduled Instance before its current scheduled time period ends,
you can launch it again after a few minutes. Otherwise, you must wait until the next
scheduled time period.
The following diagram illustrates the lifecycle of a Scheduled Instance.

Tap the image to zoom
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-scheduled-instances.html

Https://aws.amazon.com/cloudhsm/

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

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

Migrating Existing Files to Amazon FSx for Windows File Server Using AWS DataSync We
recommend using AWS DataSync to transfer data between Amazon FSx for Windows File
Server file systems. DataSync is a data transfer service that simplifies, automates, and
accelerates moving and replicating data between on-premises storage systems and other
AWS storage services over the internet or AWS Direct Connect. DataSync can transfer your
file system data and metadata, such as ownership, time stamps, and access permissions.
Reference: https://docs.aws.amazon.com/fsx/latest/WindowsGuide/migrate-files-to-fsx-
datasync.html