AWS Certified Solutions Architect Associate (SAA02) – Free Practice Tests

Explanation

If an EBS volume is attached to a running EC2 instance, the user needs to detach the volume from the original instance and then attach it to a new running instance. The user doesn’t need to stop or terminate the original instance.

Explanation

You can use geo restriction, also known as geoblocking, to prevent users in specific geographic locations from accessing content that you’re distributing through a CloudFront web distribution.

To use geo restriction, you have two options:

Explanation

If you stop the instances you will not be charged and the data will still be kept. If you terminate the instances you will lose all your data. If you take a snapshot of all the instances and then terminate all the instances you will not be charged but will still have all your data in the snapshot which can be restored later.

Explanation

The pricing of SQS is as follows: You pay only for what you use, and there is no minimum fee. The cost of Amazon SQS is calculated per request, plus data transfer charges for data transferred out of Amazon SQS. The Amazon SQS Free Tier provides you with 1 million requests per month at no charge. Many small-scale applications are able to operate entirely within the limits of the Free Tier. However, data transfer charges might still apply.

Explanation

Check the network access control list (ACL) for the subnet. The network ACLs must allow inbound and outbound traffic from your local IP address on the proper port. The default network ACL allows all inbound and outbound traffic. To enable Internet access for the EC2 instances in a VPC, you must create an Internet Gateway as well as a route to it in the router table.

Explanation

Versioning provides redundancy as it keeps multiple variants of an object in the same bucket. You can use versioning to preserve, retrieve, and restore every version of every object stored in your Amazon S3 bucket. With versioning, you can easily recover from both unintended user actions and application failures.

Explanation

Persistent storage—If you need persistent virtual disk storage similar to a physical disk drive for files or other data that must persist longer than the lifetime of a single Amazon EC2 instance, Amazon EBS volumes or Amazon S3 are more appropriate. There is also the cost of data uploads as well as frequent transfers and downloads. While Glacier would be an effective archival service, the data may be accessed frequently, which would get expensive quickly for this start up.

Explanation

On-premises data centers have costs associated with the servers, storage, networking, power, cooling, physical space, and IT labor required to support applications and services running in the production environment. For servers, these questions are most applicable: What is your average server utilization? How much do you overprovision for peak load? What is the cost of over-provisioning?

Explanation

Backup and restore, as defined in the “Using Amazon Web Services for Disaster Recovery” white paper, is most like traditional off-site backup replication. You can leverage services such as Amazon S3 or Amazon Storage Gateway to provide a backup replication target and Amazon EC2 can be used to restore access to your applications. This strategy for disaster recovery is the slowest of all AWS DR strategies.

Explanation

When you create a snapshot of a Throughput Optimized HDD (st1) or Cold HDD (sc1) volume, performance may drop as far as the volume’s baseline value while the snapshot is in progress. This behavior is specific to these volume types.

Explanation

You can place a network interface on each of your web servers that connects to a mid-tier network where an application server resides. The application server can also be dual-homed to a back-end network (subnet) where the database server resides. Instead of routing network packets through the dual-homed instances, each dual-homed instance receives and processes requests on the front end, initiates a connection to the back end, and then sends requests to the servers on the back-end network.

Explanation

Amazon CloudWatch Alarms have three possible states: OK: The metric is within the defined threshold ALARM: The metric is outside of the defined threshold INSUFFICIENT_DATA: The alarm has just started, the metric is not available, or not enough data is available for the metric to determine the alarm state

Explanation

Blue/green deployments resolve application unavailability during updates.

Explanation

Amazon S3 supports several mechanisms that give you flexibility to control who can access your data as well as how, when, and where they can access it. Amazon S3 provides four different access control mechanisms: AWS Identity and Access Management (IAM) policies, Access Control Lists (ACLs), bucket policies, and query string authentication. IAM enables organizationsto create and manage multiple users under a single AWS account. With IAM policies, you can grant IAM users fine-grained control to your Amazon S3 bucket or objects. You can use ACLs to selectively add (grant) certain permissions on individual objects. Amazon S3 bucket policies can be used to add or deny permissions across some or all of the objects within a single bucket. With Query string authentication, you have the ability to share Amazon S3 objects through URLs that are valid for a specified period of time.

Explanation

With IAM, you can centrally manage users, security credentials such as access keys, and permissions that control which AWS resources users can access. In some cases, you might have an IAM user with full access to IAM and Amazon S3. If the IAM user assigns a bucket policy to an Amazon S3 bucket and doesn’t specify the root user as a principal, the root user is denied access to that bucket. However, as the root user, you can still access the bucket by modifying the bucket policy to allow root user access.

Explanation

Amazon S3 storage offers very high durability, but it is still a best practice to protect against user level deletion or overwriting of data using versioning, cross-region replication, and MFA Delete.

Explanation

To delete the parts of a failed multipart upload so that you do not get charged for storage of those parts, you must use the command “Abort Multipart Upload” and provide the upload ID of upload you wish to abort. After aborting a multipart upload, you cannot upload any part using that upload ID again. All storage that any parts from the aborted multipart upload consumed is then freed.

Explanation

If an IAM user wants to launch an EC2 instance, you need to grant the EC2 RunInstance permission to that user. If the EC2 instance should include an instance profile—that is, if applications in the EC2 instance will be able to get temporary security credentials via an IAM role—the user who launches the EC2 instance must also have the IAM PassRole permission. Not only that, but the user might need PassRole permission to associate a specific role with the EC2 instance.

Explanation

Amazon SNS and CloudWatch are integrated so you can collect, view, and analyze metrics for every active Amazon SNS notification. By configuring CloudWatch for Amazon SNS, you can gain better insight into the performance of your Amazon SNS topics, push notifications, and SMS deliveries.

Explanation

Using IAM, you apply permissions to IAM users, groups, and roles by creating policies. You can create two types of IAM policies: Managed Policies and Inline Policies. Managed policies are standalone policies that you can attach to multiple users, groups, and roles in your AWS account. Managed policies apply only to identities (users, groups, and roles) – not resources. Inline policies are policies that you create and manage, and that are embedded directly into a single user, group, or role.

Explanation

AWS Identity and Access Management is a web service that allows organizations to manage users and user permissions for various AWS services. The user can add conditions as a part of the IAM policies. The condition can be set on AWS Tags, Time, and Client IP as well as on various parameters. If the organization wants the user to access only specific instances, he should define proper tags and add to the IAM policy condition. The sample policy is shown below.
 "Statement": [
{
"Action": "ec2:*",
"Effect": "Allow",
"Resource": "*",
"Condition": {
"StringEquals": {
"ec2:ResourceTag/InstanceType": "Production"
}
}
}
]

Explanation

An Amazon Machine Image (AMI) is a template that contains a software configuration (for example, an operating system, an application server, and applications). The AMI includes the operating system, initial state of any patches, and any application software. For example, you can select an AMI that has SQL Server. The virtual CPUs are not part of the AMI but are defined by the instance type.

Explanation

A placement group is a logical grouping of instances within a single Availability Zone. Placement groups are recommended for applications that benefit from low network latency, high network throughput, or both. To provide the lowest latency, and the highest packet-per-second network performance for your placement group, choose an instance type that supports enhanced networking

Explanation

AWS is responsible for the security of the cloud in general, in areas such data security and protection against IP spoofing. The customer is responsible for security in the cloud in areas such as data encryption, installing security patches on EC2 instances, and IAM best practices. It is very important to understand this concept to avoid any lapses in your security measures.

Explanation

Most of these choices improve the responsiveness of CloudWatch in some way, but the aspect of this question is improving the responsiveness of CloudWatch alarms you have already implemented. This means you are not interested in additional metric information outside of the custom metrics you’ve already created in CloudWatch, and any features that increase responsiveness to metrics other than what you want will not be beneficial.

So, creating CloudWatch Log metric filters for default RDS metrics will not help, even though this can provide 1-second granularity, it is unlikely the logs will indicate overall latency and throughput of reads and writes, as these performance metrics are not related to specific API calls, but rather general database performance.

Performance Insights allow you to review and analyze your RDS database performance overall, but is not ideal for identifying a performance issue in real-time.

Enabling Enhanced monitoring does provide increased insight into RDS database performance, and with the increased granularity of 5 seconds instead of 60 seconds, or potentially even 1-second granularity through CloudWatch Log Streams. However, Enhanced Monitoring provides specific operating system metrics and other performance metrics, and would not apply to the custom metric you have created using CloudWatch.

Enabling Detailed Monitoring will increase the delivery of average metrics from every 5 minutes to every minute, and this will apply to your custom metrics as well.

In addition, creating a Route 53 CloudWatch Alarm Health Check will monitor the transmission of data to CloudWatch, and can effectively alert you before the CloudWatch alarm is even triggered.

Explanation

You can create a VPC with an instance tenancy of dedicated to ensure that all instances launched into the VPC are dedicated instances. Alternatively, you can specify the tenancy of the instance during launch

Explanation

You can choose between three EBS volume types to best meet the needs of their workloads: General Purpose (SSD), Provisioned IOPS (SSD), and Magnetic. General Purpose (SSD) is the new, SSD-backed, general purpose EBS volume type that we recommend as the default choice for customers. General Purpose (SSD) volumes are suitable for a broad range of workloads, including small to medium sized databases, development and test environments, and boot volumes. Provisioned IOPS (SSD) volumes offer storage with consistent and low-latency performance, and are designed for I/O intensive applications such as large relational or NoSQL databases. Magnetic volumes provide the lowest cost per gigabyte of all EBS volume types. Magnetic volumes are ideal for workloads where data is accessed infrequently, and applications where the lowest storage cost is important

Explanation

You can write an AWS CloudFormation template (a JSON-formatted document) in a text editor or pick an existing template. The template describes the resources you want and their settings. For example, suppose you want to create an Amazon EC2. Your template can declare an instance Amazon EC2 and describe its properties

Explanation

Amazon RDS provides three storage types: magnetic, General Purpose (SSD), and Provisioned IOPS (input/output operations per second). They differ in performance characteristics and price, allowing you to tailor your storage performance and cost to the needs of your database workload. General purpose is good for small to medium sized databases and has the burst to handle spikes.

Explanation

When you create a default VPC, the following components are created with it:

Explanation

Each Amazon S3 bucket and object has an ACL (Access Control List) associated with it. An ACL is a list of grants identifying the grantee and the permission granted. The user can use ACLs to grant basic read/write permissions to other AWS accounts. ACLs use an Amazon S3–specific XML schema. The user cannot grant permissions to other users in his account. ACLs are suitable for specific scenarios. For example, if a bucket owner allows other AWS accounts to upload objects, permissions to these objects can only be managed using the object ACL by the AWS account that owns the object

Explanation

Auto Scaling uses EC2 status checks to detect hardware and software issues with the instances, but the load balancer performs health checks by sending a request to the instance and then waiting for a 200 response code, or by establishing a TCP connection (for a TCP-based health check) with the instance. Even if you’ve configured an Elastic Load Balancer, the autoscaler does not automatically check the ELBs health checks. You must add the ELB Health Check to your autoscaling policy.

Explanation

Many instances can poll a single queue, but to keep multiple instances from processing the same SQS message, your application must delete the SQS message after processing it. While SQS does not guarantee a message will be processed only once, the same message being processed many times is probably an indication that the message is not being deleted following processing.

Explanation

yourwebsite.com is a zone apex. Alias record sets can be used to set a zone apex, but CNAME records cannot. Additionally, queries to Alias records that are mapped to an ELB are free. A records are used to map IPv4 addresses to FQDNs, the IP address of the ELB may change. MX records are used for email servers.

Explanation

In the event of a disaster to your AWS infrastructure you should be able to quickly launch resources in Amazon Web Services (AWS) to ensure business continuity. The following are some key steps you should have in place for preparation: 1. Set up Amazon EC2 instances to replicate or mirror data. 2. Ensure that you have all supporting custom software packages available in AWS. 3. Create and maintain AMIs of key servers where fast recovery is required. 4. Regularly run these servers, test them, and apply any software updates and configuration changes. 5. Consider automating the provisioning of AWS resources.

Explanation

There are some issues that could cause EC2 instances in a VPC to be unable to reach the Internet, including the following. An Internet Gateway must be attached to the VPC for a public subnet. Ingress and egress for Security Groups and Access Control Lists must be correct. EC2 instances in a private subnet need a NAT instance or a NAT Gateway, and for a NAT instance’s source/destination checks must be turned off. EC2 instances in a public subnet must have a route to the Internet Gateway in the route table

Explanation

By default, when you purchase a Reserved Instance, it is executed immediately. Alternatively, you can queue your purchases for a future date and time. For example, you can queue a purchase for around the time that an existing Reserved Instance expires. This can help you ensure that you have uninterrupted coverage.

You can queue purchases for regional Reserved Instances, but not zonal Reserved Instances or Reserved Instances from other sellers. You can queue a purchase up to three years in advance. On the scheduled date and time, the purchase is executed using the default payment method. After the payment is successful, the billing benefit is applied.

Explanation

Amazon S3 is storage for the Internet. It’s a simple storage service that offers software developers a highly-scalable, reliable, and low-latency data storage infrastructure at very low costs. AWS charges less where their costs are less. For example, their costs are lower in the US Standard Region than in the US West (Northern California) Region.

Explanation

Elastic Load Balancing supports both Internet Protocol version 6 (IPv6) and Internet Protocol version 4 (IPv4). Clients can connect to the user’s load balancer using either IPv4 or IPv6 (in EC2-Classic) DNS. However, communication between the load balancer and its back-end instances uses only IPv4. The user can use the Dualstack-prefixed DNS name to enable IPv6 supportfor communications between the client and the load balancers. Thus, the clients are able to access the load balancer using either IPv4 or IPv6 as their individual connectivity needs dictate.

Explanation

In AWS, ephemeral storage is only temporary storage. If the instance is stopped and started back all the data on ephemeral storage will be lost.

Explanation

Amazon EC2 supports the following storage options: Amazon Elastic Block Store (Amazon EBS) Amazon EC2 Instance Store Amazon Simple Storage Service (Amazon S3) Reference:

Explanation

With AWS CloudTrail, you can get a history of AWS API calls for your account, including API calls made via the AWS Management Console, the AWS SDKs, the command line tools, and higher-level AWS services. You can also identify which users and accounts called AWS APIs for services that support CloudTrail, the source IP address the calls were made from, and when the calls occurred. You can identify which users and accounts called AWS for services that support CloudTrail, the source IP address the calls were made from, and when the calls occurred. You can integrate CloudTrail into applications using the API, automate trail creation for your organization, check the status of your trails, and control how administrators turn CloudTrail logging on and off.

Explanation

Resource-based permissions are permissions you attach directly to a resource. Resource-level permissions refer to the ability to specify not just what actions users can perform, but which resources they’re allowed to perform those actions on. Resource-based policies are inline only, not managed. You can specify resource-based permissions for Amazon S3 buckets, Amazon Glacier vaults, Amazon SNS topics, Amazon SQS queues, and AWS Key Management Service encryption keys.

Explanation

Backup and restore, as defined in the “Using Amazon Web Services for Disaster Recovery” white paper, is most like traditional off-site backup replication. You can leverage services such as Amazon S3 or Amazon Storage Gateway to provide a backup replication target and Amazon EC2 can be used to restore access to your applications. This strategy for disaster recovery is the slowest of all AWS DR strategies.

Explanation

Auto Scaling is an AWS service that allows you to increase or decrease the number of EC2 instances within your application’s architecture. With Auto Scaling, you create collections of EC2 instances, called Auto Scaling groups. You can create these groups from scratch, or from existing EC2 instances that are already in production

Explanation

STS is the “glue” that supports temporary access credentials for federation. If you are running code, AWS CLI, or Tools for Windows PowerShell commands inside an EC2 instance, you can take advantage of roles for Amazon EC2. Otherwise, you can call an AWS STS API to get the temporary credentials, and then use them explicitly to make calls to AWS services.

Explanation

A placement group is a logical grouping of instances within a single Availability Zone. Cluster placement groups are recommended for applications that benefit from low network latency, high network throughput, or both. To provide the lowest latency, and the highest packet-per-second network performance for your cluster placement group, choose an instance type that supports enhanced networking

Explanation

If an IAM user wants to launch an EC2 instance, you need to grant the EC2 RunInstance permission to that user. If the EC2 instance should include an instance profile—that is, if applications in the EC2 instance will be able to get temporary security credentials via an IAM role—the user who launches the EC2 instance must also have the IAM PassRole permission. Not only that, but the user might need PassRole permission to associate a specific role with the EC2 instance.

Explanation

Amazon EC2 allows the user to launch On-Demand instances. Auto Scaling offers automation which can scale up or down resources as per the configured policy.

To set up Auto Scaling, the organization must first create an AMI. The organization should set up bootstrapping for the AMI so that when the instance is launched, it will automatically start the app server and DB server.

The organization should also setup ELB with instances to distribute the incoming load. Auto Scaling should be configured to scale up and down based on the application load and not on a particular schedule.

Explanation

SQS allows you to quickly build hosted and scalable message queuing applications that can run on any computer. SQS stores messages in transit between diverse, distributed application components without losing messages and without requiring each component to be always available

Explanation

Regarding Amazon Route 53, if your application is running on Amazon EC2 instances in two or more Amazon EC2 regions, and if you have more than one Amazon EC2 instance in one or more regions, you can use latency-based routing to route traffic to the correct region and then use weighted resource record sets to route traffic to instances within the region based on weights that you specify

Explanation

When scaling a database, you can increase the storage capacity of a DB Instance up to a maximum of 64 terabytes (TiB). Please note that scaling the storage allocation with Amazon RDS does not incur a database outage. The performance will be increased as well.

Explanation

When you create a bucket or object in Amazon S3, only you have access. To give control to others you can use course grained controls (Access Control Lists), and fine grained controls (bucket policies, IAM policies, and query-string authentication)

Explanation

Privacy laws in foreign countries will dictate compliance rules and regulations. AWS customers remain responsible for complying with applicable compliance laws and regulations.

Explanation

Several factors can affect the performance of Amazon EBS volumes, such as instance configuration, I/O characteristics, workload demand, and storage configuration. IOPS are input/output operations per second. Amazon EBS measures each I/O operation per second (that is 256 KB or smaller) as one IOPS. I/O operations that are larger than 256 KB are counted in 256 KB capacity units. For example, a 1,024 KB I/O operation would count as 4 IOPS. When you provision a 4,000 IOPS volume and attach it to an EBS-optimized instance that can provide the necessary bandwidth, you can transfer up to 4,000 chunks of data per second (provided that the I/O does not exceed the 128 MB/s per volume throughput limit of General Purpose (SSD) and Provisioned IOPS (SSD) volumes).

Explanation

By tagging all resources with the business unit and enabling detailed billing reports, you would enable the finance team to run cost reports by business unit.

Explanation

When you send a request to initiate a multipart upload, Amazon S3 returns a response with an upload ID, which is a unique identifier for your multipart upload. You must include this upload ID whenever you upload parts, list the parts, complete an upload, or abort an upload. When uploading a part, in addition to the upload ID, you must specify a part number that uniquely identifies a part and its position in the object you are uploading. Amazon S3 returns an ETag header in its response. For each part upload, you must record the part number and the ETag value for use in each subsequent request.

Explanation

The user cannot authorize an Amazon EC2 security group if it is in a different AWS Region than the RDS DB instance. The user can authorize an IP range or specify an Amazon EC2 security group in the same region that refers to an IP address in another region. In this case allow IP of US West inside US East’s security group and open the RDS security group for US East region.

Explanation

When you force a failover of your DB instance, Amazon RDS automatically switches to a standby replica in another Availability Zone if you have enabled Multi-AZ. The time it takes for the failover to complete depends on the database activity and other conditions at the time the primary DB instance became unavailable. Failover times are typically 60-120 seconds. However, large transactions or a lengthy recovery process can increase failover time. When the failover is complete, it can take additional time for the RDS console UI to reflect the new Availability Zone.

The failover mechanism automatically changes the DNS record of the DB instance to point to the standby DB instance. As a result, you will need to re-establish any existing connections to your DB instance.

Explanation

For an EC2 instance launched with an EBS backed Windows AMI, each time the instance state is changed from stop to start/ running, AWS charges restart a new per-hour charge. Effective October 2, 2017, charges are calculated on a per-second basis for On-Demand, Spot and Reserved instances with Linux operating systems, with a minimum one-minute charge. Regardless of operating system, rebooting an instance AWS does not incur a charge an hour or one-minute minimum charge.

Explanation

The CORS specification gives a user the ability to build web applications that make requests to domains other than the one which supplied the primary content. The ACLs and policies continue to apply when you enable CORS on the bucket.

Explanation

When you purchase a Reserved Instance, choose a payment option, term, and an offering class that suits your needs. Generally speaking, you can save more money choosing Reserved Instances with a higher upfront payment. There are three payment options (No Upfront, Partial Upfront, All Upfront), two-term lengths (one-year or three-years), and two offering classes (Convertible and Standard). Convertible RIs offer up to a 55% discount, while Standard offers up to a 75% discount. No Upfront and Partial Upfront Reserved Instances are billed for usage on an hourly basis, regardless of whether they are being used. All Upfront Reserved Instances have no additional hourly charges.

Explanation

To handle a higher load in your database, you can vertically scale up your master database with a simple push of a button. There are currently over 18 instance sizes that you can choose from when resizing your RDS MySQL, PostgreSQL, MariaDB, Oracle, or Microsoft SQL Server instance. For Amazon Aurora, you have 5 memory-optimized instance sizes to choose from. There is minimal downtime when you are scaling up on a Multi-AZ environment because the standby database gets upgraded first, then failover will occur to the newly sized database. A Single-AZ instance will be unavailable during the scale operation

Explanation

SQS provides several advantages over building your own software for managing message queues that require significant up-front time for development and configuration. Homegrown solutions require ongoing hardware maintenance and system administration resources. The complexity of configuring and managing these systems is compounded by the need for redundant storage of messages that ensures messages are not lost if hardware fails. In contrast, Amazon SQS requires no administrative overhead and little configuration. SQS works on a massive scale, processing billions of messages per day. You can scale the amount of traffic you send to Amazon SQS up or down without any configuration. Amazon SQS also provides extremely high message durability.

Explanation

Establish a private connection from your new office’s network to your Amazon VPC using AWS Direct Connect is the most suitable option in this case. This option provides predictable network performance, reduces bandwidth costs, and doesn’t require that customers be responsible for implementing high availability solutions for all VPN endpoints. The downside of this option (possible requiring additional telecom and hosting provider relationships) is mitigated in this instance because the office is new and would need to provision a whole new network anyway.

Explanation

If you use PuTTY to connect to your instances verify that your private key (.pem) file has been converted to the format recognized by PuTTY (.ppk). PuTTY does not natively support the private key format (.pem) generated by Amazon EC2. PuTTY has a tool named PuTTYgen, which can convert keys to the required PuTTY format (.ppk). You must convert your private key into this format (.ppk) before attempting to connect to your instance using PuTTY.

Explanation

Check the network access control list (ACL) for the subnet. The network ACLs must allow inbound and outbound traffic from your local IP address on the proper port. The default network ACL allows all inbound and outbound traffic. To enable Internet access for the EC2 instances in a VPC, you must create an Internet Gateway as well as a route to it in the router table.

Explanation

Amazon SNS and CloudWatch are integrated so you can collect, view, and analyze metrics for every active Amazon SNS notification. By configuring CloudWatch for Amazon SNS, you can gain better insight into the performance of your Amazon SNS topics, push notifications, and SMS deliveries.

Explanation

Amazon Route 53 lets you configure DNS failover in active-active, active-passive, and mixed configurations to improve the availability of your application. When you have more than one resource performing the same function, you can configure Amazon Route 53 to check the health of your resources and respond to DNS queries using only the healthy resources.

Another solution would be to assign an elastic IP address to the EC2 instance and have a backup instance running. In the event of failure, move the Elastic IP from the primary instance to the backup instance.

Explanation

Amazon Simple Queue Service (SQS) is a highly reliable distributed messaging system for storing messages as they travel between computers. By using Amazon SQS, developers can simply move data between distributed application components. It is used to achieve compartmentalization or loose coupling. In this case all the modules will send a message to the logger queue and the data will be processed by queue as per the resource availability.

Explanation

As with all Amazon Web Services, you pay only for what you use. For Elastic Load Balancing, you pay for each hour or portion of an hour that the service is running, and you pay for each gigabyte of data that is transferred through your load balancer.

Explanation

Yes, to create a snapshot for Amazon EBS volumes that serve as root devices, you should stop the instance before taking the snapshot.

Explanation

When you create a snapshot of a Throughput Optimized HDD (st1) or Cold HDD (sc1) volume, performance may drop as far as the volume’s baseline value while the snapshot is in progress. This behavior is specific to these volume types.

Explanation

OpsWorks stacks will let you utilize your existing Chef recipes, but only OpsWorks for Chef Automate will provide you with centralized, continuous configuration management.

Explanation

A route table contains a set of rules, called routes, that are used to determine where network traffic is directed.

Each subnet in your VPC must be associated with a route table; the table controls the routing for the subnet. A subnet can only be associated with one route table at a time, but you can associate multiple subnets with the same route table. When you add an Internet gateway, an egress-only Internet gateway, a virtual private gateway, a NAT device, a peering connection, or a VPC endpoint in your VPC, you must update the route table for any subnet that uses these gateways or connections.

Explanation

Amazon RDS Read Replicas provide enhanced performance and durability for database (DB) instances. This replication feature makes it easy to elastically scale out beyond the capacity constraints of a single DB Instance for read-heavy database workloads. You can create one or more replicas of a given source DB Instance and serve high-volume application read traffic from multiple copies of your data, thereby increasing aggregate read throughput. Read replicas can also be promoted when needed to become standalone DB instances.

Read replicas in different regions are available in Amazon RDS for MYSQL, MariaDB, PostgreSQL, Oracle, and Aurora