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

Explanation

You can reduce EC2 spend by migrating to reserved/spot instances, eliminating/shrinking unused resources, or consolidating AWS accounts (to qualify for volume discounts). The paying account’s use of consolidated billing can benefit from volume pricing discounts gained thru aggregate account usage.

Explanation

You can use snapshots to increase the size of EBS volumes. Take a snapshot of the existing volume, create a new volume from the snapshot but with a larger size, then replace the original snapshot with the new volume. There is a performance hit with new volumes because, while the volume is created immediately, the data is lazy loaded. So there will be a first time performance hit when accessing each block on the volume. This problem can be resolved by initializing the volume and accessing each block one time before the volume is put into service.

Explanation

If your volume stays in the detaching state, you can force the detachment by clicking Force Detach

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

Instances that you launch into a default subnet receive both a public IP address and a private IP address. Instances in a default subnet also receive both public and private DNS hostnames. Instances that you launch into a nondefault subnet in a default VPC don’t receive a public IP address or a DNS hostname. You can change your subnet’s default public IP addressing behavior

Explanation

The user can join multiple provisioned IOPS volumes together in a RAID 1 configuration to achieve better fault tolerance. RAID 1 does not provide a write performance improvement, it requires more bandwidth than non-RAID configurations since the data is written simultaneously to multiple volumes.

Explanation

AWS will choose the most specific route first. If routes are equal after checking for the most specific routes, AWS will use AS path prepending to determine which route is preferred. In this example, 10.20.30.0/25 is more specific than 10.20.30.0/24 and 10.20.0.0/16, so AS path prepending will not matter. The other options are either outside of the address range in question (10.20.30.128/26 and 10.20.128.0/17) or less specific than the route advertised by Houston (10.20.30.0/23). The route advertised from Orlando, 10.20.30.254/32, identifies a single IPv4 address that is outside of the range in question

Explanation

To configure a bucket for static website hosting, you add a website configuration to your bucket. The configuration includes an index document, error documents, redirects of all requests that are intended for the index page, and any conditional redirects. Amazon S3 does not support server-side scripting.

Explanation

A cluster placement group is a logical grouping of instances within a single AWS 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

Explanation

Amazon SQS is a distributed queuing system that is optimized for horizontal scalability, not for single-threaded sending or receiving speeds. A single client can send or receive Amazon SQS messages at a rate of about 5 to 50 messages per second. Higher receive performance can be achieved by requesting multiple messages (up to 10) in a single call. It may take several seconds before a message that has been to a queue is available to be received.

Explanation

For the SSH agent forwarding to be successful, both security groups need to allow connection via port 22. Custom security groups by default allow all outbound traffic, but deny all inbound traffic.

Explanation

Amazon Simple Email Service (Amazon SES) is a highly scalable and cost-effective email-sending service for businesses and developers. It integrates with other AWS services, making it easy to send emails from applications that are hosted on AWS

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

AWS Storage Gateway enables applications that are clustered using Windows Server Failover Clustering (WSFC) to use the iSCSI initiator to access a gateway’s volumes. However, connecting multiple hosts to the same iSCSI target is not supported. When using Red Hat Enterprise Linux (RHEL), you use the iscsi-initiator-utils RPM package to connect to your gateway iSCSI targets (volumes or VTL devices).

Explanation

In Amazon Web Services, the spot instance is useful when the user wants to run a process temporarily. The spot instance can terminate the instance if the other user outbids the existing bid. In this case all storage is temporary and the data is not required to be persistent. Thus, the spot instance is a good option to save money

Explanation

The key benefit of launch templates is their capability to support multiple instance types and purchase types within the same template.

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

Amazon RDS manages the work involved in setting up a relational database: from provisioning the infrastructure capacity you request to installing the database software. Once your database is up and running, Amazon RDS automates common administrative tasks such as performing backups and patching the software that powers your database. With optional multi-AZ deployments, Amazon RDS also manages synchronous data replication across Availability Zones with automatic failover.

Since Amazon RDS provides native database access, you interact with the relational database software as you normally would. This means you’re still responsible for managing the database settings that are specific to your application. You’ll need to build the relational schema that best fits your use case and are responsible for any performance tuning to optimize your database for your application’s workflow.

Explanation

An elastic network interface is a virtual network interface that you can attach to an instance in a VPC. Network interfaces are available only for instances running in a VPC.  If one of your instances serving a particular function fails, its network interface can be attached to a replacement or hot standby instance pre-configured for the same role to rapidly recover the service.

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

An Elastic IP address is associated with your AWS account. With an Elastic IP address, you can mask the failure of an instance or software by rapidly remapping the address to another instance in your account. You can disassociate an Elastic IP address from a resource, and reassociate it with a different resource. A disassociated Elastic IP address remains allocated to your account until you explicitly release it. An Elastic IP address is for use in a specific region only.

Explanation

In Amazon Route 53, you cannot create a hosted zone for a top-level domain (TLD).

Explanation

AWS CloudFormation is a service that helps you model and set up your Amazon Web Services resources so that you can spend less time managing those resources and more time focusing on your applications that run in AWS. You create a template that describes all the AWS resources that you want (like Amazon EC2 instances or Amazon RDS DB instances), and AWS CloudFormation takes care of provisioning and configuring those resources for you. A template is a JSON-formatted text file that describes your AWS infrastructure. Templates include several major sections. The Resources section is the only section that is required. The first character in the template must be an open brace ({), and the last character must be a closed brace (}). The following template fragment shows the template structure and sections

Explanation

Storage gateways interact with AWS over the public Internet or direct connect. You will need to know the amount of data per day that needs to be transferred to Amazon S3 and the net available bandwidth of your network connection. Storage Gateway is capable of running data compression, and comparison so only changed data is being backed up.

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

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

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

You can set up a variety of failover configurations using Amazon Route 53 alias: weighted, latency, geolocation routing, and failover resource record sets.

• Active-active failover: Use this failover configuration when you want all of your resources to be available the majority of the time. When a resource becomes unavailable, Amazon Route 53 can detect that it’s unhealthy and stop including it when responding to queries.
  Active-passive failover: Use this failover configuration when you want a primary group of resources to be available the majority of the time and you want a secondary group of resources to be on standby in case all of the primary resources become unavailable. When responding to queries, Amazon Route 53 includes only the healthy primary resources. If all of the primary resources are unhealthy, Amazon Route 53 begins to include only the healthy secondary resources in response to DNS queries.
• Active-active-passive and other mixed configurations: You can combine alias and non-alias resource record sets to produce a variety of Amazon Route 53 behaviors.

Explanation

Instances associated with a security group can’t talk to each other unless you add rules allowing it (exception: the default security group has these rules by default). By default, a security group includes an outbound rule that allows all outbound traffic. You can remove the rule and add outbound rules that allow specific outbound traffic only. If your security group has no outbound rules, no outbound traffic is allowed.

Explanation

Default security groups and NACLs allow inbound and outbound traffic. All traffic should be routed via internet gateway, so a route should be created with 0.0.0.0/0 as a source, and with your Internet Gateway as the target.

Explanation

The key is that the requirement is for high availability at the web-tier. While multi-AZ deployments and cross-region replication can contribute to high availability, they are each at the storage tier. Route 53 with Health Checks and Failover, Elastic Load Balancer (with health checks and various forms of load balancing, and auto scaling groups create high availability at the web tier.

Explanation

By default, a target starts to receive its full share of requests as soon as it is registered with a target group and passes an initial health check. Using slow start mode gives targets time to warm up before the load balancer sends them a full share of requests.

Increasing the maximum threshold for your auto scaling group will allow you to process more requests.

Explanation

The ability to pause multipart uploads offers great flexibility in its usage. A pause could be initiated for a number of reasons but pausing to relieve network traffic is a prime use case. If a multipart upload aborts, it is good practice to have a lifecycle policy, which will delete incomplete uploads after a predetermined number of days. This will reduce storage costs.

Explanation

Creating separate VPC Peering connections between each VPC is required for Peering 3 VPCs together. Transitive routing is not supported in VPC Peering so VPC C could not reach VPC A through VPC B. A new VPC Peering connection is required for connecting additional VPCs, so connecting VPC A to pcx-abcxyz is not a viable option. Adding a static route to VPC A that points to pcx-abcxyz would not work as pcx-abcxyz is not connected to VPC A.

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

Amazon Redshift is a fast, fully managed data warehouse that makes it simple and cost-effective to analyze all your data using standard SQL and your existing Business Intelligence (BI) tools. It allows you to run complex analytic queries against petabytes of structured data, using sophisticated query optimization, columnar storage on high-performance local disks, and massively parallel query execution.

Explanation

Amazon RDS provides high availability and failover support for DB instances using Multi-AZ deployments. Multi-AZ deployments for Oracle, PostgreSQL, MySQL, and MariaDB DB instances use Amazon technology, while SQL Server DB instances use SQL Server Mirroring.

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

If you are looking to use replication to increase database availability while protecting your latest database updates against unplanned outages, consider running your DB instance as a Multi-AZ deployment. When you create or modify your DB instance to run as a Multi-AZ deployment, Amazon RDS will automatically provision and manage a “standby” replica in a different Availability Zone (independent infrastructure in a physically separate location). In the event of planned database maintenance, DB instance failure, or an Availability Zone failure, Amazon RDS will automatically failover to the standby so that database operations can resume quickly without administrative intervention. Multi-AZ deployments utilize synchronous replication, making database writes concurrently on both the primary and standby so that the standby will be up-to-date in the event a failover occurs.

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

In this case the alarm watches a metric every 5 minutes for 10 intervals. Thus, it needs at least 50 minutes to come to the “OK” state. Till then it will be in the INSUFFUCIENT_DATA state. Since 90 minutes have passed and CPU utilization is at 80% constant, the state of alarm will be “ALARM”.

Explanation

Amazon SQS is a distributed queuing system that is optimized for horizontal scalability, not for single-threaded sending or receiving speeds. A single client can send or receive Amazon SQS messages at a rate of about 5 to 50 messages per second. Higher receive performance can be achieved by requesting multiple messages (up to 10) in a single call. It may take several seconds before a message that has been to a queue is available to be received.

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

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

Amazon S3 supports client side or server side encryption to encrypt all data at rest. The server side encryption can either have the S3 supplied AES-256 encryption key, or the user can send the key along with each API call to supply his own encryption key (SSE-C). If the bucket is versioning-enabled, each object version uploaded by the user using the SSE-C feature can have its own encryption key. The user is responsible for tracking which encryption key was used for which object’s version

Explanation

Amazon S3 Glacier Deep Archive storage class is the cheapest storage class in AWS, and the information can be retrieved within 12 hours.

The other options offer some cost savings compared to Amazon S3 Standard storage class, but Intelligent tiering would not cycle the files to an archive storage class for roughly 120 days, and the One Zone-IA storage class would provide some cost savings, but offers less durable storage, so the likelihood of losing logs is higher.

Explanation

The Warm Standby scenario uses a scaled-down version of a fully functional environment that is always running. Business-critical applications can always be running in the cloud. When a DR scenario comes about, the servers can be quickly scaled up, scaled out or both, but horizontal scaling is preferred over vertical scaling.

The two incorrect choices will increase your environment’s resilience by adding availability

Explanation

Auto Scaling can start and stop the instance at a pre-defined time. Here, the total running time is unknown. Thus, the user has to use the CloudWatch alarm, which monitors the CPU utilization. The user can create an alarm that is triggered when the average CPU utilization percentage has been lower than 10 percent for 24 hours, signaling that it is idle and no longer in use. When the utilization is below the threshold limit, it will terminate the instance as a part of the instance action.

Explanation

It is best practice to enable automatic backups and set the backup window to occur during the daily low in write IOPS. Amazon RDS creates automated backups of your DB instance during the backup window of your DB instance. Amazon RDS saves the automated backups of your DB instance according to the backup retention period that you specify. If necessary, you can recover your database to any point in time during the backup retention period.

Explanation

With AWS IAM a user is creating an application which runs on an EC2 instance and makes requests to AWS, such as DynamoDB or S3 calls. Here it is recommended that the user should not create an IAM user and pass the user’s credentials to the application or embed those credentials inside the application. Instead, the user should use roles for EC2 and give that role access to DynamoDB /S3. When the roles are attached to EC2, it will give temporary security credentials to the application hostedon that EC2, to connect with DynamoDB / S3.

Explanation

The technical requirements are file servers running Windows Server 2012 R2 and an Active Directory Schema of at least Server 2008 R2.

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

You grant AWS Lambda permission to access a DynamoDB Stream using an IAM role known as the “execution role”.

Explanation

There are essentially three types of answers here – choices that use no automation, choices that use the incorrect type of automation given the situation, and a choice that uses the correct type of automation.

First, the choices that use little to no automation in this case would be the least recommended decision. Uploading millions of files to either Standard or Standard-IA and then waiting to review costs and access patterns could be very costly.

Second, the choice to use storage class analysis could work eventually, if you have the time to wait for analytics to be gathered (which could still be as costly as the choice above) and the time to then review the analytics, and then sift through the files to migrate them to the correct storage class. This is a better choice, but not the best choice.

Finally, the correct answer would be to use Intelligent_Tiering, which continuously monitors the access frequency and shifts the objects between a standard and infrequent-access tier depending on how access patterns may change. This happens automatically, and starts immediately, so it is the best choice of the options provided.

Explanation

Explanation

Your VPC automatically comes with a default security group. Each EC2 instance that you launch in your VPC is automatically associated with the default security group if you don’t specify a different security group when you launch the instance.  The default security group disallows all inbound traffic and allows all outbound traffic. However, the rules for a default security group can be changed.

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

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

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

You are billed per-second with a one-minute minimum for On-Demand, Spot and Reserved instances as long as your EC2 instance is in a running state, provided the instance is Linux (with some exceptions), and not a Windows operating system, in which case the instance would be billed per-hour.

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

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

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

For internal communication between S3 and an application running on EC2 instance, you need two policies:

1. An IAM trust policy that allows the EC2 instance to assume a role
2. An IAM policy or S3 bucket policy that allows the role to get/put objects to the specific bucket

So, the kind of policies that control access to S3 bucket are either an IAM Policy or S3 Bucket Policy. The IAM trust policy is required, but it doesn’t control access to S3.

Explanation

Creating a custom AMI of the instance for which you are trying to provide HA allows you to bring the instance online quickly with no build time. Moving the EIP from the instance, you are replacing to the new instance will send all traffic to the new instance without any change to DNS, which would take time to propagate. Using the AutoRecover option will not replace the unhealthy or failing instance. It will only try to restart it on another host. Creating a “Steady State” Auto Scaling Group would also be a good solution, although using two as a minimum would have a higher cost.

Explanation

By using Amazon S3 analytics storage class analysis you can analyze storage access patterns to help you decide when to transition the right data to the right storage class. This new Amazon S3 analytics feature observes data access patterns to help you determine when to transition less frequently accessed STANDARD storage to the STANDARD_IA (IA, for infrequent access) storage class.

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

You can create an Auto Scaling group directly from an EC2 instance. When you use this feature, Auto Scaling automatically creates a launch configuration for you as well.

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

Amazon CloudWatch provides the functionality to graph the metric data generated either by the AWS services or the custom metric to make it easier for the user to analyse. The AWS CloudWatch console provides the option to change the granularity of a graph and zoom in to see data over a shorter time period. To zoom, the user has to click in the graph details pane, drag on the graph area for selection, and then release the mouse button.

Explanation

The Elastic Load Balancer can integrate with the AWS Certificate Manager to provide a central method of managing your TLS/SSL certificates. It allows you to renew, deploy and configure your TLS/SSL certificates for your application or website from a single location.

Explanation

Issues that are not first solved locally will not be solved by moving to the cloud. Moving to the cloud is not a silver bullet. If there are inherent problems in the existing architecture there is no guarantee that they will be solved by moving to the cloud. Try to resolve any issues locally before migrating your architecture (and its existing issues) to the cloud.

Explanation

Amazon RDS manages the work involved in setting up a relational database: from provisioning the infrastructure capacity you request to installing the database software. Once your database is up and running, Amazon RDS automates common administrative tasks such as performing backups and patching the software that powers your database. With optional multi-AZ deployments, Amazon RDS also manages synchronous data replication across Availability Zones with automatic failover.

Since Amazon RDS provides native database access, you interact with the relational database software as you normally would. This means you’re still responsible for managing the database settings that are specific to your application. You’ll need to build the relational schema that best fits your use case and are responsible for any performance tuning to optimize your database for your application’s workflow.

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

EC2 Auto Recovery can detect any condition that will cause a system status check to fail, including hypervisor problems or loss of power/network connectivity.

Explanation

A security group controls the access to a DB instance. It does so by allowing access to IP address ranges or Amazon EC2 instances that you specify. Amazon RDS uses DB security groups, VPC security groups, and EC2 security groups. In simple terms, a DB security group controls access to a DB instance that is not in a VPC, a VPC security group controls access to a DB instance inside a VPC, and an Amazon EC2 security group controls access to an EC2 instance and can be used with a DB instance.