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

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

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

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

Amazon S3 stores objects according to their storage class. There are technically four major storage classes: Standard, Standard – Infrequent Access, Reduced Redundancy Storage (RRS) and Glacier.

Standard is for Amazon S3 and provides very high durability. Standard – Infrequent Access is designed for with a minimum data amount required and paid storage for at least 30 days. Glacier is for archival and the files are not available over the internet. Reduced Redundancy Storage is for less critical files.

S3 OneZone IA is a variation of Standard-IA, which offers data archival at a reduced price, but also with less durability because the data within this class is stored within a single availability zone rather than spread throughout all availability zones within the S3 buckets region, as it is with S3 Standard storage.

Explanation

AWS Storage Services are: Amazon S3 Amazon Glacier Amazon EBS AWS Storage Gateway

Explanation

T2 instances are Burstable Performance Instances that provide a baseline level of CPU performance with the ability to burst above the baseline. The baseline performance and ability to burst are governed by CPU Credits. M4 instances are the latest generation of General Purpose Instances. This family provides a balance of compute, memory, and network resources, and it is a good choice for many applications. In this instance, the only option which provides for growth while keeping costs in check is to upgrade to reserved M4 instances on a long term 3 year contract.

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

Amazon API Gateway automatically protects your backend systems from distributed denial-of-service (DDoS) attacks, whether attacked with counterfeit requests (Layer 7) or SYN floods (Layer 3). Additional reading is available here (https://aws.amazon.com/api-gateway/faqs/).

AWS Shield Advanced includes intelligent DDoS attack detection and mitigation for not only for the network layer (layer 3) and transport layer (layer 4) attacks but also for application layer (layer 7) attacks.

NACLs do not provide DDoS mitigation. They are used to control ingress and egress into a subnet based on port and source IP range. Route 53 can protect against DNS based DDoS attacks but does not protect entire layers. Elastic Load Balancing can protect EC2 instances specifically, but not other AWS resources.

Explanation

AWS is responsible for what is known as Security ‘of’ the Cloud. This covers their global infrastructure elements – Regions, Availability Zones, and Edge Locations, and also the foundations of their services covering Compute, Storage, Database, and Network

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

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

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

The default maximum number of Access Keys per user is 2

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

A principal is an IAM entity that is allowed to interact with AWS resources. The Principal element specifies the user, account, service, or other entity that is allowed or denied access to a resource. The Principal element is relevant only in a bucket policy; you don’t specify it in a user policy because you attach user policy directly to a specific user.

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

A security group acts as a virtual firewall for your instance to control inbound and outbound traffic. When you launch an instance in a VPC, you can assign the instance to up to five security groups. Security groups act at the instance level, not the subnet level. Therefore, each instance in a subnet in your VPC could be assigned to a different set of security groups. If you don’t specify a particular group at launch time, the instance is automatically assigned to the default security group for the VPC. If an instance is running in an Amazon VPC you can change which security groups are associated with an instance while the instance is running.

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.

The Multi AZ feature allows the user to achieve High Availability. For Multi AZ, Amazon RDS automatically provisions and maintains a synchronous “standby” replica in a different Availability Zone.

Explanation

Within Amazon EC2, when using a Linux instance, the device name /dev/sda1 is reserved for the root device.

Explanation

Enabling the Multi-AZ option provides high availability and failover support for the replication instance

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

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

Running a DB Instance as a Multi-AZ deployment can further reduce the impact of a maintenance event because Amazon RDS will conduct maintenance by following these steps: Perform maintenance on the standby.

Explanation

Implementing a Route 53 Calculated Health Check is the best solution in this case because it aggregates all of the individual health checks. Integrating QuickSight and CloudTrail will create an effective dashboard, but this is not an automated solution because someone has to continuously check the dashboard.

You can also create a CloudWatch Log log alarm, but this would be overly complex compared to the Calculated Health Checks.

For example, let’s say you have deployed 15 EC2 instances, and created 15 separate Route 53 health checks to monitor each one. While you are concerned about each instance’s performance, you essentially need 10 of the 15 instances to be healthy for your system to run properly. Rather than setting up SNS notifications for each individual health check, you can create a calculated health check that collects the results of each health check into a single count between 0-15, and compares that count to a threshold you’ve set. In this case, the threshold could be 10. Now, if 10 instances are healthy, the calculated health check comes back healthy. If less than 10 instances are healthy, the health check comes back unhealthy.For example, let’s say you have deployed 15 EC2 instances, and created 15 separate Route 53 health checks to monitor each one. While you are concerned about each instance’s performance, you essentially need 10 of the 15 instances to be healthy for your system to run properly. Rather than setting up SNS notifications for each individual health check, you can create a calculated health check that collects the results of each health check into a single count between 0-15, and compares that count to a threshold you’ve set. In this case, the threshold could be 10. Now, if 10 instances are healthy, the calculated health check comes back healthy. If less than 10 instances are healthy, the health check comes back unhealthy.

Explanation

The Elastic Beanstalk option is incorrect because it requires a constantly-polling instance, which may break and costs money.

The Lambda fleet option is incorrect because AWS Lambda does not support GPU usage.

The OpsWorks stack option both requires a constantly-polling instance, and also requires complex timing and capacity planning logic.

The CloudFormation option requires no polling, has no always-on instances, and allows arbitrarily fast processing by simply setting the instance count as high as needed.

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

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 allof 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

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 EBS provides three volume types: General Purpose SSD, Provisioned IOPS SSD, and Magnetic.

General Purpose SSD volumes are the default EBS volume type for Amazon EC2 instances.

GP2 volumes smaller than 1 TB can burst up to 3,000 IOPS. I/O is included in the price of gp2, so you pay only for each GB of storage you provision. GP2 is designed to deliver the provisioned performance 99% of the time. If you need a greater number of IOPS than gp2 can provide, or if you have a workload where low latency is critical or you need better performance consistency, we recommend that you use io1.

Explanation

Recovery takes IOPS; therefore, insufficient IOPS will slow down failover time. Database recovery relies on transactions; therefore, smaller transactions will shorten failover time.

Explanation

An EBS volume is off-instance storage that can persist independently from the life of an instance. You continue to pay for the volume usage as long as the data persists. EBS instances can be stopped and re-started. And EBS volumes boot faster than instance store volumes often by an order of magnitude

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

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

Your VPC has an implicit router and a main route table that you can modify. Each subnet you create must be associated with a route table. Adding an internet gateway and adding a route to that IGW facilitates traffic out to the Internet for a public subnet. NAT instance and NAT gateways are provided to allow instances in private subnets to gain internet access

Explanation

Enhanced networking uses single root I/O virtualization (SR-IOV) to provide high-performance networking capabilities on supported instance types. SR-IOV is a method of device virtualization that provides higher I/O performance and lower CPU utilization when compared to traditional virtualized network interfaces. Enhanced networking provides higher bandwidth, higher packet per second (PPS) performance, and consistently lower inter-instance latencies.

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

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

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

Auto scaling provides redundancy for a single server with the option of launching a configuration using the attributes from a running instance. When you use this option, auto scaling copies the attributes from the specified instance into a template from which you can launch one or more auto scaling groups.

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

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

To handle a higher load in your database, you can vertically scale up your master database. Before you scale, make sure you have the correct licensing in place for commercial engines (SQL Server, Oracle) especially if you Bring Your Own License (BYOL). One important thing to call out is that for commercial engines, you are restricted by the license, which is usually tied to the CPU sockets or cores.

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

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

Application Load Balancer
You are charged for each hour or partial hour that an Application Load Balancer is running and the number of Load Balancer Capacity Units (LCU) used per hour.

Network Load Balancer
You are charged for each hour or partial hour that a Network Load Balancer is running and the number of Load Balancer Capacity Units (LCU) used by Network Load Balancer per hour.

Classic Load Balancer
You are charged for each hour or partial hour that a Classic Load Balancer is running and for each GB of data transferred through your load balancer.

Explanation

An Elastic Load Balancer(ELB) by default, routes each request independently to the application instance with the smallest load. However, you can use the sticky session feature (also known as session affinity), which enables the load balancer to bind a user’s session to a specific application instance. This ensures that all requests coming from the user during the session will be sent to the same application instance. The key to managing the sticky session is determining how long your load balancer should consistently route the user’s request to the same application instance. If your application has its own session cookie, then you can set Elastic Load Balancing to create the session cookie to follow the duration specified by the application’s session cookie. If your application does not have its own session cookie, then you can set Elastic Load Balancing to create a session cookie by specifying your own stickiness duration. You can associate stickiness duration for only HTTP/HTTPS load balancer listeners. An application instance must always receive and send two cookies: A cookie that defines the stickiness duration and a special Elastic Load Balancing cookie named AWSELB, that has the mapping to the application instance.

Explanation

When you create a VPC, you must specify a range of IPv4 addresses for the VPC in the form of a Classless Inter-Domain Routing (CIDR) block; for example, 10.0.0.0/16. The first four IP addresses and the last IP address in each subnet CIDR block are not available for you to use, and cannot be assigned to an instance. AWS reserves the first four addresses and the last address in a CIDR block, so be sure to subtract five to give the number of addresses in a CIDR block available for use

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

The organization can always launch multiple EC2 instances in the same region across multiple availability zones for high availability and disaster recovery. It is recommended that the application should be load balanced for better load distribution. When the organization must support a workload that could be met with a small number of large instances, it is recommended to distribute the load by creating four small instances across availability zones. The two large instances give only 50% redundancy while the four small instances give 75% redundancy. As for cost, both the scenarios are the same it is recommended to run four small instances across availability zones

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

You can create a VPC Gateway Endpoint to allow resources within a VPC to connect to DynamoDB without network communication extending outside your own VPC.

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

The path functionality within an IAM group and user allows them to delineate by further levels. In this case, the user needs to use the path with each user or group so that the ARN of the user will look similar to:

• arn:aws:iam::123456789012:user/division_abc/subdivision_xyz/user1
• arn:aws:iam::123456789012:user/division_abc/subdivision_xyz/user2

Explanation

An archive is a durably stored block of information. You store your data in Amazon Glacier as archives. You may upload a single file as an archive, but your costs will be lower if you aggregate your data. TAR and ZIP are common formats that customers use to aggregate multiple files into a single file before uploading to Amazon Glacier. The total volume of data and number of archives you can store are unlimited. Individual Amazon Glacier archives can range in size from 1 byte to 40 terabytes. The largest archive that can be uploaded in a single upload request is 4 gigabytes. For items larger than 100 megabytes, customers should consider using the Multipart upload capability. Archives stored in Amazon Glacier are immutable, i.e. archives can be uploaded and deleted but cannot be edited or overwritten.

Explanation

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

To prevent the public DNS address for your instance from changing and breaking your installation, you can associate an Elastic IP address (EIP) to the instance you are using. You need to allocate an Elastic IP address for that instance (the first association is free). If you own a domain name and you want to use it for your blog, you can update the DNS record for the domain name to point to your EIP address. If you don’t already have a domain name for your blog, you can register a domain name with Amazon Route 53 and associate your instance’s EIP address with your domain name.

Explanation

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

Explanation

After you turn on S3 Transfer Acceleration for a bucket, two new endpoints are created for the bucket: one for IPv4 and one for IPv6. You can use either the accelerate endpoints or the standard endpoints if you choose not to use the accelerate feature.

Explanation

Amazon Web Services has massive hardware resources at its data centers, but they are finite. The best way for users to maximize their access to these resources is by reserving a portion of the computing capacity that they require. This can be done through reserved instances. With reserved instances, the user literally reserves the computing capacity in the Amazon Web Services cloud.

Explanation

With Amazon EBS, you can use any of the standard RAID configurations that you can use with a traditional bare metal server, as long as that particular RAID configuration is supported by the operating system for your instance. This is because all RAID is accomplished at the software level. For greater I/O performance than you can achieve with a single volume, RAID 0 can stripe multiple volumes together, for on-instance redundancy, RAID 1 can mirror two volumes together. RAID 5 and RAID 6 are not recommended for Amazon EBS because the parity write operations of these RAID modes consume some of the IOPS available to your volumes

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

Explanation

Both instance status checks and health checks must be enabled before unhealthy instances will be terminated. It is critical that you test not only the saturation and breaking points but also the “normal” traffic profile you expect

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

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

By launching your instances into a VPC instead of EC2-Classic, you gain the ability to: Assign static private IP addresses to your instances that persist across starts andstops Assign multiple IP addresses to your instances. Define network interfaces, and attach one or more network interfaces to your instances Change security group membership for your instances while they’re running Control the outbound traffic from your instances (egress filtering) in addition to controlling the inbound traffic to them (ingress filtering). Add an additional layer of access control to your instances in the form of network access control lists (ACL). Run your instances on single-tenant hardware

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

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 Relational Database Service (Amazon RDS) is a managed service that makes it easy to set up, operate, and scale a relational database in the cloud. It provides cost-efficient and resizable capacity, while managing time-consuming database administration tasks, freeing you up to focus on your applications and business. When you create or modify your DB Instance to run as a Multi-AZ deployment, Amazon RDS automatically provisions and maintains a synchronous “standby” replica in a different Availability Zone. Updates to your DB Instance are synchronously replicated across Availability Zones to the standby in order to keep both in sync and protect your latest database updates against DB Instance failure. During certain types of planned maintenance, or in the unlikely event of DB Instance failure or Availability Zone failure, Amazon RDS will automatically failover to the standby so that you can resume database writes and reads as soon as the standby is promoted. Since the name record for your DB Instance remains the same, your application can resume database operation without the need for manual administrative intervention. With Multi-AZ deployments, replication is transparent: you do not interact directly with the standby, and it cannot be used to serve read traffic. If you are using Amazon RDS for MySQL and are looking to scale read traffic beyond the capacity constraints of a single DB Instance, you can deploy one or more Read Replicas

Explanation

Elastic Beanstalk environments can be changed after creation. For example, if you have a compute-intensive application, you can change the type of Amazon EC2 instance that is running your application. To do this, you use the Scaling option in the management page of the Elastic Beanstalk console and change the minimum instance count.