SOA-C01 : AWS-SysOps ​​​​​: Part 23

SOA-C01 : AWS-SysOps ​​​​​: Part 23

1. In AWS Storage Gateway, Gateway-cached volumes allow you to retain ________________.

   • a durable and inexpensive offsite backup that you can recover locally
   • your primary data locally, and asynchronously back up point-in-time snapshots of this data to Amazon S3
   • your backup application with online access to virtual tapes
   • low-latency access to your frequently accessed data

   Explanation:
   You store your data in Amazon S3 and retain a copy of frequently accessed data subsets locally.
   Gateway-cached volumes offer a substantial cost savings on primary storage and minimize the need to scale your storage on-premises. You also retain low-latency access to your frequently accessed data.

2. Which of the following states is not possible for the CloudWatch alarm?

   • ALERT
   • ALARM
   • OK
   • INSUFFICIENT_DATA
   Explanation:
   An alarm has 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

3. What is the default maximum number of VPCs allowed per region?

   • 5
   • 15
   • 100
   • 10
   Explanation:
   The maximum number of VPCs allowed per region is 5. The limit for Internet gateways per region is directly correlated to this one. Increasing this limit will increase the limit on Internet gateways per region by the same amount.

4. How often is metric data is sent to CloudWatch when detailed monitoring is enabled on an Amazon EC2 instance?

   • Every 30 seconds
   • Every 5 minutes
   • Every 15 minutes
   • Every minute
   Explanation:
   By default, Amazon EC2 metric data is automatically sent to CloudWatch in 5-minute periods.
   However, you can, enable detailed monitoring on an Amazon EC2 instance, which sends data to CloudWatch in 1-minute periods

5. A route table in VPC can be associated with multiple subnets. However, a subnet can be associated with only ______ route table(s) at a time.

   • four
   • two
   • three
   • one
   Explanation:
   Every subnet in your VPC must be associated with exactly one route table at a time. However, the same route table can be associated with multiple subnets.

6. Which of the following statements is NOT true of CloudWatch?

   • CloudWatch can be accessed using the AWS SDKS.
   • CloudWatch can be accessed using the AWS console.
   • CloudWatch can be accessed using CloudWatch API.
   • CloudWatch can be accessed using the CloudWatch CLI for iOS.
   Explanation:
   AWS Cloudwatch can be accessed from the Amazon CloudWatch Console, CloudWatch API, AWS CLI and AWS SDKs.

7. Which of the following is an incorrect statement about Amazon CloudWatch?

   • You can use CloudWatch to collect and track metrics, which are the variables you want to measure for your resources and applications.
   • You can set CloudWatch alarms to send notifications or automatically make changes to the resources you are monitoring, based on rules that you define.
   • You can control and monitor all Security Groups and their related rules.
   • You gain system-wide visibility into resource utilization, application performance, and operation-al health.
   Explanation:
   Amazon CloudWatch monitors your Amazon Web Services (AWS) resources and the applications
   you run on AWS in real-time.
   You can use CloudWatch to collect and track metrics, which are the variables you want to measure for your resources and applications. CloudWatch alarms send notifications or automatically make changes to the resources you are monitoring based on rules that you define. For example, you can monitor the CPU usage and disk reads and writes of your Amazon Elastic Compute Cloud (Ama-zon EC2) instances and then use this data to determine whether you should launch additional in-stances to handle increased load. You can also use this data to stop under-used instances to save money. In addition to monitoring the built-in metrics that come with AWS, you can monitor your own custom metrics. With CloudWatch, you gain system-wide visibility into resource utilization, application performance, and operational health.

8. Which of the following terms is NOT a key CloudWatch concept?

   • Namespaces
   • Units
   • Time Stamps
   • Indexes
   Explanation:
   The terminology and concepts that are central to one’s understanding and use of Amazon Cloud-Watch are as follows: metrics, namespaces, dimensions, timestamps, units, statistics, periods, aggre-gation, alarms, and regions.

9. Network ACLs in a VPC operate at the ______.

   • TCP level
   • instance level
   • subnet level
   • gateway level
   Explanation:
   Security Groups in VPC operate at the instance level, providing a way to control the incoming and outgoing instance traffic. In contrast, network ACLs operate at the subnet level, providing a way to control the traffic that flows through the subnets of your VPC.

10. Your VPC automatically comes with a modifiable default network ACL, which by default _____.

    • blocks outbound traffic
    • allows only inbound traffic
    • allows all inbound and outbound traffic
    • blocks all inbound and outbound traffic
    Explanation:
    Your VPC automatically comes with a modifiable default network ACL. By default, it allows all inbound and outbound traffic.

11. What is a placement group in Amazon EC2?

    • It is a logical grouping of EC2 instances within a single Availability Zone.
    • It the edge location of your web content.
    • It is a group used to span multiple Availability Zones.
    • It is the AWS region where you run the EC2 instance of your web content.
    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.

12. In which screen does a user select the Availability Zones while configuring Auto Scaling?

    • Auto Scaling Group Creation
    • Auto Scaling Instance Creation
    • Auto Scaling Launch config Creation
    • Auto Scaling Policy Creation
    Explanation:
    You can take advantage of the safety and reliability of geographic redundancy by spanning your Auto Scaling group across multiple Availability Zones within a region and then attaching a load bal-ancer to distribute incoming traffic across those Availability Zones. Incoming traffic is distributed equally across all Availability Zones enabled for your load balancer.

13. Which of the CloudWatch services mentioned below is NOT a part of the AWS free tier?

    • 10 alarms/month
    • 1 million API request/month
    • 10 metrics/month
    • 15 detailed monitoring metrics
    Explanation:
    CloudWatch provides the basic monitoring metrics (at five-minute frequency), 10 metrics (applica-ble to detailed monitoring for the Amazon EC2 instances or custom metrics), 10 alarms, and 1 mil-lion API requests each month at no additional charge.

14. In the context of sending metrics to CloudWatch using Amazon Kinesis, which of the following statements best describes the metric “PutRecord.Latency”?

    • It is the time taken per PutRecord operation, measured over the specified time period.
    • It is the number of successful records in a PutRecords operation per Amazon Kinesis stream, measured over the specified time period.
    • It is the time taken per PutRecords operation to calculate the statistics of the PutRecords opera-tions.
    • It is the number of successful PutRecord operations per Amazon Kinesis stream, measured over the specified time period.
    Explanation:
    The metric PutRecord.Latency measures the time taken per PutRecord operation, measured over the specified time period.
    Dimensions: StreamName
    Statistics: Minimum, Maximum, Average
    Units: Milliseconds

15. Can a user depict CloudWatch metrics such as CPU utilization in % and Network I/O in bytes on a single graph?

    • No, a user cannot graph two separate metrics on the same graph.
    • Yes, a user can graph several metrics over time on a single graph.
    • No, a user cannot plot several metrics on a single graph since the units are different.
    • Yes, a user can graph multiple metrics on the same graph provided they are of the same instance in the same AZ.
    Explanation:
    You can graph several metrics over time on the same graph. The user can select metrics across re-sources and graph them on a single graph. It is not required that they should be of the same instance. They can be of different instances with the same AMI or based on some other dimension. You can filter records and plot them all on the same graph.

16. Which of the following comes before Auto Scaling group creation?

    • Creating the Auto Scaling launch config
    • Creating the Auto Scaling policy
    • Creating the Auto Scaling tags
    • Creating the Auto Scaling instance

    Explanation:
    The Auto Scaling launch config is the first step that should be run before a user can create an Auto Scaling group. The launch config has all the information, such as the instance type, AMI ID, and other instance launch parameters. The Auto Scaling group uses this launch config to create a new group.

17. A placement group in Amazon EC2 can

    • place high memory instances in one logical group.
    • logically name and tag different tiers of the system (DB, application, business logic etc).
    • isolate any instance-type physically so that groups access local resources.
    • reduce network latency and increase network throughput
    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 per-formance for your placement group, choose an instance type that supports enhanced networking.

18. Which of the following statements is true about Auto Scaling?

    • You can only delete your Auto Scaling group but not your Auto Scaling setup.
    • If the Auto Scaling infrastructure is being deleted, it is not mandatory to delete the launch con-figuration.
    • You can only delete your Auto Scaling set up but not your Auto Scaling group.
    • If the Auto Scaling infrastructure is being deleted, it is mandatory to delete the launch configura-tion.
    Explanation:
    You can create an Auto Scaling group to maintain the healthy number of instances at all times, and optionally delete this basic Auto Scaling infrastructure. You can either delete your Auto Scaling set up or delete just your Auto Scaling group and keep your launch configuration to use at a later time.

19. If you specify only the general endpoint (autoscaling.amazonaws.com), Auto Scaling directs your request to the:

    • us-west-2 endpoint.
    • eu-central-1.
    • eu-west-1 endpoint.
    • us-east-1 endpoint.
    Explanation:
    If you just specify the general endpoint (autoscaling.amazonaws.com), Auto Scaling directs your request to the us-east-1 endpoint.

20. A user has configured ELB with Auto Scaling. The user temporarily suspended the Auto Scaling terminate process. What might the Availability Zone Rebalancing process (AZRebalance) conse-quently cause during this period?

    • Auto Scaling will keep launching instances in all AZs until the maximum instance number is reached.
    • AZ Rebalancing might now allow Auto Scaling to launch or terminate any instances.
    • AZ Rebalancing might allow the number instances in an Availability Zone to remain higher than the maximum size
    • It is not possible to suspend the terminate process while keeping the launch active.
    Explanation:
    Auto Scaling performs various processes, such as Launch, Terminate, and Availability Zone Re-balance (AZRebalance). The AZRebalance process type seeks to maintain a balanced number of in-stances across Availability Zones within a region. If the user suspends the Terminate process, the AZRebalance process can cause the Auto Scaling group to grow up to ten percent larger than the maximum size. This is because Auto Scaling allows groups to temporarily grow larger than the max-imum size during rebalancing activities. If Auto Scaling cannot terminate instances, the Auto Scal-ing group could remain up to ten percent larger than the maximum size until the user resumes the Terminate process type.