MegaQuiz Flashcards
You have a high performance compute application and you need to minimize network latency between EC2 instances as much as possible. What can you do to achieve this?
Create a placement group and place the EC2 instances in the group.
Placement Groups can be created across 2 or more Availability Zones.
False
Which of the services below do you get root access to?
EC2 AND Elastic MapReduce.
When you create new subnets within a custom VPC, by default they can communicate with each other, across availability zones.
True
It is possible to transfer a reserved instance from one Availability Zone to another.
True
You have an EC2 instance which needs to find out both its private IP address and its public IP address. To do this you need to?
Retrieve the instance metadata from:
http://169.254.169.254/latest/meta-data/
Amazon S3 buckets in all regions provide read-after-write consistency for PUTS of new objects.
True
Amazon S3 buckets in all regions do not provide eventual consistency for overwrite PUTS and DELETES.
False
In order to enable encryption at rest using EC2 and Elastic Block Store you need to
Configure encryption when creating the EBS volume
Amazon’s Redshift uses which block size for its columnar storage?
1024KB / 1MB
You run a website which hosts videos and you have two types of members, premium fee paying members and free members. All videos uploaded by both your premium members and free members are processed by a fleet of EC2 instances which will poll SQS as videos are uploaded.
However you need to ensure that your premium fee paying members videos have a higher priority than your free members. How do you design SQS?
Incorrect, SQS does not set priorities on individual items.
It would be best to create two queues and have the EC2 fleet poll the premium queue first and if empty, then poll your free members SQS queue. .
You have been asked to create VPC for your company. The VPC must support both Internet-facing web applications (ie they need to be publicly accessible) and internal private applications (i.e. they are not publicly accessible and can be accessed only over VPN). The internal private applications must be inside a private subnet. Both the internet-facing and private applications must be able to leverage at least three Availability Zones for high availability. At a minimum, how many subnets must you create within your VPC to achieve this?
minimum 6
You work for a cosmetic company which has their production website on AWS. The site itself is in a two-tier configuration with web servers in the front end and database servers at the back end. The site uses using Elastic Load Balancing and Auto Scaling. The databases maintain consistency by replicating changes to each other as and when they occur. This requires the databases to have extremely low latency. Your website needs to be highly redundant and must be designed so that if one availability zone goes offline and Auto Scaling cannot launch new instances in the remaining Availability Zones the site will not go offline. How can the current architecture be enhanced to ensure this?
In this scenario.
- You need high low latency - so no cross region replication is an option.
- If you lost an availability zone, you would still have 2 other Availability Zones available each that is configured to handle 50% peak load per zone. 50% + 50% = 100%.
So your site in three different AZs.
- same region
- configure auto scaling to handle 50% of the peak load.
You are a systems administrator and you need to monitor the health of your production environment. You decide to do this using Cloud Watch, however you notice that you cannot see the health of every important metric in the default dash board. Which of the following metrics do you need to design a custom cloud watch metric for, when monitoring the health of your EC2 instances?
None Custom:
* CPU + Disk IO + network Ingress
Custom Cloud:
Memory Usage
You work for a toy company that has a busy online store. As you are approaching Christmas, you find that your store is getting more and more traffic. Your web tier is behind an Auto Scaling group, but you notice that is is frequently scaling, sometimes multiple times in an hour, only to scale back down after peak usage. You need to keep Auto Scaling from scaling up and down so rapidly. What would help achieve this ?
1) Modify the Auto scaling group cool down triggers.
2) Modify the amazon cloudwatch alarm period that triggers your auto scaling down policy.
You work in the genomics industry and you process large amounts of genomic data using a nightly Elastic Map Reduce (EMR) job. This job processes a single 3 Tb file which is stored on S3. The EMR job runs on 3 on-demand core nodes and four on-demand task nodes. The EMR job is now taking longer than anticipated and you have been asked to advise how to reduced the completion time?
- Using an equal number of spot instances would not reduce the EMR time.
Reduce the the input split size in the MapReduce job configuration and then adjust the number of simultaneous mapper tasks so that more tasks can be processed at once.
You have been asked to identify a service on AWS that is a durable key value store. Which Service best meets this definition?
Simple Storage Service (S3)
You are a solutions architect working for a biotech company who is pioneering research in immunotherapy. They have developed a new cancer treatment that may be able to cure up to 94% of cancers. They store their research data on S3, however recently an intern accidentally deleted some critical files. You’ve been asked to prevent this from happening in the future. What options below can prevent this?
1) Enable S3 Versioning.
2) Enable 2 FA
By enabling versioning’s MFA Delete capability, which uses multi-factor authentication, can be used to provide an additional layer of security.
Your company has decided to set up a new AWS account for test and dev purposes. They already use AWS for production, but would like a new account dedicated for test and dev so as to not accidentally break the production environment. You launch an exact replica of your production environment using a cloudformation template that your company uses in production. However cloudformation fails. You use the exact same CloudFormation template in production so the failure is something to do with your new AWS account. The CloudFormation template is trying to launch 60 new EC2 instances in a single availability zone. After some research you discover that the problem is;
There is a soft limit of 20 instances per region. Submit the limit increase form and retry the failed requests once approved (as per http://aws.amazon.com/ec2/faqs/)
You work for a famous bakery who are deploying a hybrid cloud approach. Their legacy IBM AS400 servers will remain on premise within their own datacenter however they will need to be able to communicate to the AWS environment over a site to site VPN connection.
What do you need to do to establish the VPN connection?
Assign a public IP Address to your Amazon VPC gateway. You don’t need an AWS direct connect to establish a VPN Connection)
What is an AWS placement group?
Placement Groups are logical groupings or clusters of instances in the selected AWS region. Placement groups are specifically used for launching cluster compute instance types.
Placement Groups are restricted to a single Availability Zone.
You work for a automotive company which is migrating their production environment in to AWS. The company has 4 separate segments, Dev, Test, UAT & Production. They require each segment to be logically isolated from each other. What VPC configuration should you recommend?
The best answer is to deploy a separate VPC for each segment, completely isolating that segment from the other segments.
By default how many VPCs can you have per region in your AWS account?
5
Which of the following is true when writing to S3?
S3:
- Ready-After-Write consistency for puts of new objects.
- eventual consistency for overwrites PUTS and DELETES
Which services do you get OS level access to?
EC2 and Elastic Map Reduce (EMR)
You are designing an AWS solution for a new customer and they want to use their active directory credentials in order to sign in to the AWS management console. What kind of authentication response is required in order for users to authenticate with the AWS security token service (STS).
SAML2.0
You are creating a new VPC with 3 subnets in 3 separate availability zones. You require instances in each subnet to be able to communicate to each other by default. What additional step should you take in order to achieve this objective?
By default all subnets will be able to communicate with each other using the main route table.
You are an AWS architect and you require encryption at rest for additional volumes attached to your EC2 instance. What is the quickest and most efficient way to achieve this?
Configure Encryption when creating the EBS volume. You could use the OS to encrypt the volume after mounting it as an Ec2 instance, however, that is not the quickest or most efficient way.
You are designing a web application for a new social media start up and have recommended using DynamoDB for the database due to its superior performance. You need to ensure that your database has redundancy. What additional steps should you do?
Dynamo DB is automatically redundant across multiple availability zones.
What blocksize does Redshift use when storing it’s data in columnar storage?
1024kb
You have been monitoring a sensitive autoscaling group, and you expect it to scale-in as you enter a period of holiday downtime. The auto scaling group is distributed over three AZs ( AZ - A & -B have two instances each, and AZ -C has three instances). All instances have different CPU and Memory utilization, and all instances have been running for a different number of days. All instances come from different versions of a root AMI, and all instances have different numbers of sessions connected. Which instance will be the 1st to shut down?
The instance in AZ -C that has the oldest launch configuration.
Auto Scaling is a tool used to create fault-tolerant and cost-effective architectures. True / False
True.
Auto-scaling improves availability and will keep your infrastructure at the size needed to run your application
What is the maximum VisibilityTimeout of an SQS message in a FIFO queue?
12 hours.
The visibility timeout controls how long a message is invisible in the queue while it is being worked on by a processing instance. This interval should not be confused with how long the message can remain in the queue.
A client who is using EC2 believes that someone other than approved administrators is trying to gain access to her Linux web app instances, and she asks what sort of network access logging can be added to the system. What would you recommend?
You should make use of an OS level logging tools such as iptables and log events to CloudWatch or S3.
Your company likes the idea of storing files on AWS. However, low-latency service of the last few days of files is important to customer service. Which Storage Gateway configuration would you use to achieve both of these ends?
Gateway-Cached volumes retain a copy of frequently accessed data subsets locally. Cached volumes offer a substantial cost savings on primary storage and minimize the need to scale your storage on-premises.
You have a MySQL database running on an EC2 instance in a private subnet. You can connect via SSH, but you are unable to apply updates to the database server via the NAT instance. What might you do to remedy this problem?
With NAT instances, the most common oversight is forgetting to disable Source/Destination Checks.
When editing permissions (policies and ACLs), to whom does the concept of the “Owner” refer?
The “Owner” refers to the identity and email address used to create the account AWS account.
