AWS Certified Solutions Architect - Associate

Question 1

SHARDS

Answer 1

Think Kinesis Streams. It is the only form of Kinesis that uses shards.
Default is storage in shards for 24hrs. Can be configured up to days

Question 2

Kinesis Firehose

Answer 2

NO PERSISTENT STORAGE (like streams>shards). Data has to be analysed as it comes in.
Can use lambda functions. Data comes in, triggers lambda then outputs to s3 or Redshift (although not directly to Redshift. Needs to go to s3 first then import in to Redshift) or Elasticsearch cluster and Splunk

Question 3

SQS - FIFO Queue

Answer 3

First-in First-Out Delivery
Exactly Once Processing
Limited to 300 transactions per second

Question 4

SQS

Answer 4

Is PULL based (not pushed = SNS)
Messages are 256KB in size
Messages can be kept in the queue from 1 minute to 14 days
Default retention is 4 days Important to remember

Question 5

SQS - Visibility Time Out

Answer 5

The amount of time that a msg is invisible in the Q after a reader picks up that msg.
DEFAULT 30 seconds
MAXIMUM is 12HRS
Provided the job is processed before the visibility timeout expires, the msg will then be deleted from the Q.
If not processed in time. The msg will become visible again and another reader will process it.
This CAN result in the same msg being delivered twice/

Question 6

SQS Polling

Answer 6

SHORT POLLING - returns immediately even if Q is empty
LONG POLLING (Saves Money) - doesn't return a response until a  message arrive sin the Q or the long poll times out.

Question 7

SWF (if TASK is mentioned think SWF)

Answer 7

Workflow executions can last up to 1 year
SWF presents a task-oriented API (whereas SQS offers a msg oriented API)
SWF ensures a task is assigned only once and never duplicated
SWF keeps track of all tasks/events in an app (For SQS you need to implement your own tracking)

Question 8

SWF

• WORKFLOW STARTERS
• DECIDERS
• ACTIVITY WORKERS

Answer 8

Workflow Starters - an app that can initiate a workflow. Could be an e-commerce website following the placement of an order, or a mobile app searching for bus times

DECIDERS - control the flow of activity tasks in a workflow execution. If something has finished/failed in a workflow, a decider decides what to do next.

ACTIVITY WORKERS - carry out the activity tasks

Question 9

SNS vs SQS

Answer 9

Both are messaging systems
SNS - Push
SQS - Polls (Pulls)

Question 10

Cross-origin resource sharing (CORS)

Answer 10

a mechanism that allows restricted resources (e.g. fonts) on a web page to be requested from another domain outside the domain from which the first resource was served.
CORS is enforced by the client.

Question 11

EXAM Q - If you see something along the lines of “Origin policy cannot be read at the remote resource”

Answer 11

You need to ENABLE CORS on API Gateway

Question 12

Attaching a network interface to an EC2 instance

Answer 12

You can attach a network interface to an EC2 instance in the following ways:

1. When it's running (hot attach)
2. When it's stopped (warm attach)
3. When the instance is being launched (cold attach).

Question 13

IAM database authentication

Answer 13

IAM database authentication is only supported in MySQL and PostgreSQL database engines.

Question 14

AWS X-Ray

Answer 14

usedto trace and analyze user requests as they travel through your Amazon API Gateway APIs to the underlying services.

Question 15

Glacier Select

Answer 15

is not a storage service.It is primarily used to run queries directly on data stored in Amazon Glacier, retrieving only the data you need out of your archives to use for analytics.

Question 16

AWS Glue

Answer 16

is a fully managed extract, transform, and load (ETL) service that makes it easy for customers to prepare and load their data for analytics.

Question 17

AWS OpsWorks

Answer 17

is a configuration management service that provides managed instances of Chef and Puppet. Chef and Puppet are automation platforms that allow you to use code to automate the configurations of your servers. OpsWorks lets you use Chef and Puppet to automate how servers are configured, deployed, and managed across your Amazon EC2 instances or on-premises compute environments.

Question 18

AWS Trusted Advisor

Answer 18

analyzes your AWS environment and provides best practice recommendations in these five categories:
Cost Optimization,
Performance,
Fault Tolerance,
Security,
andService Limits.
You can use a mnemonic, such as CPFSS, to memorize these five categories.

Question 19

Gateway endpoint

Answer 19

for Amazon S3 and DynamoDB service, you have to create a gateway endpoint and then use an interface endpoint for other services.

Question 20

How will I be charged if my Spot instance is interrupted?

Answer 20

If your Spot instance is terminated or stopped by Amazon EC2 in the first instance hour, you will not be charged for that usage. However, if you terminate the instance yourself, you will be charged to the nearest second. If the Spot instance is terminated or stopped by Amazon EC2 in any subsequent hour,you will be charged for your usage to the nearest second. If you are running on Windows and you terminate the instance yourself, you will be charged for an entire hour.

Question 21

Amazon S3 notification feature

Answer 21

Amazon S3 supports the following destinations where it can publish events:

Amazon Simple Notification Service (Amazon SNS) topic -A web service that coordinates and manages the delivery or sending of messages to subscribing endpoints or clients.

Amazon Simple Queue Service (Amazon SQS) queue -Offers reliable and scalable hosted queues for storing messages as they travel between computer.

AWS Lambda -AWS Lambda is a compute service where you can upload your code and the service can run the code on your behalf using the AWS infrastructure. You package up and upload your custom code to AWS Lambda when you create a Lambda function.

Question 22

Data pipeline

Answer 22

is primarily used as a cloud-based data workflow service that helps you process and move data between different AWS services and on-premises data sources. It is not suitable for collecting data from distributed sources such as users, IoT devices, or clickstreams.

Question 23

Amazon Redshift Spectrum

Answer 23

is a feature of Amazon Redshift that enables you to run queries against exabytes of unstructured data in Amazon S3 with no loading or ETL required.

Question 24

Snowball vs Snowball Edge

Answer 24

Although an AWS Snowball device costs less than AWS Snowball Edge, it cannot store 80 TB of data in one device. Take note that the storage capacity is different from the usable capacity for Snowball and Snowball Edge. Remember that an 80 TB Snowball appliance and 100 TB Snowball Edge appliance only have 72 TB and 83 TB of usable capacity respectively. Hence, it would be costly if you use two Snowball devices compared to using just oneAWS Snowball Edge device.

Question 25

DynamoDB auto scaling

Answer 25

uses the AWS Application Auto Scaling service to dynamically adjust provisioned throughput capacity on your behalf, in response to actual traffic patterns. This enables a table or a global secondary index to increase its provisioned read and write capacity to handle sudden increases in traffic, without throttling. When the workload decreases, Application Auto Scaling decreases the throughput so that you don’t pay for unused provisioned capacity.

Question 26

Amazon Redshift Enhanced VPC Routing

Answer 26

When you use Amazon Redshift Enhanced VPC Routing, Amazon Redshift forces all COPY and UNLOAD traffic between your cluster and your data repositories through your Amazon VPC. By using Enhanced VPC Routing, you can use standard VPC features, such as VPC security groups, network access control lists (ACLs), VPC endpoints, VPC endpoint policies, internet gateways, and Domain Name System (DNS) servers.

Question 27

Redshift Spectrum

Answer 27

is primarily used to run queries against exabytes of unstructured data in Amazon S3, with no loading or ETL required.

Question 28

Amazon EMR

Answer 28

provides you a managed Hadoop framework that makes it easy, fast, and cost-effective to process vast amounts of data across dynamically scalable Amazon EC2 instances. You CAN ACCESS the operating system of these EC2 instances that were created by Amazon EMR.

Question 29

AWS Step Functions

Answer 29

provides serverless orchestration for modern applications. Orchestration centrally manages a workflow by breaking it into multiple steps, adding flow logic, and tracking the inputs and outputs between the steps. As your applications execute, Step Functions maintains application state, tracking exactly which workflow step your application is in, and stores an event log of data that is passed between application components. That means that if networks fail or components hang, your application can pick up right where it left off.

SWF does not provide serverless orchestration to multiple AWS resources

Question 30

CloudTrail

Answer 30

By default, CloudTrail event log files are encrypted using Amazon S3 server-side encryption (SSE). You can also choose to encrypt your log files with an AWS Key Management Service (AWS KMS) key. You can store your log files in your bucket for as long as you want. You can also define Amazon S3 lifecycle rules to archive or delete log files automatically. If you want notifications about log file delivery and validation, you can set up Amazon SNS notifications.