AWS Gen Study Flashcards
How does the credentials file play a role in the AWS CLI?
When running a CLI command that does not explicitly specify which profile to use, it will look to the credentials file;
What is the AWS CLI credentials chain?
Command line options; Environment variables; CLI Credentials file; Configuration file; Container Credentials; Instance profile credentials;
You can point an Alias to an unlimited number of function versions, true or false?
False. You can point it to two.
What is lazy loading in Amazon ElastiCache?
When data is requested, it looks in the cache to see if it exists; if it doesn’t it will grab it from the DB, and then write it to the cache
What are the disadvantages of a write-through in ElastiCache?
Missing data - when you spin up a new node, there is missing data; the data is missing until its updated or added to the DB;
Cache churn - most data will sit there and not be read (we can fix this with TTL);
What is an CodeDeploy deployment group?
It is a CodeDeploy entity for grouping EC2 instances or AWS Lambda functions in a CodeDeploy Deployment
To control access to an API in API Gateway, we can configure the security group of the API, true or false?
False. API Gateway does not use security groups but uses resource policies
Auto Scaling Group can span regions, true or false?
False. they can span AZs
Auto Scaling Groups can work with both Network and Application Load Balancers, true or false?
True
What API operation can we use to get security credentials to an existing IAM user? What parameter can we use to specify timing?
GetSessionToken and Duration Seconds
How can we request temporary security credentials?
With AWS STS
What is the AssumeRole API operation used for?
It is useful for allowing existing IAM users to access AWS resources they don’t already have access to. It can also be used cross-account
What file is used by CodeDeploy to manage the deployment?
appspec.yaml
What are the Elastic Beanstalk deployment options?
All At Once Rolling Rolling with additional batch Immutable update Traffic Splitting
What are negatives about Elastic Beanstalk Immutable update?
It is the highest cost and longest deployment but zero downtime
We need to decrypt files with KMS. How can we do this?
We take an encrypted key and pass it to the decrypt operation. We then use the plain text key to decrypt the encrypted file. Remove the plain text key from memory as soon as possible
What is the difference between a delay queue and a visibility timeout for SQS?
A delay queue is a period of time where the item added to the queue cannot be consumed once it has been added to the queue. The visibility timeout only is applicable once a message has been consumed.
To implement long polling, we hit the SetQueueAttributes with a WaitTimeSeconds parameter. True or False?
False. SetQueueAttributes can be used to set things about the Queue like DelaySeconds and VisibilityTimeout. We want the RecieveMessage API with WaitTimeSeconds.
We can however set RevieveMessageWaitTimeSeconds on the queues parameters.
How do we Recieve Messages in SQS?
We hit the RevieveMessages API and can consume one to 10 messages. If you set a value greater than zero for ReceiveMessageWaitTimeSeconds, than long polling is in effect. This will also query all servers instead of a subset of servers.
We want to notify someone when items are uploaded to an S3 bucket. What is the best way to achieve this?
Add an event on the bucket to send out a PUT or POST to SNS
We want to update our current instances with no downtime in elastic beanstalk and using the existing instances; what is a good option?
Rolling with additional batches. The new batch will receive requests while the old instances are update. Then, when all the old batches are updated, the new batch will be terminated.
In standard rolling update, instances taken out in batches cannot serve requests
When using an on-premise server, you should attatch an IAM role and use that to make API calls to AWS, true or false?
False. You cannot attatch an IAM role to an on-premise server. You should create an IAM user, generate access keys and create a credentials file on the on-premise server. If it was an EC2 server, storing an IAM role would be the preferred way.