EC2 and Storage Flashcards
This is based on Section 5, 6 and 7
What is the point of EC2 Instance Roles?
They allow for the instance to perform API calls on behalf of the instance to other AWS resources (i.e. Calls to IAM or S3)
What is the difference between the On-Demand and Reserved Instance options?
On-Demand has no up-front costs, and is payed for by the second. You have full control over its lifecycle.
Reserved Instances are physically the same as On-Demand, however a billing discount is applied and must have certain attributes applied.
What are Spot Fleets?
Spot fleets are a set of Spot Instances + (optional) On-Demand instances that are managed by AWS. The Spot Fleet will try to meet the target capacity with price constraints.
We must define multiple launch pools.
What is a storage optimized Instance?
Instances designed for workloads that require high, sequential read and write access to very large data sets.
What are the three Placement Group strategies?
Cluster: Clusters instances into a low-latency group in a single AZ, same hardware, low-latency
Spread: Spreads instances across underlying hardware
Partition: Spreads instances across many different partitions within an AZ, such that groups in one partition do not share underlying hardware with groups of instances in another partition
What is the max number of Partitions you can have per AZ for a Placement Group partition strategy?
Seven
Why would you create your own ENIs?
When instances are deleted, the default ENIs are deleted with them. With the creation of our own ENIs, we get to move them to instances we need them to be attached to and assign certain IP Addresses.
What is a Spot Instance?
Spot instances are instances that are ran when capacity is available and the spot price is lower than our maximum rates.
You have an application performing big data analysis hosted on a fleet of EC2 instances. You want to ensure your EC2 instances have the highest networking performance while communicating with each other. Which EC2 Placement Group should you choose?
Cluster Placement
You have a critical application hosted on a fleet of EC2 instances in which you want to achieve maximum availability when there’s an AZ failure. Which EC2 Placement Group should you choose?
Spread
Why would you use a Partition Placement strategy?
This is a good balance between High Performance and High Availability; we can have multiple instances in the same rack for High Performance and instances in other racks for High Availability.
True or False: Elastic Network Interface (ENI) can be attached to EC2 instances in another AZ.
False. ENIs are bounded to a specific AZ
What storage type must be used to enable EC2 Hibernate?
EBS. The data persisting in RAM is migrated to EBS when the instance is hibernated. Only works with GP and Provisioned IOPS
How does EBS attach to an Instance?
Through a network drive. This allows us to attach and detach
True or False: EBS can be bound across AZs?
False. If we want to move it across AZs, we need to create a snapshot and recreate it in another AZ
If we want to move EBS volume across an AZ or Region, what can we do?
Create an EBS snapshot
What is an AMI?
Amazon Machine Image. It provides the information needed to launch an Instance.