EC2 Flashcards
What are the main features/services of EC2?
- Renting virtual machines (EC2)
- Storing Data on virtual drives (ELB)
- Scaling the services using an auto-scaling group
What are the configuration options for a virtual machine?
- OS
- CPU
- RAM
- Storage (EBS, EFS, Instance Storage?
- Network card
- security group
How can an EC2 machine be configured automatically?
-Through a bootstrap script at launch
Which special types exist for EC2?
- General Purpose
- Compute Optimized
- Memory Optimized
- Storage Optimized
How can you control traffic to/from EC2 Instances
Through Security Groups
What do security groups control?
- Access to ports
- Authorised IP ranges -IPv4 and IPv6
- Control of inbound network
- Control of outbound network
What are the default traffic rules for security groups?
- All inbound traffic is blocked
- All outbund traffic is allowed
Which purchasing option do you choose for long term planned workloads?
Reserved Instances
Which purchasing option do you choose for cheap, short workloads that can be interrupted?
Spot Instances
What are dedicated instances?
No other customer will share the hardware
What are dediacted hosts?
You can book an entire physical server and control instance placement.
Which purchasing option do you choose for short workloads that can not be interrupted?
On demand instances
What are dedicated hosts used for?
It is ued to fullfill compliance when licenses are bound to hardware.
What is an Elastic IP?
An Elastic IP is a public static IPv4 IP that can be attached to an EC2 instance
Why avoid Elastic IPs?
They are often a sign for architectural decisions?
How to avoid Elastic IPs?
register a DNS to a random public IP
-use a Load Balancer
What are the available EC2 placement groups?
- Cluster
- Spread
- Partition
You have a very critical application. Which EC2 placement group do you need and why?
- spread
- EC2 instances are on different physical hardware
- instances can spread multiüle availability zones
You have a big data job that needs to conmplete fast. Which placement group to use and why?
- cluster
- instances are in the same rack and connected via very low latency and high speed network
What are elastic network interfaces?
They are virtual network cards that can be attached to EC2 instances
What is EC2 Hibernate and how does it work?
The RAM of an EC2 instance is written to an EBS storage and written back to RAM on reboot
What is a vCPU?
A cpu thread.
What is an EBS volume?
a network drive that can be attached to an ec2 instance
How are you billed for an EBS volume?
- size in GBs
- IOPS
How can EBS be backuped?
You create snapshots in s3
How can you standardize your EC2 configurations quickly at launch?
Through AMIs (Amazon Machine Images).
What if an EBS has too high latency?
Use EC2 Instance Store (Machine integrated storage)
Are EBS volumes encrypted?
Yes.
How can EBS fault tolerance be improved?
By combining 2 or more volumes in a RAID0 or RAID1 array
What is efs?
Elastic file system is a network file system that can be mounted to multiple ec2 instances across multiple availability zones. It can scale dynamically.
When to use ebs vs efs?
EBS: low-latency interactive applications that require consistent, predictable performance
EFS: used for storing large amounts of data that needs to be accessed fast and can not be stored on one EBS volume on one ec2 instance
