Elastic Compute Cloud Flashcards
What is EC2?
Elastic Compute Cloud
EC2 is an example of ___ as a Service?
Infrastructure
What 4 main things make up EC2?
- Renting virtual machines (EC2)
- Storing data on virtual drives (EBS)
- Distributing load across machines (ELB)
- Scaling the services using an auto-scaling group (ASG)
What EC2 sizing and configuration options are there?
- Operating System: Linux, Windows, Mac
- How much compute power and cors (CPU)
- How much random-access memory (RAM)
- How much storage space: Network-attached (EBS & EFS) / hardware (EC2 Instance Store)
- Network card: speed of the card, Public IP address
- Firewall rules: security group
- Bootstrap script (configure at first launch): EC2 User Data
What is EC2 User Data script?
Used to bootstrap our instances. Runs only once at the instance first start
What user does the EC2 User Data Script run with?
Root user
What does AMI stand for?
Amazon Machine Image
What is an Amazon Machine Image?
A template that contains the software configuration required to launch your instance.
What are the 7 EC2 instance types?
- General Purpose
- Compute Optimized
- Memory Optimized
- Accelerated Computing
- Storage Optimized
- Instance Features
- Measuring Instance Performance
Break down the naming convention of m5.2xlarge
m: instance class
5: generation (AWS improves them over time)
2xlarge: size within the instance class
What is EC2 General Purpose Instance Type?
Great for a diversity of workloads such as web servers or code repositories. Balance between compute, memory, networking
What is EC2 Compute Optimized Instance Type?
Great for compute-intensive tasks that require high performance processors. Ex: machine learning and dedicated gaming servers.
What is EC2 Memory Optimized Instance Type?
Fast performance for workloads that process large data sets in memory. Ex: high performance databases.
What is EC2 Storage Optimized Instance Type?
Great for storage-intensive tasks that require high, sequential read and write access to large data sets on local storage. Ex: relational & NoSQL databases, data warehousing applications
What are security groups?
The fundamental of network security in AWS. They control how traffic is allowed into or out of our EC2 instances. They only contain allow rules and can reference by IP or by security group. The firewall.
What do security groups regulate?
- Access to Ports
- Authorized IP ranges - IPv4 and IPv6
- Control of inbound network (from other to the instance)
- Control of outbound network (from the instance to other)
Can an instance have multiple security groups attatched?
Yes
Can a security group be attached to multiple instances?
Yes
Are security groups locked down to a region / VPC combination?
Yes
If traffic is blocked by a security group, will the EC2 instance see it
No
Is it good to maintain one separate security group for SSH access?
Yes
Is it a security group issue if your application is not accessible (time out)
Yes
Is it a security group issue if your application gives a ‘connection refused’ error
No, it’s is an application error or it’s not launched
All inbound traffic is ___ by default
blocked
All outbound traffic is ___ by default
authorized
What is port 22 for?
SSH (Secure Shell) - log into a Linux instance
What is port 21 for?
FTP (File Transport Protocol) - upload files into a file share
What is port 22 for?
SFTP (Secure File Transport Protocol) - upload files using SSH