EC2 Section

Question 1

EC2

Answer 1

• EC2 = Elastic Compute Cloud = Infrastructure as a Service

It mainly consists in the capability of :
• Renting virtual machines (EC2)
• Storing data on virtual drives (EBS)
• Distributing load across machines (ELB)
• Scaling the services using an auto-scaling group (ASG)

Question 2

EC2 User Data

Answer 2

• It is possible to bootstrap our instances using an EC2 User data script.
• That script is only run once at the instance first start
• EC2 user data is used to automate boot tasks

Question 3

EC2 Naming Convention

Answer 3

m5.2xlarge

• m: instance class
• 5: generation (AWS improves them over time)
• 2xlarge: size within the instance class

Question 4

EC2 Instance Types – General Purpose

Answer 4

• for web servers or code repositories

Balance between:
• Compute
• Memory
• Networking

Question 5

EC2 Instance Types – Compute Optimized

Answer 5

compute-intensive tasks that require high performance processors:
• Batch processing workloads
• Media transcoding
• High performance web servers
• High performance computing (HPC)
• Scientific modeling & machine learning
• Dedicated gaming servers

Question 6

EC2 Instance Types – Memory Optimized

Answer 6

• Fast performance for workloads that process large data sets in memory

Use cases:
• High performance, relational/non-relational databases
• Distributed web scale cache stores
• In-memory databases optimized for BI (business intelligence)
• Applications performing real-time processing of big unstructured data

Question 7

EC2 Instance Types – Storage Optimized

Answer 7

• Great for storage-intensive tasks that require high, sequential read and write
access to large data sets on local storage

Use cases:
• High frequency online transaction processing (OLTP) systems
• Relational & NoSQL databases
• Cache for in-memory databases (for example, Redis)
• Data warehousing applications
• Distributed file systems

Question 8

Security Groups

Answer 8

• They control how traffic is allowed into or out of our EC2 Instances (firewall)
• Locked to a region/VPC but can be attached to multiple instances
• only contain allow rules
• rules can reference by IP or by security group
• All inbound traffic is blocked by default
• All outbound traffic is authorised by default

They regulate:
• Access to Ports
• Authorised IP ranges – IPv4 and IPv6
• Control of inbound network (from other to the instance)
• Control of outbound network (from the instance to other)

Question 9

Ports to know

Answer 9

• 22 = SSH (Secure Shell) - log into a Linux instance
• 21 = FTP (File Transfer Protocol) – upload files into a file share
• 22 = SFTP (Secure File Transfer Protocol) – upload files using SSH
• 80 = HTTP – access unsecured websites
• 443 = HTTPS – access secured websites
• 3389 = RDP (Remote Desktop Protocol) – log into a Windows instance

Question 10

SSH

Answer 10

• allows you to control a remote machine, all using the command line

Question 11

EC2 Instance Connect

Answer 11

• Connect to your EC2 instance within your browser
• No need to use your key file that was downloaded
• The “magic” is that a temporary key is uploaded onto EC2 by AWS
• Works only out-of-the-box with Amazon Linux 2
• Need to make sure the port 22 is still opened

Question 12

EC2 On Demand

Answer 12

Pay for what you use:
• Linux or Windows - billing per second, after the first minute
• All other operating systems - billing per hour

• Has the highest cost but no upfront payment
• No long-term commitment
• Recommended for short-term and un-interrupted workloads

Question 13

EC2 Reserved Instances

Answer 13

• Up to 72% discount compared to On-demand
• Reservation period: 1 year = + discount | 3 years = +++ discount
• Reserve a specific instance type

Convertible Reserved Instance
• can change the EC2 instance type
• Up to 45% discount

Scheduled Reserved Instances
• launch within time window you reserve
• When you require a fraction of day / week / month
• Commitment for 1 year only

Question 14

EC2 Spot Instances

Answer 14

• Can get a discount of up to 90% compared to On-demand
• Instances that you can “lose” at any point of time if your max price is less than the current spot price
• The MOST cost-efficient instances in AWS
• Useful for workloads that are resilient to failure

Question 15

EC2 Dedicated Hosts

Answer 15

• physical server with EC2 instance capacity fully dedicated to your use. can help you address compliance requirements and reduce costs by allowing you to use your existing server-bound software licenses.
• Allocated for your account for a 3-year period reservation