Amazon EC2 Overview

Amazon Elastic Compute Cloud (EC2) instances are virtual computers on cloud, on which you can install and run applications. 

EC2 has very flexible pricing policies. We can launch servers with applications when needed without upfront commitments, thus eliminating the need to invest in hardware up front and reducing need to forecast. There are also options to reserve servers and get discounts and guarantee.

EC2 allow you to you to quickly scale capacity, both up and down (horizontal scaling), as your computing requirements change. EC2 also support auto scaling based on various criteria that can be configured.

EC2 provides a range of servers starting from low load servers to high load cluster servers. 

Important EC2 Terms and Concepts

1. Instance types

   • Various configurations of CPU, memory, storage, and networking capacity for the EC2 instances. Read more here.

2.  Amazon Machine Images (AMIs)

   • These are preconfigured templates for your instances ((including the operating system and additional software). There are Amazon provided as well as community AMIs. You can filter AMIs based on Operating system, Architecture and Root device types.

3. Instance store volumes

   • Storage volumes for temporary data. Gets deleted when you stop or terminate your instance.

4. Amazon EBS volumes

   • Persistent storage volumes for your data using Amazon Elastic Block Store (Amazon EBS). Read more here.

5. Availability Zones

   • Multiple physical locations for your resources (e.g. instances, EBS volumes) within a region for high availability and reliability.

6. Elastic IP addresses

   • Static IPv4 addresses for dynamic cloud computing. Free when in use, but charged if kept unused in our pool.

7. Tags

   • Metadata that you can create and assign to your Amazon EC2 resources. Help you manage your instances, images, and other Amazon EC2 resources, as they help you find where the costs are coming from.

8. Virtual private clouds (VPCs)

   • Virtual networks you can create that are logically isolated from the rest of the AWS cloud.

9. Amazon EC2 API Actions

   • Amazon EC2 provides a Query API that accept HTTP or HTTPS requests with verbs GET or POST and a Query parameter named Action.

   • Actions include AcceptReservedInstancesExchangeQuote, AcceptVpcPeeringConnection, AllocateAddress etc. Read more here. 

10. Security & Firewall

    • AWS secure login information for your instances using key pairs (AWS stores the public key, and you store the private key in a secure place).

    • AWS provides a firewall that enables you to specify the protocols, ports, and source IP ranges that can reach your instances using security groups.