[AWS DA - Cloud Fundamentals] 2.5 Networking & Elasticity

Route 53

Route 53 is a cloud domain name system (DNS) service that has servers distributed around the globe used to translates human-readable names like www.google.com into the numeric IP addresses like 74.125.21.147.

Features

• scales automatically to manage spikes in DNS queries
• allows you to register a domain name (or manage an existing)
• routes internet traffic to the resources for your domain
• checks the health of your resources

TIps:

• Route 53 allows you to route users based on the user’s geographic location.

Elasticity in the Cloud

One of the main benefits of the cloud is that it allows you to stop guessing about capacity when you need to run your applications. Sometimes you buy too much or you don't buy enough to support the running of your applications.

With elasticity, your servers, databases, and application resources can automatically scale up or scale down based on load.

• Scale up: Vertical scaling by resizing an instance to add more capacity
• Scale out: Horizontal scaling by increasing the number of servers in the farm

EC2 Auto Scaling

EC2 Auto Scaling is a service that monitors your EC2 instances and automatically adjusts by adding or removing EC2 instances based on conditions you define in order to maintain application availability and provide peak performance to your users.

Features

• Automatically scale in and out based on needs.
• Included automatically with Amazon EC2.
• Automate how your Amazon EC2 instances are managed.

Tips:

• EC2 Auto Scaling is found on the EC2 Dashboard.
• You can know when Ec2 Auto scaling is launching or terminating in instance by SNS
• EC2 Auto Scaling adds instances only when needed, optimizing cost savings.
• EC2 predictive scaling removes the need for manual adjustment of auto scaling parameters over time.

EC2 - Create Auto Scaling group

EC2 - Auto Scaling Group

Elastic Load Balancing

Elastic Load Balancing automatically distributes incoming application traffic across multiple servers.

Elastic Load Balancer is a service that:

• Balances load between two or more servers
• Stands in front of a web server
• Provides redundancy and performance

Redundancy: 

If you lose a server, the load balancer will send requests to other working servers. This feature maintains continueous operations in an emergency.

Performance: 

If a server starts having issues or bottlenecks, the load balanecr will add more servers to the pool of aailable servers.

Auto scaling automatically adjusts capacity to maintain a steady state.

Tips:

• Elastic Load Balancing works with EC2 Instances, containers, IP addresses, and Lambda functions
• You can configure Amazon EC2 instances to only accept traffic from a load balancer.