[AWS] Auto Scaling

Here is the confusing part. AWS provides multiple auto scaling services: notably ASW Auto Scaling and EC2 Auto Scaling.

  • AWS Auto Scaling lets you configure and manage scaling for your scalable AWS resources through a scaling plan.
  • EC2 Auto Scaling is an AWS service that automatically increases or decreases the number of on-demand instances based on chosen CloudWatch metrics.
Continue reading “[AWS] Auto Scaling”

[AWS] Load Balancing

Load balancing is a method used to distribute incoming connections across a group of servers or services.

  • Elastic Load Balancing (ELB) automates distributing traffic evenly to all instances in multiple AZs within a region.
    • Cross Zone Load Balancing allows load balancers to cross multiple AZs.
  • SSL can be directly applied to ELB – can help reduce the compute power on an EC2 instance.
Continue reading “[AWS] Load Balancing”

[AWS] CloudFront

Cloud Front is a Content Delivery Network (CDN) – lower latency, higher transfer speed, and reduced server load. It has built-in DDoS (distributed denial of service) attack protection.

  • CloudFront is a global service.
  • The domain name is created when a distribution is created and is used to view contents in a browser.
  • Objects are cached for the life of the Time to Live (TTL). – 24 hours by default
  • You can invalidate (clear) cached contents manually with some costs.
  • You can use CloudFront Groups (the primary origin and the second origin) for origin failover.
Continue reading “[AWS] CloudFront”


Domain Name System (DNS)

DNS is a process of mapping a human-friendly domain name to an IP address.

  • DNS Root Servers: A group of servers to answer the root zone. Top Level Domains (TLDs) are controlled by the root zone database – Internet Assigned Numbers Authority (IANA).
  • Domain Registrars: All domain names must be unique. A registrar is an authority that can assign domain names to top-level domains and ensure its uniqueness. Each domain name becomes registered in a central database (WhoIS server).
Continue reading “[AWS] DNS”