Amazon Route 53

Introduction

this post is a hub of notes of amazon route 53

Routing Policies in Amazon Route 53: Simplifying DNS Management

Routing policies in Amazon Route 53 are integral to managing DNS queries, helping determine how clients access resources. Unlike traffic routing in load balancers, routing policies in Route 53 focus on DNS-level decisions. Route 53 translates hostnames into IP addresses or endpoints, guiding clients on where to send HTTP queries without directly routing traffic.

Amazon Route 53 supports several routing policies: simple, weighted, failover, latency-based, geolocation, multi-value answer, and geoproximity. Each serves a specific purpose, with the simple routing policy being the most straightforward. The simple policy maps a domain (e.g., foo.example.com) to a single resource or multiple IP addresses. If multiple IPs are provided, clients select one randomly. This basic approach lacks health check integration but remains an efficient way to direct traffic.

By defining TTL (time-to-live) values, such as 20 seconds, you can control how long DNS responses are cached. Route 53’s flexibility also allows edits to existing records, enabling dynamic updates to IP addresses. This simplicity and efficiency make it an ideal starting point for managing DNS routing in AWS.

Latency Routing Policy will evaluate the latency between your users and AWS Regions, and help them get a DNS response that will minimize their latency (e.g. response time)

Simple Routing Policy

A simple routing policy in Amazon Route 53 is the most straightforward DNS routing strategy. It maps a domain name (e.g., example.com) to a single resource, such as an IP address or an alias for an AWS resource. If multiple IP addresses are specified, the DNS response includes all of them, and the client randomly selects one to use.

Key features of the simple routing policy include:

No Health Checks: It does not support health checks to monitor the availability of resources. Random Selection: When multiple values are provided, clients choose one at random.

Ease of Use: Ideal for straightforward DNS configurations where no additional logic or failover mechanisms are required. This policy is called “simple” because of its basic functionality and minimal configuration requirements.

weighted routing policy

Weighted Routing Policy in Amazon Route 53: Managing Traffic Distribution Main Idea: The weighted routing policy in Amazon Route 53 allows you to distribute DNS query traffic to multiple resources based on assigned weights, enabling precise control over traffic distribution.

Sub-Ideas:

How Weighted Routing Works:

Assign relative weights to DNS records. Traffic is distributed proportionally to the weights. For example, if weights are 70, 20, and 10, 70% of traffic goes to the first resource, 20% to the second, and 10% to the third. Key Features:

Weights don’t need to sum to 100; they are relative indicators. All DNS records must share the same name and type. Supports optional health checks for monitoring resources. Use Cases:

Load balancing across regions. Gradual rollout of new application versions. Traffic redirection adjustments by modifying weights. Setting a weight of 0 to stop sending traffic to a resource temporarily.