What is [AWS] Route53? It is a DNS routing service.

Route53 is a DNS service. It is mainly used for DNS routing.

The ELB is used to distribute traffic.

DNS Server Type

• authoritative DNS server
  • There is a name resolution function.
• cache DNS server
  • Temporary DNS information storage
  • Reduced load, improved performance

 

What is Route53?

• Authoritative DNS servers provided by AWS
• Called Route53 because it operates on port 53
• AWS service for managed use of authoritative DNS server functions
• SLAs (quality assurance levels) guaranteeing 100% availability on the AWS side

 

Key Features of Route53

• Domain name registration
• DNS Routing
• health check

 

Basic Use of Route53

1. Domain name registration
2. Host Zone Settings
3. Set DNS records for host zone
4. Traffic routing configuration

 

What is the Host Zone?

Container that contains the routing method for the domain (example.com) and its subdomain (sub.example.com).

Host zones include public and private host zones.

 

Operation screen

Specification to create a domain to be operated by pressing the "Create Host Zone" button.

Domain names can be registered with any name.

DNS records (NS records, A records), routing policies, etc. are set for the created domain name.

 

 

 

 

public host zone

• Container that manages DNS records published on the Internet
• Define how traffic is routed to DNS domains on the Internet

A public host zone is a container that maintains DNS domain records published on the Internet that holds information about how traffic for a domain such as example.com is routed on the Internet or a specific domain

 

 

private host zone

• Container to manage DNS records in VPC
• Define how traffic is routed to the VPC's DNS domain
• Multiple VPCs in one private host zone

The same host zone can be used in a multi-region VPC as long as the VPCs are mutually accessible, which explains the private host zone

Another content of the private host zone is that it is possible to route domains in private subnets

 

 

 

 

routing

Route53 configures routing by policy

Type of routing method

• simple routing
• weighted routing
• latency routing
• positional routing
• multivalued routing
• traffic routing
• Geographic proximity Routing

 

Simple Routing

Respond to DNS queries based only on preconfigured values in record sets

Static mapping determines routing

 

Weighted Routing

Multiple endpoints Respond to DNS queries by weight settings

Routing to more highly weighted endpoints

 

failover routing

Respond to DNS queries for available resources based on health check results

Routing only to available resources

 

Multi-value routing (multiple-response routing)

Set IP addresses and change multiple values using up to eight separate records chosen at random

Perform health checks on a per-IP-address basis and return resource values by routing

Can improve availability and load balancing (not up to ELB)

 

Latency Routing

Responding to DNS queries due to region delays

Basically, reply to the user's nearest region.

Routed to the one with less delay between regions

 

When to use it?

Application users are located all over the world, and not all users use the system frequently, so if the load is low in some areas and high in others

This speeds up application processing by redirecting requests by users to regions that have better latency and are closer to the request.

 

Location Information Routing

Identify location by user's IP address and return different records for different regions.

Highly accurate record classification independent of network configuration

The Tokyo region can display a page in Japanese, and the US region can display a page in English.

Similar to geographic proximity routing based on users and resources, but partially different e.g. not based on resources

 

Geographic proximity Routing

Create geographic proximity rules based on user and resource location to route traffic

Bias can be set as needed to change the amount of traffic routed to a particular resource

Need to use traffic flow.

 

When to use it?

When you build a global web application that uses a configuration with EC2 instances and RDS across multiple regions

With geographic proximity routing, Amazon Route 53 routes traffic for a resource based on the geographic location of the user and resource. You can also change the amount of traffic routed to a particular resource as needed. To do so, you specify a value called bias. Bias increases or decreases the size of the geographic region from which the traffic routed to a resource is routed. To use geographic proximity routing, you must use Route 53 traffic flows.

 

 

 

traffic flow

Traditionally, complex routing policies were created using alias records.

Now complex policy settings are possible with visual flow through traffic flow.

 

Set the routing policy in the Root Record Set screen

Configure routing policy with traffic flow

 

traffic policy

To set up complex routing, traffic policy can be configured by setting up an order with traffic flows.

The Traffic Flow visual editor is used to create traffic policies. A traffic policy contains information about the routing configuration you are creating. This includes the routing policy to be used and the resources to which DNS traffic will be routed, such as the IP address of each EC2 instance and the domain name of each ELB load balancer. You can also associate health checks with endpoints so that Route 53 will only route traffic to healthy resources. This allows complex routing to be configured visually