Chapter 10 - Route 53

Question 1

Alias record

Answer 1

• Given the choice in a scenario-based question always choose an alias record over a CNAME.
• They are unique to AWS.
• So it’s a way of translating your naked domain name to a resource.

Question 2

CNAME

Answer 2

allows you to translate a sub domain names from one to another.

Question 3

common DNS record types

Answer 3

• Start of authority record (SOA)
• CNAME
• NS records or name server records
• A Records essentially just turn our web addresses in to IP addresses.

Question 4

7 different routing policies

Answer 4

1. simple routing
2. weighted routing
3. latency based routing
4. failover routing
5. geolocation routing
6. geoproximity routing

Question 5

health checks

Answer 5

• You can set a health check on individual record sets
• If a record sets fails a health check it’s going to be removed from Route 53 until it passes the health check.
• You can even configure SNS notifications to alert you about failed health checks.

Question 6

simple routing policy

Answer 6

• So if you choose simple routing policy, you can only have one record with multiple IP addresses.
• And if you specify multiple values in a record, Route 53 returns all values to the user in a random order.
• they do not work with health checks

Question 7

Weighted routing policies

Answer 7

• it would just take the weighting and add up the sum of all the weighting and then divide by the individual weighting by that.
• And that’s how it calculates the percentages.

Question 8

latency based routing policies

Answer 8

• So we’ve got our user they’re in South Africa.
• They connecting into Route 53.
• They get a 54 millisecond latency when connecting into eu-west-2 or 300 millisecond latency when connected into ap-southeast-2.
• So Route 53 will give them the lowest latency possible and then will redirect them to eu-west-2.
• So if you see an exam question that’s talking about latency, I want you to think about latency routing.

Question 9

Failover routing

Answer 9

• fail over routing will have a health check on each region.
• And if we lose a region, it will switch from our active site to our passive site automatically.
• So it’s a way of just failing over.
• So if you see a mention in the scenario based question about how to failover from one site to another, I want you to think of failover routing.

Question 10

Geolocation routing

Answer 10

• So this is where we’ve got a group of customers.They might be European customers and we want to only send them to our European web servers.
• It might be that those European web servers have been configured with Euros or with the local languages.
• So it might be in French or Italian.
• And then we have our US-based customers. And then they basically only want to go to our web servers in the US.
• So again you might get a scenario based question where it’s talking about how can you make sure that a group of users in a particular location only go to a group of web servers in a particular location.
• And as soon as you hear the word location in a scenario based question talking about Route 53, I want you to think of Geolocation routing.

Question 11

Geoproximity routing

Answer 11

basically lets Amazon Route 53 route your traffic to resources based on the geographic location of your users and resources.

Question 12

bias

Answer 12

• Basically expands or shrinks the size of a geographic region from which traffic is routed to a resource.
• And to use geo proximity routing you must be using Route 53 Traffic Flow.
• Route 53 Traffic Flow was that GUI where we can do all kinds of complicated routing architectures with Route 53.

Question 13

Multivalue Answer Routing

Answer 13

• We’ve got our user they’re connecting into hellocloudgurus.com or hellocloudgurus123.com. Our first IP address is 30.0.0.1.
• We then have a second record which is got another IP address of 30.0.0.2.
• And we have health checks on each record.
• And so if we lose our first first record, Route 53 will automatically just redirect all our traffic to healthy instance at 30.0.0.2.