Failover routing for disaster recovery in AWS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a Route 53 failover routing policy for disaster recovery.

AWS

resource "aws_route53_record" "failover" {
  zone_id = var.zone_id
  name    = "app.example.com"
  type    = "A"
  ttl     = 60
  set_identifier = "Primary"
  failover = "[1]"
  records = [aws_instance.primary.public_ip]
}

Drag options to blanks, or click blank then click option'

ASECONDARY

BPRIMARY

CACTIVE

DPASSIVE

Attempts:

3 left

💡 Hint

Common Mistakes

Using SECONDARY for the primary record.

Using ACTIVE or PASSIVE which are invalid values.

The failover value must be set to PRIMARY for the primary resource in Route 53 failover routing.

2fill in blank

medium

Complete the code to set the failover routing policy for the secondary record.

AWS

resource "aws_route53_record" "failover_secondary" {
  zone_id = var.zone_id
  name    = "app.example.com"
  type    = "A"
  ttl     = 60
  set_identifier = "Secondary"
  failover = "[1]"
  records = [aws_instance.secondary.public_ip]
}

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APASSIVE

BPRIMARY

CACTIVE

DSECONDARY

Attempts:

3 left

💡 Hint

Common Mistakes

Using PRIMARY for the secondary record.

Using ACTIVE or PASSIVE which are invalid values.

The failover value must be set to SECONDARY for the secondary resource in Route 53 failover routing.

3fill in blank

hard

Fix the error in the health check configuration for failover routing.

AWS

resource "aws_route53_health_check" "primary_health" {
  fqdn              = "app.example.com"
  port              = 80
  type              = "[1]"
  resource_path     = "/health"
  failure_threshold = 3
}

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AHTTPS

BTCP

CHTTP

DPING

Attempts:

3 left

💡 Hint

Common Mistakes

Using TCP which only checks port connectivity.

Using PING which is not suitable for HTTP health checks.

The health check type should be HTTP to check the web server's health endpoint.

4fill in blank

hard

Fill both blanks to correctly associate the health check with the Route 53 record and enable failover.

AWS

resource "aws_route53_record" "failover_primary" {
  zone_id = var.zone_id
  name    = "app.example.com"
  type    = "A"
  ttl     = 60
  set_identifier = "Primary"
  failover = "[1]"
  health_check_id = aws_route53_health_check.primary_health.[2]
  records = [aws_instance.primary.public_ip]
}

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APRIMARY

Bid

Carn

DSECONDARY

Attempts:

3 left

💡 Hint

Common Mistakes

Using SECONDARY for failover on primary record.

Using 'arn' instead of 'id' for health_check_id.

The failover must be set to PRIMARY and the health check ID is accessed via id property.

5fill in blank

hard

Fill all three blanks to create a secondary failover record with health check association.

AWS

resource "aws_route53_record" "failover_secondary" {
  zone_id = var.zone_id
  name    = "app.example.com"
  type    = "A"
  ttl     = 60
  set_identifier = "Secondary"
  failover = "[1]"
  health_check_id = aws_route53_health_check.secondary_health.[2]
  records = [aws_instance.secondary.[3]]
}

Drag options to blanks, or click blank then click option'

ASECONDARY

Bid

Cpublic_ip

Dprivate_ip

Attempts:

3 left

💡 Hint

Common Mistakes

Using PRIMARY for secondary failover.

Using 'arn' instead of 'id' for health_check_id.

Using private_ip instead of public_ip.

The failover must be SECONDARY, health check ID accessed by id, and the record uses the secondary instance's public_ip.

Practice

1. What is the main purpose of failover routing in disaster recovery?

easy

A. To block all traffic during maintenance

B. To increase the speed of the primary server

C. To reduce the cost of cloud services

D. To automatically send users to a backup server if the main server fails

Solution

1. Step 1: Understand failover routing purpose

   Failover routing is designed to keep services available by switching traffic to a backup if the main server fails.

2. Step 2: Eliminate unrelated options

   Options about speed, cost, or blocking traffic do not describe failover routing's main goal.

3. Final Answer:

   To automatically send users to a backup server if the main server fails -> Option D

4. Quick Check:

   Failover routing = automatic backup switch [OK]

Hint: Failover means switch to backup when main fails [OK]

Common Mistakes:

• Confusing failover with performance improvement
• Thinking failover blocks traffic
• Assuming failover reduces costs

2. Which AWS Route 53 routing policy is used to implement failover routing?

easy

A. Geolocation routing policy

B. Latency routing policy

C. Failover routing policy

D. Weighted routing policy

Solution

1. Step 1: Identify routing policies in Route 53

   Route 53 offers several routing policies, including latency, geolocation, weighted, and failover.

2. Step 2: Match failover routing policy to disaster recovery

   Failover routing policy is specifically designed to route traffic to a backup when the primary fails.

3. Final Answer:

   Failover routing policy -> Option C

4. Quick Check:

   Failover routing policy = failover setup [OK]

Hint: Failover routing policy is named for failover use [OK]

Common Mistakes:

• Choosing latency or weighted policies for failover
• Confusing geolocation with failover
• Not knowing Route 53 routing policy names

3. Given this Route 53 failover setup: Primary health check fails, what happens to user traffic?
Primary: IP 10.0.0.1 (health check enabled)
Secondary: IP 10.0.0.2 (backup)

medium

A. Traffic switches to secondary IP 10.0.0.2

B. Traffic is split evenly between primary and secondary

C. Traffic is blocked until primary recovers

D. Traffic continues to primary IP 10.0.0.1

Solution

1. Step 1: Understand health check failure effect

   If the primary health check fails, Route 53 detects the primary is unhealthy.

2. Step 2: Apply failover routing behavior

   Failover routing sends traffic to the secondary (backup) IP when primary is unhealthy.

3. Final Answer:

   Traffic switches to secondary IP 10.0.0.2 -> Option A

4. Quick Check:

   Primary down = traffic to backup [OK]

Hint: Failover sends traffic to backup if primary fails health check [OK]

Common Mistakes:

• Assuming traffic stays on primary despite failure
• Thinking traffic is blocked during failover
• Believing traffic splits evenly without weighting

4. You configured failover routing but traffic never switches to the backup server during primary failure. What is the most likely cause?

medium

A. Latency routing policy is used instead of failover

B. Health check is not associated with the primary record

C. Backup server IP address is incorrect

D. TTL value is set to zero

Solution

1. Step 1: Check health check association

   Failover routing requires the primary record to have a health check to detect failure.

2. Step 2: Understand impact of missing health check

   If the health check is missing or not linked, Route 53 never detects primary failure, so no failover occurs.

3. Final Answer:

   Health check is not associated with the primary record -> Option B

4. Quick Check:

   Failover needs health check linked to primary [OK]

Hint: Failover needs health check linked to primary record [OK]

Common Mistakes:

• Ignoring health check association
• Blaming backup IP without checking health check
• Confusing routing policies
• Misunderstanding TTL effects

5. You want to design a disaster recovery setup using Route 53 failover routing with two regions: primary in us-east-1 and backup in us-west-2. Which configuration ensures automatic failover with minimal downtime?

hard

A. Create two records with failover routing; primary record with health check in us-east-1, secondary record without health check in us-west-2

B. Create two records with weighted routing; assign 100% weight to primary and 0% to backup

C. Create two records with geolocation routing; route us-east traffic to primary and us-west traffic to backup

D. Create two records with latency routing; primary in us-east-1 and backup in us-west-2

Solution

1. Step 1: Understand failover routing setup

   Failover routing requires a primary record with a health check and a secondary record without a health check as backup.

2. Step 2: Evaluate options for disaster recovery

   Create two records with failover routing; primary record with health check in us-east-1, secondary record without health check in us-west-2 correctly sets primary with health check and backup without health check, enabling automatic failover.

3. Step 3: Eliminate other options

   Weighted routing does not provide automatic failover; geolocation routes by location, not health; latency routing routes by speed, not failure.

4. Final Answer:

   Create two records with failover routing; primary record with health check in us-east-1, secondary record without health check in us-west-2 -> Option A

5. Quick Check:

   Failover needs primary health check and backup record [OK]

Hint: Primary needs health check; backup record no health check [OK]

Common Mistakes:

• Using weighted routing instead of failover
• Assigning health check to backup record
• Confusing geolocation with failover
• Expecting latency routing to handle failover