Routing policies (simple, weighted, latency) in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a simple routing policy in AWS Route 53?

A simple routing policy routes traffic to a single resource, like a web server. It is like giving your friend one address to visit without any special rules.

intermediate

How does weighted routing policy work in AWS Route 53?

Weighted routing lets you split traffic between multiple resources by assigning weights. For example, 70% of visitors go to server A and 30% to server B, like sharing slices of a pizza.

intermediate

What is the purpose of latency routing policy?

Latency routing sends users to the resource with the lowest network delay. It’s like choosing the closest store to get your item faster.

beginner

Can you use weighted routing to test a new version of your website?

Yes, weighted routing can send a small percentage of users to the new version while most use the old one. This helps test safely without affecting everyone.

advanced

What happens if latency routing cannot find a resource with lower latency?

If no resource has lower latency, Route 53 routes traffic to the next best resource based on latency measurements, ensuring users get the fastest possible response.

Which routing policy sends all traffic to a single resource without distribution?

A Simple routing

B Weighted routing

C Latency routing

D Failover routing

Simple routing sends all traffic to one resource without splitting or conditions.

How does weighted routing distribute traffic?

A Based on resource health

B Based on geographic location

C Based on assigned weights

D Based on lowest latency

Weighted routing uses weights to split traffic proportionally among resources.

Latency routing directs users to which resource?

A The resource with the lowest cost

B The resource with the lowest network delay

C The resource with the highest capacity

D The resource with the most traffic

Latency routing chooses the resource with the lowest network delay to improve user experience.

Which routing policy is best for testing new features with limited users?

A Weighted routing

B Simple routing

C Latency routing

D Geolocation routing

Weighted routing allows sending a small percentage of traffic to a new version for testing.

If latency routing cannot find a faster resource, what happens?

A Traffic is dropped

B Traffic is routed randomly

C Traffic is routed to the first resource created

D Traffic is routed to the next best resource by latency

Route 53 routes traffic to the next best resource based on latency measurements.

Explain the differences between simple, weighted, and latency routing policies in AWS Route 53.

Think about how traffic is directed in each policy.

Describe a real-life scenario where weighted routing would be useful.

Consider how you might share something between friends in parts.

Practice

1. What does a simple routing policy do in AWS Route 53?

easy

A. Sends all traffic to a single resource

B. Splits traffic based on weights

C. Routes traffic based on lowest latency

D. Routes traffic randomly among resources

Solution

1. Step 1: Understand simple routing purpose

   Simple routing sends all user requests to one resource without splitting or conditions.

2. Step 2: Compare with other routing types

   Weighted routing splits traffic, latency routing chooses fastest server, so they differ from simple routing.

3. Final Answer:

   Sends all traffic to a single resource -> Option A

4. Quick Check:

   Simple routing = single destination [OK]

Hint: Simple routing means one destination for all traffic [OK]

Common Mistakes:

• Confusing simple routing with weighted routing
• Thinking simple routing balances traffic
• Assuming simple routing uses latency

2. Which of the following is the correct way to configure a weighted routing policy in AWS Route 53?

easy

A. Assign weights to each record to split traffic

B. Set a single IP address for all traffic

C. Use latency measurements to route traffic

D. Randomly assign traffic without weights

Solution

1. Step 1: Identify weighted routing configuration

   Weighted routing requires assigning numeric weights to DNS records to control traffic distribution.

2. Step 2: Eliminate incorrect options

   Single IP is simple routing, latency routing uses latency, random without weights is invalid.

3. Final Answer:

   Assign weights to each record to split traffic -> Option A

4. Quick Check:

   Weighted routing = assign weights [OK]

Hint: Weighted routing needs numeric weights per record [OK]

Common Mistakes:

• Confusing weighted with simple routing
• Using latency instead of weights
• Not assigning any weight values

3. Given two servers in different regions with latency routing enabled, which server will Route 53 direct a user to?

medium

A. The server with the highest weight

B. The server with the lowest latency from the user

C. The server with the most traffic

D. The server randomly chosen

Solution

1. Step 1: Understand latency routing behavior

   Latency routing sends users to the server with the lowest network delay from their location.

2. Step 2: Exclude other options

   Weight is for weighted routing, traffic volume is not a factor, random choice is not latency routing.

3. Final Answer:

   The server with the lowest latency from the user -> Option B

4. Quick Check:

   Latency routing = fastest server [OK]

Hint: Latency routing picks fastest server by user location [OK]

Common Mistakes:

• Mixing weighted and latency routing concepts
• Assuming traffic volume affects routing
• Thinking routing is random

4. You configured weighted routing but all traffic still goes to one server. What is the most likely cause?

medium

A. DNS records have different names

B. Latency routing is enabled instead of weighted

C. Simple routing policy is selected by mistake

D. Weights are set to zero for other servers

Solution

1. Step 1: Check weight values in weighted routing

   If weights for other servers are zero, all traffic goes to the server with non-zero weight.

2. Step 2: Rule out other causes

   Latency routing or simple routing would behave differently; different record names do not affect routing weights.

3. Final Answer:

   Weights are set to zero for other servers -> Option D

4. Quick Check:

   Zero weights = no traffic [OK]

Hint: Check weights are not zero for all servers [OK]

Common Mistakes:

• Confusing routing policy type
• Ignoring zero weights effect
• Assuming DNS names affect weighted routing

5. You want to route 70% of traffic to a primary server and 30% to a backup server, but also ensure users connect to the lowest latency server within those groups. Which routing policy setup should you use?

hard

A. Use latency routing only with weights assigned

B. Use simple routing with latency routing

C. Use weighted routing with latency routing inside each weight group

D. Use weighted routing only without latency

Solution

1. Step 1: Understand combined routing needs

   You want to split traffic by weight, then route users to lowest latency server within each group.

2. Step 2: Identify correct routing policy combination

   Weighted routing controls traffic percentage, latency routing directs users to fastest server inside each weighted group.

3. Step 3: Eliminate incorrect options

   Simple routing cannot split traffic; latency routing alone can't assign weights; weighted routing alone ignores latency.

4. Final Answer:

   Use weighted routing with latency routing inside each weight group -> Option C

5. Quick Check:

   Combine weighted + latency for split and speed [OK]

Hint: Combine weighted and latency routing for split and speed [OK]

Common Mistakes:

• Trying to use simple routing for traffic split
• Ignoring latency inside weighted groups
• Assuming latency routing can split traffic by weight