Load balancer types comparison in GCP - Step-by-Step Execution

Process Flow - Load balancer types comparison

Client sends request

↓

Load Balancer receives request

↓

Forward request to backend based on type

↓

Backend service processes request

↓

Response sent back to client

Client requests go to a load balancer, which picks a type based on protocol and forwards to backend services, then returns responses.

Execution Sample

GCP

Client -> HTTP(S) LB -> Backend
Client -> TCP Proxy LB -> Backend
Client -> Network LB -> Backend

Shows how client requests flow through different GCP load balancer types to backend services.

Process Table

Step	Load Balancer Type	Protocol	Action	Backend Target
1	HTTP(S) Load Balancer	HTTP/HTTPS	Receives HTTP/HTTPS request	Global HTTP(S) backend service
2	HTTP(S) Load Balancer	HTTP/HTTPS	Performs URL/path routing, SSL termination	Sends request to backend instance group or service
3	TCP Proxy Load Balancer	TCP	Receives TCP request	Global TCP backend service
4	TCP Proxy Load Balancer	TCP	Terminates SSL if configured	Sends request to backend instance group
5	Network Load Balancer	TCP/UDP	Receives TCP/UDP request	Regional backend instance group
6	Network Load Balancer	TCP/UDP	Passes request directly without SSL termination	Sends request to backend instances
7	Exit	-	No more requests	-

💡 All requests processed and forwarded to appropriate backend based on load balancer type and protocol.

Status Tracker

Variable	Start	After Step 2	After Step 4	After Step 6	Final
Request Protocol	Client sends HTTP	HTTP/HTTPS handled	TCP handled	TCP/UDP handled	Request completed
Load Balancer Type	None	HTTP(S) LB active	TCP Proxy LB active	Network LB active	Idle
Backend Target	None	HTTP(S) backend	TCP backend	Network backend	Response sent

Key Moments - 3 Insights

Why does HTTP(S) Load Balancer perform SSL termination but Network Load Balancer does not?

HTTP(S) Load Balancer is designed for global HTTP/HTTPS traffic and can decrypt SSL to inspect requests (see execution_table steps 1-2). Network Load Balancer works at lower network level and passes encrypted traffic directly (see steps 5-6).

Why is TCP Proxy Load Balancer considered global but Network Load Balancer is regional?

TCP Proxy Load Balancer can route traffic globally to backend services anywhere (step 3-4), while Network Load Balancer routes traffic only within a region (step 5-6).

What happens if a UDP request is sent to HTTP(S) Load Balancer?

HTTP(S) Load Balancer only supports HTTP/HTTPS protocols (step 1-2). UDP requests are not supported and will fail or be rejected.

Visual Quiz - 3 Questions

Look at the execution_table, at which step does SSL termination happen for HTTP(S) Load Balancer?

A Step 1

B Step 2

C Step 4

D Step 6

💡 Hint

Check the 'Action' column for HTTP(S) Load Balancer steps in execution_table.

According to variable_tracker, what is the Load Balancer Type after Step 4?

A HTTP(S) Load Balancer

B Network Load Balancer

C TCP Proxy Load Balancer

D None

💡 Hint

Look at the 'Load Balancer Type' row and the 'After Step 4' column in variable_tracker.

If a UDP request is sent, which Load Balancer type from execution_table can handle it?

A HTTP(S) Load Balancer

B TCP Proxy Load Balancer

C Network Load Balancer

D None

💡 Hint

Check the 'Protocol' column for each Load Balancer type in execution_table.

Concept Snapshot

Load balancers distribute client requests to backend services.
HTTP(S) Load Balancer handles HTTP/HTTPS globally with SSL termination.
TCP Proxy Load Balancer handles TCP globally, can terminate SSL.
Network Load Balancer handles TCP/UDP regionally, passes traffic directly.
Choose based on protocol and global vs regional needs.

Full Transcript

This visual execution shows how different Google Cloud Platform load balancers handle client requests. The client sends a request which reaches a load balancer. The load balancer type is chosen based on the protocol: HTTP(S) Load Balancer for HTTP/HTTPS, TCP Proxy Load Balancer for TCP, and Network Load Balancer for TCP/UDP. HTTP(S) Load Balancer performs SSL termination and URL routing globally. TCP Proxy Load Balancer can terminate SSL and routes TCP traffic globally. Network Load Balancer passes TCP/UDP traffic regionally without SSL termination. Variables like request protocol, load balancer type, and backend target change as the request flows through steps. Key moments clarify SSL termination differences, global vs regional scope, and protocol support. Quizzes test understanding of SSL termination step, load balancer type after steps, and UDP support. The snapshot summarizes load balancer types and their main features for quick reference.

Practice

1. Which GCP load balancer type is best suited for distributing HTTP and HTTPS traffic globally with SSL termination?

easy

A. TCP Proxy Load Balancer

B. Internal Load Balancer

C. Network Load Balancer

D. HTTP(S) Load Balancer

Solution

1. Step 1: Understand the traffic type

   HTTP and HTTPS traffic require Layer 7 (application layer) handling with SSL termination.

2. Step 2: Match load balancer capabilities

   HTTP(S) Load Balancer supports global distribution and SSL termination for web traffic.

3. Final Answer:

   HTTP(S) Load Balancer -> Option D

4. Quick Check:

   HTTP/HTTPS + SSL termination = HTTP(S) Load Balancer [OK]

Hint: Web traffic with SSL? Pick HTTP(S) Load Balancer [OK]

Common Mistakes:

• Confusing TCP Proxy with HTTP(S) for web traffic
• Choosing Network Load Balancer for HTTPS termination
• Using Internal Load Balancer for global traffic

2. Which GCP load balancer type uses a regional forwarding rule and supports TCP and UDP traffic without SSL termination?

easy

A. HTTP(S) Load Balancer

B. Network Load Balancer

C. TCP Proxy Load Balancer

D. Internal Load Balancer

Solution

1. Step 1: Identify the traffic and forwarding rule type

   TCP and UDP traffic with regional forwarding rules indicates a Layer 4 load balancer.

2. Step 2: Match with GCP load balancer types

   Network Load Balancer supports TCP/UDP traffic regionally without SSL termination.

3. Final Answer:

   Network Load Balancer -> Option B

4. Quick Check:

   TCP/UDP + regional + no SSL = Network Load Balancer [OK]

Hint: TCP/UDP regional traffic? Use Network Load Balancer [OK]

Common Mistakes:

• Choosing HTTP(S) Load Balancer for UDP traffic
• Confusing TCP Proxy with Network Load Balancer
• Selecting Internal Load Balancer for external traffic

3. Given this scenario: You want to load balance TCP traffic globally with SSL offloading. Which GCP load balancer type will you use?

client -> GCP LB -> backend instances (TCP with SSL offloading)

medium

A. TCP Proxy Load Balancer

B. Internal Load Balancer

C. Network Load Balancer

D. HTTP(S) Load Balancer

Solution

1. Step 1: Analyze traffic and SSL offloading need

   TCP traffic with SSL offloading requires Layer 4 proxy with SSL termination.

2. Step 2: Match with GCP load balancer types

   TCP Proxy Load Balancer supports global TCP traffic with SSL offloading.

3. Final Answer:

   TCP Proxy Load Balancer -> Option A

4. Quick Check:

   Global TCP + SSL offloading = TCP Proxy Load Balancer [OK]

Hint: Global TCP + SSL offload? Use TCP Proxy Load Balancer [OK]

Common Mistakes:

• Choosing Network Load Balancer which lacks SSL offloading
• Selecting HTTP(S) Load Balancer for TCP traffic
• Using Internal Load Balancer for external traffic

4. You configured an Internal Load Balancer but your clients outside the VPC cannot access the service. What is the most likely cause?

medium

A. Internal Load Balancer only supports traffic inside the VPC

B. You forgot to enable global forwarding rules

C. Internal Load Balancer does not support TCP traffic

D. You need to use HTTP(S) Load Balancer for internal traffic

Solution

1. Step 1: Understand Internal Load Balancer scope

   Internal Load Balancer is designed for traffic inside a VPC or connected networks only.

2. Step 2: Identify access limitation

   Clients outside the VPC cannot reach Internal Load Balancer because it does not expose external IPs.

3. Final Answer:

   Internal Load Balancer only supports traffic inside the VPC -> Option A

4. Quick Check:

   Internal LB = VPC-only traffic [OK]

Hint: Internal LB is VPC-only; external clients can't connect [OK]

Common Mistakes:

• Assuming Internal LB supports global forwarding
• Thinking Internal LB supports external TCP traffic
• Confusing Internal LB with HTTP(S) Load Balancer

5. You have a multi-region web app serving HTTP and HTTPS traffic with backend services in multiple zones. You want to minimize latency and provide automatic failover. Which GCP load balancer type should you choose and why?

hard

A. Network Load Balancer because it supports UDP and TCP globally

B. Internal Load Balancer because it routes traffic inside the VPC

C. HTTP(S) Load Balancer because it offers global load balancing with SSL termination and health checks

D. TCP Proxy Load Balancer because it handles TCP traffic with SSL offloading

Solution

1. Step 1: Analyze requirements for multi-region HTTP/HTTPS app

   Needs global load balancing, SSL termination, low latency, and failover.

2. Step 2: Match load balancer features

   HTTP(S) Load Balancer supports global distribution, SSL termination, health checks, and automatic failover.

3. Step 3: Exclude other options

   Network Load Balancer is regional and lacks SSL termination; Internal Load Balancer is internal-only; TCP Proxy is for TCP, not HTTP/HTTPS.

4. Final Answer:

   HTTP(S) Load Balancer because it offers global load balancing with SSL termination and health checks -> Option C

5. Quick Check:

   Multi-region HTTP/HTTPS + failover = HTTP(S) Load Balancer [OK]

Hint: Global web app? Pick HTTP(S) Load Balancer for SSL and failover [OK]

Common Mistakes:

• Choosing Network Load Balancer for HTTP/HTTPS global traffic
• Using Internal Load Balancer for external multi-region access
• Selecting TCP Proxy Load Balancer for HTTP traffic