Nginx vs Apache comparison - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

Key difference in handling connections

Which statement correctly describes how Nginx and Apache handle client connections?

A Both Nginx and Apache use process-driven, synchronous architectures.

B Both Nginx and Apache use event-driven, asynchronous architectures.

C Nginx uses an event-driven, asynchronous architecture, while Apache uses a process-driven, synchronous model.

D Apache uses an event-driven, asynchronous architecture, while Nginx uses a process-driven, synchronous model.

💡 Hint

Think about how each server manages multiple requests at the same time.

Nginx uses an event-driven model that handles many connections efficiently with fewer resources. Apache traditionally uses a process or thread per connection, which can be less efficient under heavy load.

💻 Command Output

intermediate

Check active worker processes

What is the output of the following command on a server running Nginx?

ps aux | grep nginx | grep -v grep

A Shows only one Nginx process running.

B Shows multiple Nginx worker processes and one master process running.

C Returns a syntax error due to incorrect command.

D Shows no output because Nginx is not running.

💡 Hint

Consider how Nginx manages its processes.

Nginx runs one master process and multiple worker processes to handle requests. The command lists all these processes except the grep command itself.

❓ Configuration

advanced

Load balancing configuration in Nginx

Which Nginx configuration snippet correctly sets up a simple round-robin load balancer for two backend servers?

A

upstream backend {
    server backend1.example.com weight=2;
    server backend2.example.com weight=3;
}

server {
    location / {
        proxy_pass http://backend;
    }
}

B

server {
    proxy_pass backend1.example.com backend2.example.com;
}

C

upstream backend {
    server backend1.example.com;
    server backend2.example.com;
    load_balance round_robin;
}

server {
    location / {
        proxy_pass http://backend;
    }
}

D

upstream backend {
    server backend1.example.com;
    server backend2.example.com;
}

server {
    location / {
        proxy_pass http://backend;
    }
}

💡 Hint

Look for the standard way to define upstream servers and proxy pass.

Option D correctly defines an upstream block with two servers and proxies requests to it. Option D adds weights which is valid but changes load balancing behavior. Option D and D have syntax errors or invalid directives.

❓ Troubleshoot

advanced

Diagnosing 502 Bad Gateway error

You have Nginx configured as a reverse proxy to an application server. When accessing the site, you get a 502 Bad Gateway error. Which is the most likely cause?

A The backend application server is not running or unreachable.

B Nginx configuration file syntax error.

C Nginx is running on a different port than the backend server.

D The client browser cache is corrupted.

💡 Hint

502 means Nginx cannot get a valid response from the backend.

A 502 Bad Gateway error usually means Nginx tried to connect to the backend server but failed because it is down or unreachable. Configuration syntax errors cause startup failures, not 502 errors. Port mismatch is a cause but is covered by unreachable backend. Browser cache does not cause 502.

✅ Best Practice

expert

Optimizing static content delivery

Which Nginx configuration snippet best improves performance by efficiently serving static files?

A

location /static/ {
    root /var/www/html;
    expires 30d;
    add_header Cache-Control "public";
    try_files $uri =404;
}

B

location /static/ {
    proxy_pass http://backend;
    expires 30d;
}

C

location /static/ {
    root /var/www/html;
    proxy_cache off;
}

D

location /static/ {
    root /var/www/html;
    deny all;
}

💡 Hint

Think about caching headers and direct file serving.

Option A sets caching headers and serves files directly from disk, improving performance. Option A proxies static files to backend, which is inefficient. Option A disables caching. Option A denies access to static files.

Practice

1. Which web server is known for using fewer resources and handling many connections efficiently?

easy

A. IIS

B. Apache

C. Nginx

D. Tomcat

Solution

1. Step 1: Understand resource usage

   Nginx is designed to use less memory and CPU by handling many connections asynchronously.

2. Step 2: Compare with Apache

   Apache uses more resources because it creates a new process or thread per connection, which is less efficient.

3. Final Answer:

   Nginx -> Option C

4. Quick Check:

   Low resource use = Nginx [OK]

Hint: Nginx = efficient, Apache = flexible [OK]

Common Mistakes:

• Confusing Apache as more efficient
• Thinking IIS or Tomcat are similar to Nginx
• Assuming all web servers use same resources

2. Which of the following is the correct way to start the Nginx service on a Linux system using systemd?

easy

A. systemctl start nginx

B. nginx start

C. service nginx start

D. start nginx

Solution

1. Step 1: Identify systemd command

   Modern Linux systems use systemctl to manage services.

2. Step 2: Correct syntax for starting Nginx

   The command is systemctl start nginx to start the Nginx service.

3. Final Answer:

   systemctl start nginx -> Option A

4. Quick Check:

   Use systemctl for services [OK]

Hint: Use systemctl to manage services on modern Linux [OK]

Common Mistakes:

• Using old service command on systemd systems
• Typing nginx start which is invalid
• Using start nginx which is not a command

3. Given the following Nginx and Apache configurations, which server will handle 10,000 simultaneous connections more efficiently?

# Nginx: event-driven, asynchronous handling
# Apache: process/thread per connection model

medium

A. Nginx will handle better due to asynchronous event-driven model

B. Neither can handle that many connections

C. Both handle equally well

D. Apache will handle better due to process isolation

Solution

1. Step 1: Understand connection handling models

   Nginx uses an event-driven, asynchronous model that handles many connections with fewer resources.

2. Step 2: Compare Apache's model

   Apache creates a new process or thread per connection, which uses more memory and CPU, limiting scalability.

3. Final Answer:

   Nginx will handle better due to asynchronous event-driven model -> Option A

4. Quick Check:

   Event-driven = better for many connections [OK]

Hint: Event-driven servers handle many connections efficiently [OK]

Common Mistakes:

• Assuming process isolation means better performance
• Thinking Apache scales as well as Nginx
• Ignoring resource limits on Apache

4. You configured Apache to serve static files but notice high CPU usage under load. What is a likely cause compared to Nginx?

medium

A. Apache caches static files inefficiently

B. Apache uses more CPU because it creates a process per request

C. Nginx does not support static files

D. Apache does not support HTTP/1.1

Solution

1. Step 1: Analyze Apache's process model

   Apache creates a new process or thread for each request, increasing CPU usage under load.

2. Step 2: Compare with Nginx's approach

   Nginx uses an event-driven model that handles many requests with fewer processes, reducing CPU load.

3. Final Answer:

   Apache uses more CPU because it creates a process per request -> Option B

4. Quick Check:

   Process per request = higher CPU [OK]

Hint: Process per request = more CPU usage [OK]

Common Mistakes:

• Thinking Apache caches static files poorly
• Believing Nginx lacks static file support
• Incorrectly assuming Apache lacks HTTP/1.1 support

5. You want to serve a high-traffic website with many simultaneous users and low memory usage. Which setup is best and why?

hard

A. Use Nginx only as a reverse proxy, Apache for static files

B. Use Apache with many worker processes for flexibility

C. Use Apache with default prefork module for stability

D. Use Nginx for event-driven handling and low memory use

Solution

1. Step 1: Identify requirements

   High traffic and low memory use require efficient connection handling and low resource consumption.

2. Step 2: Evaluate server models

   Nginx uses an event-driven model that handles many connections with low memory, ideal for high traffic.

3. Step 3: Compare other options

   Apache with many workers uses more memory; prefork is stable but heavy; using Nginx only as proxy adds complexity.

4. Final Answer:

   Use Nginx for event-driven handling and low memory use -> Option D

5. Quick Check:

   Event-driven + low memory = Nginx best [OK]

Hint: For high traffic and low memory, choose Nginx [OK]

Common Mistakes:

• Choosing Apache for low memory use
• Ignoring Nginx's event-driven advantage
• Overcomplicating with mixed setups