20 NGINX Interview Questions and Answers

NGINX is a web server that can be used to host websites and applications. It is a popular choice for developers due to its high performance and scalability. If you are applying for a position that involves working with NGINX, it is important to be prepared to answer questions about it during your interview. In this article, we will review some of the most common NGINX interview questions and provide tips on how to answer them.

NGINX Interview Questions and Answers

Here are 20 commonly asked NGINX interview questions and answers to prepare you for your interview:

1. What is NGINX?

NGINX is a web server that can also be used as a reverse proxy, load balancer, and HTTP cache.

2. Can you explain the main features of NGINX?

NGINX is a high-performance web server that is known for its stability, rich feature set, simple configuration, and low resource consumption. NGINX can be used as a standalone web server, or it can be used in conjunction with other web servers, such as Apache, to provide additional features and functionality. NGINX is often used to improve website performance by caching static content and handling concurrent requests more efficiently than other web servers.

3. How would you configure NGINX as a web server?

NGINX can be configured as a web server by editing the nginx.conf file. In the file, you would need to set the root directive to point to the location of your website’s files. You would also need to set up any desired virtual hosts.

4. What are some common uses for NGINX?

NGINX is a web server that can also be used as a reverse proxy, load balancer, and HTTP cache.

5. Why do you think NGINX has become so popular in recent years?

NGINX has become popular in recent years for a variety of reasons. First, it is very lightweight and efficient, which makes it ideal for use in high-traffic web applications. Additionally, it has a very simple configuration syntax, which makes it easy to set up and maintain. Finally, NGINX can be used as a reverse proxy server, which gives it the ability to load balance web traffic across multiple servers.

6. What’s your opinion on using Apache instead of NGINX?

I believe that NGINX is a better option than Apache for a number of reasons. NGINX is faster and uses less memory, which is important for high-traffic sites. It also has a number of features that Apache does not, such as load balancing and reverse proxying.

7. What are the main configuration files used to set up and run NGINX?

The main configuration files used to set up and run NGINX are nginx.conf and sites-enabled/default. nginx.conf is the main configuration file for NGINX, which can be used to set up various options and settings. sites-enabled/default is the default configuration file for NGINX, which can be used to set up the server and enable various features.

8. Is it possible to have multiple configuration files for running NGINX? If yes, then how can we combine these into one single file?

Yes, it is possible to have multiple configuration files for NGINX. In order to combine these into one single file, you can use the “include” directive. This directive will tell NGINX to read in and process any other configuration files that are specified.

9. When configuring NGINX with SSL certificates, what kind of certificate should I use – self-signed or trusted? What does “trusted” mean exactly?

If you are configuring NGINX to serve as a public-facing web server, then you will want to use a trusted SSL certificate. This means that the certificate has been signed by a trusted Certificate Authority (CA), and provides assurance to visitors that your site is legitimate. A self-signed certificate will work for serving content over SSL, but visitors will see a warning message in their browser indicating that the certificate is not trusted.

10. What is the best way to monitor activity within an NGINX process?

The best way to monitor activity within an NGINX process is to use the NGINX Plus API. This API provides access to detailed information about the server activity, including request and response times, client IP addresses, and more. This information can be used to troubleshoot performance issues or to simply keep an eye on server activity.

11. What are some ways to debug problems with NGINX?

There are a few ways that you can debug problems with NGINX. One way is to use the error_log directive to log any errors that occur. Another way is to use the debug_connection directive to log all of the events that occur during a connection. Finally, you can also use the strace utility to trace system calls and signals.

12. Can you explain what a load balancer is and why it might be needed when working with NGINX?

A load balancer is a device that is used to distribute traffic across multiple servers. This is often done in order to improve performance and to ensure that no single server is overwhelmed with requests. In a situation where NGINX is being used to serve multiple websites, a load balancer can be used to distribute traffic across the different NGINX servers that are handling each website.

13. What happens if there isn’t enough memory available on my system to run NGINX?

NGINX will not start if there isn’t enough memory available on your system. This is because NGINX requires a certain amount of memory in order to run properly. If NGINX doesn’t have enough memory, it will simply exit and not start.

14. What are some other alternatives to NGINX that developers might consider using?

Some other popular web servers that developers might consider using instead of NGINX are Apache HTTP Server and Microsoft IIS.

15. What are some ways to ensure high availability when using NGINX?

There are a few different ways to ensure high availability when using NGINX. One way is to use a tool like keepalived which can monitor the NGINX server and automatically failover to a standby server if the primary server goes down. Another way is to use a load balancer in front of NGINX to distribute traffic across multiple servers.

16. What is the most important thing to know before upgrading from NGINX 1.x to 2.x?

The biggest thing to keep in mind when upgrading from NGINX 1.x to 2.x is that there have been some major changes to the configuration file format. In NGINX 2.x, the configuration file is now organized into different sections, each with its own set of directives. This can be a bit confusing at first, but once you get used to it, it’s not too bad. Just be sure to read the documentation carefully before upgrading.

17. What are some good resources to learn more about NGINX?

Some good resources to learn more about NGINX include the NGINX website itself, which has a wealth of documentation on the server and its capabilities, as well as the NGINX Plus Admin Guide. Additionally, there are a number of online tutorials and blog posts that can introduce you to the basics of NGINX and help you get started with using the server.

18. Can you explain what HTTP/2 is? Why is it better than earlier versions of HTTP like 1.1?

HTTP/2 is a newer version of the HTTP protocol that was designed to address some of the shortcomings of earlier versions like 1.1. One of the biggest advantages of HTTP/2 is that it uses a multiplexing technique to allow multiple requests to be sent over a single connection, which can lead to faster page loading times. Additionally, HTTP/2 uses header compression to reduce the amount of data that needs to be sent over the network, and it also supports server push, which allows a server to proactively send resources to a client before they even know they need them.

19. Can you provide me with a few examples where using HTTP/2 has made a real difference for end users?

1. HTTP/2 has been shown to improve page load times by up to 50%.
2. HTTP/2 can improve web performance by reducing latency and eliminating the need for multiple round trips between the client and server.
3. HTTP/2 can improve web security by encrypting all data transfers between the client and server.
4. HTTP/2 can improve web usability by allowing for more efficient use of bandwidth and resources.

20. What are some different types of authentication methods supported by NGINX?

NGINX can support a few different authentication methods, the most common being Basic Auth and Digest Auth.