Linux Admin - Nginx Server Interview Question and Answers

What is Nginx Server?
Nginx (pronounced "engine x") is an open source web server and a reverse proxy server for HTTP, SMTP, POP3, and IMAP protocols, with a strong focus on high concurrency, performance and low memory usage.

What is the Best Usage of Ngins Server?
Nginx can deploy dynamic HTTP content on a network using FastCGI, SCGI handlers for scripts, WSGI application servers or Phusion Passenger module, and it can serve as a software load balancer.

What’s the Difference between Apache Web Server and Nginx?
Nginx uses an asynchronous event-driven approach to handling requests, instead of the Apache HTTP Server model that defaults to a threaded or process-oriented approach. Nginx's event-driven approach can provide more predictable performance under high loads.

Describe Some Best Features of Nginx?
Simultaneous Connections with low memory, Auto Indexing, Load Balancing, Reverse Proxy with Caching, Fault Tolerance

What is the Configuration File for Nginx and where it can be in UNIX like Systems?
Configuration file is named nginx.conf and placed in the directory;
 /usr/local/nginx/conf, /etc/nginx     or
/usr/local/etc/nginx          depends on distribution.

What is the Master and Worker Processes in Nginx Server?
The main purpose of the master process is to read and evaluate configuration, and maintain worker processes. Worker processes do actual processing of requests.

How to define Worker Processes?
The number of worker processes is defined in the configuration file and may be fixed for a given configuration or automatically adjusted to the number of available CPU cores

Where the Process ID does for Nginx Server is written? 
The process ID of the master process is written to the file /usr/local/nginx/logs/nginx.pid

What are the controls used in Nginx Server?
There are only few controls that are assosiated with Nginx Server and these are as below;
Nginx -s [stop | quit | reopen | reload]

How to reload configuration file of Nginx Server?
You can reload Nginx configuration file by running this command: nginx -s reload

How to reopening the log files in Nginx Server?
You can use nginx –s reopen

What is the purpose of –s with Nginx Server?
-s parameter is used to run the executable file of nginx.

How to add Modules in Nginx Server?
Nginx modules must be selected during compile, run-time selection of modules is not currently supported.

Define some of Nginx Architerture?
Here is brief nginx's architecture in diagram;

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