Beginner's Guide by NGINX

What is the purpose of NGINX's master process?
The purpose of NGINX's master process is to read and evaluate configuration, and maintain worker processes.

What is the purpose of NGINX's worker processes?
The purpose of NGINX's worker processes is to actually process requests.

What techniques does NGINX employ to distribute requests among the worker processes?
To distribute requests among the worker processes, NGINX employs event-based model and OS-dependent mechanisms.

What's the number of worker processes NGINX starts?
The number of worker processes NGINX starts can either be defined in the configuration file or automatically adjusted to the number of CPU cores.

What are the three directories NGINX's configuration file, nginx.conf, can be placed by default?
The three directories NGINX's configuration file, nginx.conf, can be placed by default are:

1. /usr/local/nginx/conf.
2. /etc/nginx.
3. /usr/local/etc/nginx.

What signals are available to send to NGINX with the nginx executable?
The signals available to send to NGINX with the nginx executable are:

• stop - Fast shutdown.
• quit - Graceful shutdown.
• reload - Reload the configuration.
• reopen - Reopen the log files.

What does NGINX do when it receives a signal to reload the configuration?
Once NGINX receives a signal to reload the configuration, it checks the syntax validity of the new configuration and tries to apply it.

What does NGINX's master process do when the reloaded configuration is valid?
If the reloaded configuration is valid, NGINX's master process starts new worker processes and sends messages to old worker processes to shutdown.

What does NGINX's master process do when the reloaded configuration is invalid?
If the reloaded configuration is invalid, NGINX's master process rolls back the changes and continues with the old configuration.

Where can you find the PID of NGINX's master process in the file system?
You can find the PID of NGINX's master process in the file system by reading the nginx.pid file, which is either in the /usr/local/nginx/logs or /var/run directories.

How can you find the PID of NGINX's master process with the ps utility?
To find the PID of NGINX's master process with the ps utility, run:

ps -ax | grep nginx

What are the two types of directives in NGINX's configuration file?
The two types of directives in NGINX's configuration file are:

1. Simple directives.
2. Block directives.

In NGINX's configuration file, what does a simple directive consist of?
In NGINX's configuration file, a simple directive consists of a name and parameters separated by spaces, and ends with a semicolon.

In NGINX's configuration file, what does a block directive consist of?
In NGINX's configuration file, a block directive consists of the same structure as a simple directive but it ends with a set of additional instructions surrounded by braces instead of a semicolon.

In NGINX's configuration file, what is a block directive that can have other directives inside braces called?
In NGINX's configuration file, a block directive that can have other directives inside braces is called a context.

In NGINX's configuration file, what context are directives in if they're placed outside any context?
If directives are placed outside any context in NGINX's configuration file, they're in the main context.

In NGINX's configuration file, what context do the events and http directives reside?
In NGINX's configuration file, the events and http directives reside in the main context.

In NGINX's configuration file, what context do the server directives reside?
In NGINX's configuration file, the server directives reside in the http context.

In NGINX's configuration file, what context do the location directives reside?
In NGINX's configuration file, the location directives reside in the server context.

What does NGINX do if multiple location directives match the URI?
If multiple location directives match the URI, NGINX prefers the one with the longest prefix.

What does NGINX do if a location directive with a regular expression matches the URI?
If a location directive with a regular expression matches the URI, NGINX prefers it over the location directive with the longest matching prefix.

What are the two locations that NGINX logs could be stored at?
The two locations that NGINX logs could be stored at are:

1. /usr/local/nginx/logs.
2. /var/log/nginx.

What NGINX directive and parameters are used to pass a request to another server?
The NGINX proxy_pass directive, along with the protocol, name, and port of the proxied server, are used to pass a request to another server.

How do you write a regular expression which matches URIs ending with particular file extensions?
To write a regular expression which matches URIs ending with particular file extensions, write:

location ~ \.(extension1|extension2)$ {
	...
}

What directives are used to set parameters that are passed to the FastCGI server?
The directives used to set parameters that are passed to the FastCGI server are fastcgi_param directives.