What are the limits of Nginx and what could they be…

Limits are used to control resources and protect against overloads. They are related to Nginx settings, the operating system, and hardware limitations.

Main types of limits:

Connection limits: Limit the number of simultaneously open connections.
Request limits: Limit the request processing rate.
Resource limits: Limit CPU, memory, and disk usage.

Configuration examples:

Limiting the number of connections:

worker_connections 1024; // Maximum number of connections per worker process

Limiting request rate:

http {
    server {
        location /rate_limited {
            limit_req zone=mylimit burst=5; // Limit 1 request per second, buffer of 5 requests
        }
    }
    limit_req_zone $binary_remote_addr zone=mylimit:10m rate=1r/s; // Define the rate limiting zone
}

Limiting request body size:

http {
    client_max_body_size 1m; // Maximum request body size of 1MB
}

Relation to the operating system and hardware:

FILE DESCRIPTORS: Nginx uses file descriptors for each connection. OS has a limit on their number.
```
# View current limit
ulimit -n
# Increase limit (for current session)
ulimit -n 65535
```
CPU/Memory: The total amount of resources affects Nginx performance and the maximum achievable limits.
Network: Network bandwidth and TCP/IP settings influence the number and speed of connections.

Factors influencing the choice of limits:

Expected load: Number of users, type of traffic (static/dynamic).
Server resources: Available CPU, memory, disk, network bandwidth.
Application type: Requirements for request processing speed, data size.
Security goals: Protection against DDoS attacks and overloads.

It is important to test the configuration under load to determine optimal limit values.

What are the limits of Nginx and what could they be related to?