Challenge 1: Calculating Theoretical Maximum Connections — Solution Walkthrough

The calculation:

With worker_processes effectively at 4 (matching the 4 CPU cores, if
set to auto) and worker_connections at 1024, the theoretical maximum
number of simultaneous connections is:

  4 (worker_processes) x 1024 (worker_connections) = 4096

The other real-world limit:

Per this chapter, this theoretical number is also capped by the
operating system's own file descriptor limit (worker_rlimit_nofile,
backed by the OS's own ulimit). Even though the Nginx config allows up
to 4096 simultaneous connections, if the OS-level file descriptor
limit per process is set lower than 1024, the actual achievable number
of connections per worker — and therefore the real total — would be
capped by that OS limit instead of the number configured in Nginx.

WHY THIS WORKS AS AN ANSWER
------------------------------
This exercise checks that the worker_processes x worker_connections
formula from this chapter is understood as a calculation to actually
perform, and that the OS file-descriptor ceiling is recognized as a
second, independent limit that can override the Nginx-side numbers
entirely.