What can lead to exhaustion of file descriptors in a system?

File descriptor exhaustion in the system occurs when a process or the entire system opens too many files or other resources requiring descriptors, reaching the limit set by the operating system.

Main causes:

• Programs open files, sockets, or other resources and do not close them (descriptor leaks).
• Simultaneous opening of a large number of files or network connections.
• Low system limits on the number of open files (ulimit in Unix-like systems).

To avoid this problem, it is necessary to monitor proper closing of files and resources, and increase descriptor limits if necessary.