Function maximize_fd_limit 

pub fn maximize_fd_limit() -> Result

Raises the soft file descriptor limit to the current hard limit.

RocksDB and concurrent federation connections can exceed the common soft limit of 1,024 during startup. Systemd commonly provides a hard limit of 524,288.

• https://www.freedesktop.org/software/systemd/man/systemd.exec.html#id-1.12.2.1.17.6
• https://github.com/systemd/systemd/commit/0abf94923b4a95a7d89bc526efc84e7ca2b71741