Server ELF appears to be down. Although we are able to remotely reach it, we are unable to reboot it. Seems like a hardware malfunction, possibly a CPU or Motherboard failure. We have notified the datacenter technicians to investigate.
UPDATE1: We have taken the server out of the rack, into our lab, to test its components one by one until we identify the faulty hardware part
UPDATE2: The broken part was the motherboard of the server. We replaced it with a new one, and the server is now back online