Click here to visit Original posting
Flashback to the 1960s, when this rookie technician is responsible for servicing a telephone switch. And what a switch it is, remembers a pilot fish in the know.
“Enormous,” says fish. “The switch fills a large room and runs unattended. It’s designed for no more than eight hours total downtime over 40 years. The design is for two identical processors, each of which is itself very reliable, and each of which monitors the other and reboots it if needed.
“Sometimes there’s a hard failure. When that happens, the processor that’s still working runs diagnostics on the other one, prints its findings on the console and sends a message to maintenance headquarters.”