When you think about it, 24 years is not such a long time for a machine to keep doing what it's supposed to be doing. It says something about our profession that we find a 24-year service life surprising.

There are airliners that have been in service for over 50 years.

▲

VectorLock 30 minutes ago | parent | next [-]

>There are airliners that have been in service for over 50 years.

Are there any airliners that have flown for 24 years non-stop?

	▲	serf 16 minutes ago \| parent \| next [-]
		this is why I find comparing mostly-solid-state stuff with big mechanical contraptions a frustrating exercise. it's more impressive to me that the electric fans within the Stratus server still operate than it is that the chips still work, and if we're going with the plane metaphor it's the silicon that puts the thing into the air, not the simple fans. So really it just boils down to "well, the planes work is harder." as to why it fails, which is of course abstract and unsatisfying; comparing the comparative lifetime workloads of a chip that has shifted trillions of bits versus some jet engines that have moved millions of kilograms around the world. and then another layer comes and makes it even weirder : the vast majority of hardware around the world that has been EoLd and replaced has been in that situation due to software, not the hardware itself; a paradigm that really doesn't exist in the physical engineering world in the same was as it does CS.
	▲	dlisboa 14 minutes ago \| parent \| prev \| next [-]
		Yeah, it’s not a good comparison. Give me endless parts and a maintenance window of 6 months every so often and I can make any server last a century.
	▲	russianGuy83829 24 minutes ago \| parent \| prev [-]
		That would not be a useful airliner.

▲

tyrabound 2 hours ago | parent | prev | next [-]

You raised in my mind that we are looking at this all wrong, the server is not actually one component, it’s really a system of systems, and just like an airliner is a system of systems too, the conflict arises in that the comparison is at the wrong level.

It seems when people think of a server today, they think of a single computer, if not some software server somewhere in the cloud. These subject kinds of servers are far closer to complex systems of separate components, more like a network system, it’s why components of what are really separate networked computers can and need to be replaced.

An airliner is of course also made up of components that are also systems, however at least in my mind, the difference is the actual expected use case. An airliner is not a good comparison because it is never expected to remain in continuous operation, e.g., that at least one engine is always running even when it is being overhauled or repaired, to satisfy a requirement of continuous operation.

▲

pitched an hour ago | parent [-]

FTA, this is a fault-tolerant server where all hardware is redundant and can be hot swapped while running. The servers you’re thinking about are redundant at the software level so rebooting one server won’t cause the service to go down.

What is remarkable is that apparently that VOS thing has never crashed. I wonder if they also do software redundancy under the hood to keep uptime going during reboots. If the CPU is hotswappable, it must have something.

	▲	wildzzz 18 minutes ago \| parent \| next [-]
		Probably uses formally verified code along with plenty of housekeeping processes to keep any failures from shitting the whole bed. In critical system design, you build in redundancies that work in parallel such that any one failure will not interrupt the system. The main computer system in the Space Shuttle is an excellent example of this. It had 5 identical IBM System/4 Pi machines. Three of them ran identical code and handled the same work. The fourth ran a completely different codebase to handle the same work, preventing a bug in the main code from killing the whole system. A fifth computer handled other tasks but could be swapped over to the critical role if needed. You could lose 2/5 computers and still have insurance against a cosmic ray flipping a bit.
	▲	serf 13 minutes ago \| parent \| prev [-]
		VOS is a parallel lockstep OS. You drop nodes and replace them to keep the whole operational.

▲

asah 3 hours ago | parent | prev | next [-]

yabut... airliners require constant maintenance and periodic rebuilds.

	▲	andrew_lettuce 2 hours ago \| parent \| next [-]
		Not to mention service disruptions and unplanned downtime.
	▲	bitwize an hour ago \| parent \| prev \| next [-]
		One of the major differences between like, your PC, and a high-availability server is that high-availability servers require those things as well—and get them, piecewise, while still running. It's like doing a complete overhaul while the plane is flying. IBM mainframes, famously, phone home if they detect a faulty component. Service personnel will be on site, same day, to replace it before you even knew it was there, let alone had the opportunity to ask.
	▲	an hour ago \| parent \| prev [-]
		[deleted]

▲

lp92 2 hours ago | parent | prev | next [-]

Those aircraft have maintainance windows/refurbishment/refits and aren't flying 24/7 though.

	▲	debo_ 40 minutes ago \| parent [-]
		This server also had planned downtime maintenance. The article specifically mentions "no unplanned downtime."

▲

vanviegen 3 hours ago | parent | prev | next [-]

It's not so much surprising that the machine hasn't broken, but that someone apparently considered it worthwhile to keep it around, having about the compute of a throwaway vape.

▲

afavour 3 hours ago | parent | prev | next [-]

I think it just speaks to how quickly the tech has developed. Airliners work more or less the same as they did 50 years ago, computers are vastly different (and vastly more powerful).

▲

Leonard_of_Q 2 hours ago | parent [-]

Airliners may look the same but they don't work as they did 50 years ago when the was no fly by wire in these planes, no high-bypass engines, etc.

	▲	yCombLinks 23 minutes ago \| parent [-]
		Computers are many thousands of times faster and more efficient than they were 50 years ago. Airplanes still fly at the same speeds, and with only marginal safety improvements. Fuel efficiency has doubled however. Overall significantly less changes.

▲

Transformanshen 2 hours ago | parent | prev | next [-]

That may well be the case, but such a long period still seems extraordinary

▲

streetfighter64 3 hours ago | parent | prev | next [-]

Airliners are up against physical limitations that don't incentivize upgrading. If there was an airliner that could fit millions of people and cost less than the 1980s version, I don't think you'd see many 80s aircraft around anymore, except in niece applications such as this computer. Perhaps now that we're at the end of Moore's law, you might see a larger amount of long-lived computers. But on the other hand, we'll probably find new ways to innovate in computing power.

▲

wazoox 2 hours ago | parent | prev | next [-]

There are industrial machines such as steam hammers that have been in constant use for more than a century.

▲

3 hours ago | parent | prev [-]

[deleted]