101–110 of 117 posts
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I think gates change when planes need to be re-routed.
That’s the exception and not the rule and when it changes it’s typically just around the corner and you can do show infos on the old gate.
I struggle a little to see how there is a single point of failure here (a fibre optic cable). I’d have thought the screens were powered by a device plugged into a LAN. Would be interested if anyone knows the architecture of such screens and why there is such a single point of failure in the whole airport.
These screens build information from multiple sources inc. airlines, ground control, and in some cases airport management. They're typically run off-site at a data center since that provides high resiliency and some data is sourced from outside the airport anyway. If the airport has a dedicated fiber channel between their data center and airport itself and it was damaged, this could be the result. The question I'd as…
Seems like a pretty big success to me. They had a contingency plan and it was implemented successfully. No cancelled flights and minimal delays - good job.
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Some years ago, we lost access to our data center although it had triple network redundancy. What happened was that three cables were leaving the DC leased by three different companies. But a mile down the road, all three different cable entered the same physical pipe. When the physical pipe was severed, all three network cables went dark. We should wait until they announced details of what happened before we decide…
If my memory serves, one requirement of high-tier datacenters is that they have redundant electric lines leaving the building from opposite sides and in opposite directions. I guess it must be the same for optic fibers. I fully agree with you on your last sentence. One should wait for a bit more than a vague declaration reported in a newspaper before giving unsolicited advice.
How many people (even tech ops profesionals), these days, know how to tell the difference? Of those that do, how many don't just keep their mouth shut because their bosses don't want to hear it?
These details are just trusted to "the cloud", instead.
Of course, the airport itself isn't a datacenter of any tier, and that "last mile" can be the biggest redundancy challenge, anyway.
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> why they have no fallback strategies They do. It's the whiteboards. Whiteboards are cheap, resilient and robust. Exactly what one wants for a backup.
It's a good overall plan C. But why does the data link itself have no fallback? An important data link should have multiple dissimilar backups.
“High availability” database measures are often less reliable than the normal, simpler approach.
Automated network failover equipment often causes more downtime than having multiple links and only failing over manually, or even depending on a single link.
Complexity is the enemy of robustness.
System failure is not just one simple category with known behaviours; different types of failures affect performance in different ways, and it’s hard to support all of them well. Just as exception-handling code is commonly the buggiest code out there, high-availability measures are commonly some of the most fragile parts out there, unintentionally causing more problems than they solve. They can be made robust, but it takes a lot of effort to do so, and frankly it’s seldom justifiable. Typically, simplicity is good. Definitely it’s easier to debug.
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It's a good overall plan C. But why does the data link itself have no fallback? An important data link should have multiple dissimilar backups.
> why does the data link itself have no fallback? It's Gatwick, not Heathrow. Whiteboards are good enough. If every airport the size of Gatwick (and busier) implemented digital fallbacks, I wouldn't be surprised if the fallbacks took out the primary system more often than external causes. (I can’t remember the last time I used those screens over my phone. In a certain sense, the screens are now a backup.) More precis…
The evidence is that whiteboards are ok, but with their location a second fibre link would not be difficult.
Yeh, whiteboard works but another more technical solution could be roll out a TV stand and hook up the TV to a laptop via HDMI and update schedule live through a shared doc (Google docs?). I mean, whatever works right...
I struggle a little to see how there is a single point of failure here (a fibre optic cable). I’d have thought the screens were powered by a device plugged into a LAN. Would be interested if anyone knows the architecture of such screens and why there is such a single point of failure in the whole airport.
Wonder why someone didn't just prop up PC's with large monitors or projectors around the airport, hooked into the WiFi to broadcast this info?
Distantly related but when I was in Europe decades ago I was at a train station where they had a massive split-flap display ( I want to say at a couple places ). I loved watching it update. Aesthetically it was so much better than big super bright screens.
What you're looking for is called a Solari Board, there's some mesmerising videos of them around, and a few places still have them!