You need multiple physical links in running to different ISPs because builders working on properties further down the street could accidentally cut through your fibre. Or the ISP themselves could suffer an outage.
You need a back up generator and to be a short distance away from a petrol station so you can refuel quickly and regularly when suffering from longer durations of power outages. You absolutely do not want to run out of diesel!
You need redundancy of every piece of hardware AND you need to test that failover works as expected because the last thing you need is a core switch to fail and traffic not to route over secondary core switch like expected.
You need your multiple air con units and them to be powered off different mains inputs so if the electrics fail on one unit it doesn’t take out the others. I guarantee you that if the air cons will fail, it will be on the hottest day of the year a month amount of portable units will stop your servers from overheating.
You need beefy UPS with multiple batteries. Ideally multiple UPSs with each UPS powering a different rail on your racks so that if one UPS fails your hardware is still powered from the other rail. And you need to regularly check the battery status and loads on the UPS. Remember that the back up generator takes a second or two to kick in so you need something to keep the power to the servers and networking hardware to be uninterrupted. And since all your hardware is powered via the UPS, if that dies you still lose power even if the building is powered.
And you then need to duplicate all of the above in second location just in case the first location still goes down.
By the way, all of the possible failure points I’ve raised above HAVE failed on me when managing HA on prem.
The reason people move to the cloud for HA is because rolling your own is like rolling your own encryption: it’s hard, error prone, expensive, and even when you have the right people on the team there’s still a good chance you’ll fuck it up. AWS, for all its faults, does make this side of the job easier.
In fact I used to run some hobby projects in OVH (as an aside, I really liked their services) so I’m aware that they have their own failures too.
The Azure outage was just AD service but you can roll your own there if you wanted.
Plus if you want to talk about SaaS then OVH et al have their own SaaS too. In fact the difference between OVH and AWS is more about scale than it is about reliability (with AWS you can buy hardware and rack it in AWS just like with OVH too).
Or maybe by “old skool” you mean the few independent hosts that don’t offer SaaS. However they’re usually pretty small fry and this outages are less likely to be reported. Whereas any AWS service going down is massive news.
I’m not a cloud-fanboy by any means (I actually find AWS the least enjoyable to manage from a purely superficial perspective) but I’ve worked across a number of different hosting providers as well as building out HA systems on prem and the anti-cloud sentiment here really misses the pragmatic reality of things.
I would also argue many aren't even using multiple availability zones, as evidenced by the wide array of problems on the internet when a single AZ goes down.
I think you're vastly over-estimating how most companies are using AWS, and are substituting your own requirements for theirs.
Which is very common in tech. It's part of why people shit on cloud, microservices, and other techniques large mega-corps use on HN. People write posts with lots of assumptions and few details, then people that don't know any better just carbon copy it because hey its what Google does. Meanwhile their lambda microservice system serving a blazing 60 requests per minute has more downtime than if I just hosted it on my laptop with my dialup internet connection.
Hence why I compare doing HA in AWS correctly vs doing HA on prem correctly.
Yes, Hetzner upgrades DCs (datacenter buildings), but they are the equivalent to AWS AZs (Availability Zones). When they upgrade a DC, they notify way in advance, and if you set up your services to span multiple DCs as is recommended, it does not affect you.
We run high-availability Ceph, Postgres, and Consul, across 3 Hetzner DCs, and have not had a Hetzner-induced service downtime in the 5 years that we do so.
Colo space assumes that the colo is operating more efficiently than AWS/Azure/GCP when in reality you’re comparing apples and oranges.
financial services, telecom and high-precision manufacturing companies
What use does a CNC shop have for an extensive on-prem multi-DC with failover and high availability? It'd be like buying your own snowplows to make sure that the road is clear so your employees can get to work. Maybe necessary if you live in a place with very bad snowplows and no existing infrastructure, but in most places, just a waste of money.
Also the reasons those companies usually run their own infra is historically down to legislation more than preference. At least that’s been the case with almost all of the companies I’ve built on prem HA systems for.
At my last job we provided redundant paths (including entry to your building) as an add-on service. So you might not need two ISPs if you're only worried about fiber cuts. You could still be worried about things like "we think all Juniper routers in the world will die at the exact same instant", in which case you need to make sure you pick an ISP that uses Cisco equipment. And of course, it's possible that your ISP pushes a bad route and breaks the entirety of their link to the rest of the Internet.
I don't see why the petrol station needs to be a short distance away. Unless the plan is to walk to the petrol station and back (which should not be the plan[1]), anyplace within reasonable driving distance should do.
[1] long duration electrical outages will often take out everything a short distance away, and the petrol stations usually have electric pumps.
Also buying fuel for a petrol station is going to be more expensive than having a commercial tanker refill it. So ideally you wouldn’t be making large top ups from the local petrol station except under exceptional outages.
As for wider power outages affecting the fuel pumps, I suspect they might have their own generators too. But even if they don’t, outages can still be localised (eg road works accidentally cutting through the mains for that street - I’ve had that happen before too). So there’s still a benefit in having a petrol station near by.
To be clear, I’m not suggesting those petrol stations should be 5 minutes walking distance. Just close enough to drive there and back in under half an hour.
If you do move to an established data centre then you’re back to my earlier point that you’re still then dependant on their services instead of having ownership to fix all the problems yourself (which was the original argument the GP made in favour of switching away from the cloud).
some natural disasters can render driving trickier than walking. extremely large snow storms, for instance. you can still walk a block, but you might be hard pressed to drive 5 miles.
(i don't have a bone in this particular cautiousness-fight; personally i'd just suggest folks producing DR plans cover the relevant natural disasters for the area they live in, while balancing management desires, and a realistic assessment of their own willingness to come to work to execute a DR plan during a natural disaster.)
If you are going to the level of the above, you go with co-location in purpose built centers at a wholesale level. The "layer1" is all done to the specs you state and you don't have to worry about it.
On-prem rarely actually means physically on-prem at any scale beyond a small IT office room. It means co-locating in purpose built datacenters.
I'm sure examples exist, but the days of large corporate datacenters are pretty much long over - just inertia keeping the old ones going before they move to somewhere like Equinix or DRT. With the wholesalers you can basically design things to spec, and they build out 10ksqft 2MW critical load room for you a few months later.
A few organizations will find it worthwhile to continue to build at this scale (e.g. Visa, the government) but it's exceptionally small.
Then you’re not running HA and thus the argument about cloud downtime being “worse” than on prem is moot.
Obviously if your SLA is basically “we will do our best” then there are all sorts of short cuts one can take. ;)
30 years ago when you talked on-prem that's what this meant. It's now shifted to on-prem meaning your own hardware in massive shared facilities that handle all that "hard stuff" like redundant power and cooling for you.
Bespoke datacenter builds for true-on prem certainly exist, but it's not what that term typically means any longer - at least in my line of business. When I'm selling racks of colo now, my customers are calling that their on-prem facilities.
In fact a large part of my previous business was dismantling true "on-prem" facilities to move to such large shared wholesalers.
My building has a natural gas backup generator.
I’ve never seen a data center with natural gas backup power. But I don't know if that's because of reliability or if it's too expensive for a big natural gas hookup that's used rarely. Though I have heard of the opposite -- using natural gas turbines as primary power and utility power as backup.
If you're outsourcing that, you'd likely have to pay a boatload just for someone to be available for help, let alone the actual tasks themselves. Like you said, if you're on-prem and something goes down, you can do something. But you've gotta have the personnel to actually do something.
That said, I think you're spot-on as long as you have the skillset already.
I hear this argument a lot, but every startup I've been involved with had a full-time DevOps engineer wrangling Terraform & YAML files - that same engineer can be assigned to manage the bare-metal infrastructure.
Bare metal infrastructure requires a lot more management at any given scale. I mean, you can run stuff that lets you do part of the management the same as cloud resources, but you also have to then manage that software and manage the hardware.
Obviously depends on what you need, but for a small to medium web app that needs a load-balancer, a few app servers, a database and a cache, yes absolutely - all of these have been solved problems for over a decade and aren't rocket science to install & maintain.
> Is it worth it?
I'd argue that the "worth" would be less about immunity to occasional outages but the continuous savings when it comes to price per performance & not having to pay for bandwidth.
> overestimate how important it is for their services to run uninterrupted.
Agreed. However when running on-prem, should your service go down and you need it back up, you can do something about it. With the cloud, you have no choice but to wait.