Quite. I'm old enough to remember machine uptime being a badge of honour.
However, being older and not really wiser, I look for service uptime these days. Yes we did have similar back in the day, that's why MX and the like DNS records exist.
Old school clusters were pretty esoteric but the lessons were learned (split brain n that) and that's why we still argue the toss with kiddies about why a Proxmox cluster with two nodes is fucked and why we recommend an additional "witness".
I don't care that VMware glossed over the whole two node HA cluster thing years ago with a massive bodge. They were wrong then and they are probably still wrong because that nonsense is probably still baked in.
Sorry, slight digression.
High uptime implies no patching. We all love patching.
One reason mainframes and micros are still around us, is that you can change almost everything between hardware and software without downtime.
It is also available in commercial surviving UNIXes, and as paid for feature in some Linux distros, although not to the extent that those grandparent systems are capable of.
First, you might not reload everything in memory, so it will be patched on disk but not in process.
Second, you have not tested that the system can boot to a functional system. Say you have done live patching for 5 years and never rebooted, and then you have a power loss or hardware failure/upgrade that takes the system down. When you try to bring it back up, it doesn't work. Which configuration change in the past 5 years caused that? Which backup do you use?
And, yeah, everything is hot swappable on VAX. Those machines also cost 6+ figures, and often require a service contract that includes a permanent on site tech.
Only the last generation or 2 of the highest end VAXen had any significant hot swap (VAX 9000/400 and later, which sold very poorly). The vast majority of VAX machines didn't. Even hot-swapping DSSI disks was at best iffy.
When someone whose been there talks about VAX 'high availability', they're usually talking about VAX/VMS clustering. Very cool and generally effective approach to the problem. That was one big issue with the end-game VAXen: clustering a couple of 6-figure mid-range machine was often considered a better solution than all-in on one 7- to 8-figure VAX 'mainframe'.
often require a service contract that includes a permanent on site tech.
I don't recall that being common with DEC service contracts. Most of the sites I know of that had dedicated DEC techs were either very large installs or had...other...drivers (e.g. tech had to have a TS clearance to work on the machines).
Had an accidental reboot, and it could not boot. Had redundancy, but the other server had failed silently days prior. Solved it with three way redundancy and extra monitoring. Systems fail in many ways at the same time. If you do not test it, there is a chance it wont work. Controlled failure is preferred over unknowns, like rebooting once in a while just to make sure it works.
Not sure I'm following honestly. Your primary goes down and it fails over to the secondary (which becomes the primary), but if you can't boot how do you then get another secondary ready to fail over to again when the new primary inevitably fails?
Ah, spoken with the confidence of a freshly minted qualified worker :). Anything you don’t test is a wish, not a production system. You either know that your systems work end to end because you tested periodically, or you pray they will.
How do you know the automatic failover works? How do you know the standby system works?
I’ve seen many a “qualified workers” getting sent packing because they never fully tested the prod system because they just knew everything will work, and never tested the backup systems because qualified workers do the job right the first time, no need for backup.
You patch it in memory and on disk. What you put on disk is the patch though, so when you restart, the original unpatched version is booted, and then the same live patch is applied. This is how Ksplice worked. It has the advantage that there isn't a config file in /etc to get changed out from under it, so the second problem did not apply.
Mainframes can LPAR dynamically. When you want to test if your production system will IPL cleanly, you clone your production environment to an isolated LPAR and IPL it. No impact to production and you get your test.
There were several switch failures in the 1980s / 1990s in which systems which had been upgraded in place without a full restart failed. (IIRC, one burnt down, literally.)
Engineers were uncertain as to whether or not a cold-boot restart was even possible.
You should't need mainframe for 100% (or five nines if that's fine) service uptime.
You can build that way cheaper with 2-3 proper clustered load balancer units, 2-3 application servers behind those and those using persistent storage (databases,ldap, files) which allow writing multiple nodes simultaneously.
I used to work uni that we had few services from 2012 to 2025 my retirement with zero downtime. One time my manager with tech background tried to add PBR in hurry using WebUI and did not understand cli syntax and caused close to require reboot, but I was able to fix it from cli rolling back previous config and rebooting one unit at time. Upgrading software major version up to each unit supported level wasn't hard, upgrade node it joins back cluster, upgrade another node and it joins cluster, all done. Few times I had to fix manually config for some less important test backend servers that I had forgotten to change before upgrade. No big deal. No major outages during all that 13 years time happened. Some redirecting policy and action syntax was first hard to understand and learn like GeoIP, but I was very surprised how darn reliable and nice they to use and maintain.
The LB's were (Citrix) Netscalers in clustering mode (all nodes process traffic concurrently), which allowed live update one node at time without losing any connectivity through them. That wouldn't have been possible devices in just HA mode.
We had just 2 beefy units which worked very well for us, but you can have 2-32 of them in cluster and managing thousands of servers behind them if you need that. Netscalers are FreeBSD derived where quite a bit of the TCP/IP stack was rewritten adding support many some quite odd features std FreeBSD doesn't have. Much of that is IP/ethernet multicast features, PBR's, Traffic Domains (VRF's) and of many service and monitoring processes which sync cluster (or HA) and if node fails another can continue straight from there without any loss of traffic to clients being proxied.
Though I think most people in this forum are familiar with with haproxy, pound and web-server software provided reverse proxying.
A car analogy if previous were your fancy sport sedan Netscaler and F5 BigIP are formula F1 class cars ie. quite different beasts altogether.
e: And proper LB's are not just for HTTPS etc. but very nice proxying many other protocols were they TCP, UDP or something else. We did done VPN's and something like Cisco AP'S CAPWAP (DTLS ie SSL over UDP).
e: typo.
I’ve long wanted that amazing uptime and virtualization and huge I/O and all that cool stuff mainframes offered, but on the desktop or in the closet, with modern CPUs.
In 2012 I took over a Perl project that was running on 25 BSD servers (OpenBSD I think?) that had not been updated / patched since 2000. It was an interesting time.
MX records publish an SMTP server for a domain and a 'priority'. You can have multiple MX records and (theoretically[1]) you try the one with the lowest priority, and if it doesn't respond, try the next lowest, etc. Or (theoretically[1]) if you have 2 MX records with the same priority, you can load balance between them.
The article describes the veneration Roman -> (old) Greek -> (old) Egyptian and this finding appears to show that the veneration went both ways.
Frankly I can understand that: Homer really did smash out an absolute banger with Iliad. I might ask for a copy in my grave too, when the time comes.
The whole point of the article appears to be that when civilizations overlap, the "good old days" becomes a two way street (to gargle metaphors). I do find that interpretation very interesting and it fits in with my world view that history ("historia" - Latin for "story") is generally rather more complicated than many would like it to be to fit their current (or current as was) world view.
I have a Reolink but haven't got to Home Assistant yet. I'm happy switching to that, but for less technical (though still digital savvy) spouses - how would you say the switch would be for them?
I'd say it depends on what you are trying to do. If it is simple device control and media playing and other stuff, then all you need is to update [dashboards](https://www.home-assistant.io/dashboards/) when you add/move devices and the users will find it pretty easy and straightforward. My parents are not extremely tech savvy but they find Home Assistant easy to use when I make the dashboards thoughtfully.
Making automations and scripts is getting easier every update, but it has a small learning curve as the logic can get complex and you sometimes need to know details like entity IDs or raw states. And there are some simple missing features that some people are very used to. Home Assistant is improving that sort of thing constantly, but sometimes the device APIs do not allow all functionality without the OEM apps.
For example, the two biggest camera-related things that are missing in my opinion is that the camera viewer does not allow zoom or two way talk. It uses the native browser media player, and on both a Samsung tablet and all iOS devices, this means that you cannot zoom and pan around the image. This is obviously not an issue if you embed a dashboard such as Frigate into the HA UI, which IIRC supports both two way talk and zoom. But YMMV.
Basically what they said but you can do two way talk too! For me Frigate is the way to do cameras and there is a HA addin which does take a bit of configuring but there are loads of decent docs.
Home Assistant is quite a beast but start off simple and work on. It will repay you every step of the way. The first hurdle is to get it on the internet and usable via the app. Get that sorted and you are well on your way.
Make use of dynamic DNS to register a name to IP address and Lets Encrypt to sort out a SSL cert. There are add ins for both of those.
You can also subscribe to Nabu Casa and external access and a few other things will be taken care for you. 31 day trial and https://www.nabucasa.com/pricing/
"But evolution doesn't make those developments improbable or coincidental." (not sure what you are on about with respect "Time's Second Arrow")
So, why are you not enslaved by your lizard overlords? 8) Homo is a bit of a johnny come lately and yet has managed to travel to the moon and back.
We only have a single extant example of hom sap to work with. We can work backwards, within reason, and still not manage to come up with a completely satisfying origin story. There is no way you can "derive" hom sap from first principles.
We(mammals) kind of were enslaved by those lizard overlords. Mammals evolved around 225 million years ago and by the time dinosaurs went extinct (through no fault of their own!) 160 million years later, mammals were, at best, small nocturnal mouse-sized creatures. Anything bigger was stomped out by the dinosaurs before it could leave a trace.
Around 40 years ago, I was cycling around Andover (Hants, UK). Me and a mate were whizzing around near a small artificial lake. I decided to run into what I thought was shallow water and it wasn't. With hindsight that was a really daft failure of perception but you live and learn.
Forty years later touch wood I have not yet broken myself or a car ...
Bugger Oyster and bugger CCTV! How well protected do you think all those video doorbells are?
Your comment is right minded but miss-guided.
You are right to insist on privacy but you failed to note that your neighbours are not twitching their curtains beyond noting your cat is crapping on their veg. To be fair, they probably are but those door cams are probably available in forn parts, way beyond Gladys at no 9's wildest dreams.
I'm old enough to remember Badgers flying across the UK! Those are fucking huge Russian four engined plodders, wheezing across at high altitude in an attempt to cow us into ... some sort of submission. Invariably a flight of Phantoms or Starfighters would whizz on up. In the good old days we'd strap a decent chap onto a firework called a Lightning. I did see a pair do that job - spectacular and I'm sure the pilots probably ended up swallowing their teeth.
Russia does steam punk in some bloody odd ways.
Anyway, I would avoid worrying about our state watching you and worry about other states instead.
Quite. I'm old enough to remember machine uptime being a badge of honour.
However, being older and not really wiser, I look for service uptime these days. Yes we did have similar back in the day, that's why MX and the like DNS records exist.
Old school clusters were pretty esoteric but the lessons were learned (split brain n that) and that's why we still argue the toss with kiddies about why a Proxmox cluster with two nodes is fucked and why we recommend an additional "witness".
I don't care that VMware glossed over the whole two node HA cluster thing years ago with a massive bodge. They were wrong then and they are probably still wrong because that nonsense is probably still baked in.
Sorry, slight digression.
High uptime implies no patching. We all love patching.
reply