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Note the last image of the article is not correct, if you want full redundancy you need two independent power feeds. How independent depends on your needs of co
by chx 2y ago
Note the last image of the article is not correct, if you want full redundancy you need two independent power feeds. How independent depends on your needs of course. You might just want to run it from a different circuit but the same utility power. If you've got insane needs and megabucks you can talk to the utility about being fed from two substations or at the extreme end you can get one feed from the utility and you can make your own second feed. Traditionally we did this with water turbine working from a river but today I might look into solar and perhaps molten salt.
As an example, way back then when this was a very lucrative business, we placed the servers for a premium number erotic call in an industrial park on the border of two districts in Budapest because that's where we could get two independent power feeds without running our own lines. Internet connection wise, one was a simple leased line the other was a microwave connection to very far away. Short of bombing the entire site it was fair impossible for the installation to go offline and -- for the six years I knew about it, it never did. Note the site served German callers, that's where the big bucks came from.
- okr 2y ago[flagged]
- Germanion 2y agoHuh? How did we subsidized east European erotic call centers?
- lima 2y agoBy calling them
- Germanion 2y agoThat's just wrong use of words. And weird accusations like we Germans did this on purpose like mafia
- rendall 2y agoAre you saying Germans subsidized erotic call centers by accident?
- sillysaurusx 2y agoI’m confused how we ended up here, but happy we did. Does anyone have more info on the history of German subsidization of interactive auditory erotica?
- rendall 2y agoI really think it's time we had answers from the German government on this question.
- Germanion 2y agoNo. I'm saying that German did not subsidize those at all. There is not a source I read about Germany as a country did this. I understand that German people were using those lines and made it therefore profitable but that's not what the word subsidize implies.
- rendall 2y agoLook. I understand that some Germans were not at all involved in subsidizing erotic call centers, and those innocent Germans should be left in peace. But it's not at all clear how many Germans have been subsidizing erotic call centers, nor how much the German government had a role.
- meindnoch 2y agoFun fact, Germans are also the biggest consumers of fetish porn whose production they outsource to poorer Eastern European countries.
- _ugfj 2y agoWestern Germany has produced porn even during the socialist years in Hungary.
- deleted 2y ago[deleted]
- mcfedr 2y agoPresumably that's what they are showing with two wires with different shape connectors
- adrianmonk 2y agoAnd/or the box labeled "Utility Power" is not intended to convey any specific notion of single circuits or multiple circuits nor of single substations or multiple substations. It just depicts power that in some way comes from a utility and no more. In that sense, it is not incorrect about the configuration of utility power because it doesn't say anything about that subject.
- willis936 2y agoI'm working on a facility with redundant power and my impression is that it's not insanely expensive if you have expensive machinery to protect and that diesel generators are far and away the most common and inexpensive second feed.
- michaelt 2y agoDiesel generators are great if you need a few hours of backup (assuming the generator actually starts when you call on it). But if you need enough backup capacity to survive something a multi-state, multi-day blackout [1] that probably gets expensive. You wouldn't need that for a premium erotic call processor, but a 911 call exchange might, for the portion of their workload they can't pass off to another exchange. [1] https://en.wikipedia.org/wiki/Northeast_blackout_of_2003 https://en.wikipedia.org/wiki/Northeast_blackout_of_2003
- segmondy 2y agoNatural gas generators.
- j45 2y agoLooking at multi fuel generators is worth it too depending on your setup. For example some can run gas/propane/natural gas
- willis936 2y agoYou can store about a day's worth of diesel on-site and have agreements in place to have daily refills in cases of emergencies. If you can't get gasoline within a day's drive then there's bigger problems in the world.
- progbits 2y agoIn many places going over what you can store might put you over emission quotas and you would have to shut down anyway. I'm familiar with one incident at large DC which had fuel left and could easily get more, but only had few hours before they were required to shut down by EPA.
- znpy 2y ago> for the six years I knew about it, it never did. my dude i cannot tell you how much i love these stories of non-faang, real world engineering for extreme reliability. thank you for posting that.
- chx 2y agomy fav real world engineering story is of the first commercial ISP in Hungary back then running leased lines would've been way too expensive. So what did the kids running the show did? They got wind of a central office in an older part of Budapest have excess capacity so they rented an apartment in the next building and drilled the wall :D no expensive trenching, no expensive equipment to demultiplex landlines, nothing, just a bunch of wires running straight from the CO equipment into retail modems... We had no idea what we were doing, mind you. I was already doing Linux at the time so among the few installers I was the lucky guy who got to install the Internet at a small business who wanted it to be done on a Solaris workstation. That was a fun challenge... Other installs were Trumpet Winsock. The ISP itself ran a custom linux app, you dialed in and landed on a text app or maybe it was Lynx? can't quite remember, it's been 30 years...
- deleted 2y ago[deleted]
- linsomniac 2y ago>run it from a different circuit but the same utility power. If you're going to come from a different circuit, see if you can at least pull it from a different phase, if we're talking a 120v circuit on 240v service (typical US home service). It's a small improvement, but I'd say 10%+ of the power outages I've seen have been just a single phase going out.
- deleted 2y ago[deleted]
- DrPhish 2y agoI have also seen a single phase go out (bird poop into a transformer) and having redundant PSUs on different phases saved our bacon
- dylan604 2y agoThe house I grew up in lost transformers multiple times a year from squirrels.
- hunter2_ 2y agoThe center tapped transformer that provides residential split phase 120/240 on its secondary winding connects to just 1 of the 3 grid phases on its primary winding. If that one phase goes out on the grid, both sides of the split phase service go out together. There would need to be a fault on just one side of the split, downstream of that transformer, for your suggestion to hold up. Certainly not impossible, but far less common than a "losing one phase" scenario which would typically originate upstream on the high voltage side. On a commercial 3 phase service, yes, connect redundant PSUs to separate phases, since each phase on the panel actually corresponds to each phase of the grid.
- kurthr 2y agoBut if the issue is a local breaker flip, then being on a different phase is very effective! I don't have a power outage more than once a year, but we manage to blow a breaker more than a few times a decade (vacuum + water boiler was one).
- j45 2y agoI read the graphic differently and it reads ok to me. The two different power sources are different shapes. To someone who’s setup things in datacentres, it seems pretty reasonable to see that could be 2 different circuits. Of course it should be 2 separate plugs with the 2 different shapes in them. As for batteries you can just get a UPS system that supports adding extra batteries to it.