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teromon I designed a cube that balances itself on a corner

It will take a bit more engineering than some optimistic sign-flipping to bring it down to $50 retail (~$10 BOM).

> In my case, the BOM was close to €2500, so be prepared for that.

EDIT: someone pointed out that there are actually some designs available on AliExpress, e.g. https://a.aliexpress.com/_EzMRNIv €250 for one axis (edge) and €500 for a 3-axis (single point).

teromon Ask HN: Should I try to manufacture toasters?

https://www.mouser.fi/ProductDetail/Diodes-Incorporated/PT8A...

Now I want to buy a couple... 0.856 € unit price for 1pcs, available in stock.

New evil plan: corner the market on toaster controller ICs and build up a strategic reserve to resell to manufacturers at inflated prices.

teromon Ask HN: Should I try to manufacture toasters?

https://photos.app.goo.gl/S6sFaEUxY89Tgxn56 here's an example of the safety/certification markings from a 24V power supply sold in the EU.

Take a close look at the TÜV/GS logo and font. I seriously doubt the UL file number E131992 exists. The Safety Mark 021068-00 code is for a Samsung AC Adapter [1], which this is not. You can see some of the same details in the AliExpress listings.

[1] https://www.go.gov.sg/safety-mark

teromon Ask HN: Does Cloudflare block HN comments if you have code blocks in a reply?

Easy: just set up the WAF but with an empty ruleset.

teromon Philips recalls 340 MRI machines because they may explode in an emergency

> There has been one reported event of an explosion in 22 years of use. There have been no reports of injury or death.

teromon My cat water fountain comes with a spicy USB power adapter

It is indeed very regional, e.g. the UK has its own thing going on with ring mains and fused plugs.

Over in my 230V corner of the EU, CEE 7/3 sockets are pretty much the only thing I'm aware of for new wiring, with the unearthed CEE 7/1 sockets still present in older installations. Both are rated for 16A, with either 10A/1.5mm² or 16A/2.5mm² branch circuits from the distribution board. It would be unheard of to wire those up with any higher ampacity at risk of overloading the sockets - although recent experience with e.g. EVs has shown that they're not actually suitable for sustained loads at 16A, given e.g. wear and tear on the sockets.

Unearthed appliances do commonly have CEE 7/16 plugs rated for 2.5A, particularly things like wall warts or USB chargers, which does fit into a CEE 7/3 socket.

I recall seeing CEE 7/16 (2.5A europlug) sockets, although those may have been imports from elsewhere in the EU. I suppose those would have the same issues if wired up to the same distribution circuits. But extension cables for those are rarer, the only ones I've ever seen are CEE 7/7 plug (16A) -> CEE 7/16 sockets (2.5A).

For residential/commercial loads over 16A / 3.2kW, it's all CEE / IEC 60309 connectors, and those are treated like distribution circuits with overload protection sized appropriately for the connectors/cables.

teromon My cat water fountain comes with a spicy USB power adapter

Yeah, the risks mainly come with extension cords, like plugging a bunch of 10A appliances into a single 20A outlet via a 10A rated extension cord with multiple 10A outlets.

Appliances themselves with their own input fuses and captive cables are less risky, although some kind of internal wiring short could still get all melty.

It's true that sizing the plugs that way does prevent you from plugging a 20A appliance into a 10A extension cord, which makes sense.

teromon My cat water fountain comes with a spicy USB power adapter

> But a 10 amp plug can still fit and sit snugly in a 15 or 20 amp socket, and a 15 amp can still fit into a 20 amp socket with no problems. It’s pretty clever.

That sound dangerous. The larger fuse sized for the 20A socket will not protect the smaller conductors in the cable sized for the 10A plug, they can get overloaded.

The three-phase / industrial CEE plugs and sockets used in the EU are sized for 16A/32A/63A/125A. It's perfectly legal and safe to make a passive adapter that lets you plug a 32A appliance or distribution box into a 16A socket, you just can't load it higher than the 16A fuses on the socket. Going the other way around (16A plug into a 32A socket) you MUST have a circuit breaker in between to provide the required overload protection.

teromon Kubernetes Needs an LTS

Bridges need regular maintenance or they will fail and come crashing down.

teromon Bidding error sees Finnish day-ahead power price tumble

https://www.fingrid.fi/sahkomarkkinat/sahkojarjestelman-tila... shows a roughly +1GW (~12GW -> 13GW) rise in consumed power during the first two hours after the price hitting the negative pricing floor (-500€/MWh) at 15:00. Seems like there's some consumer elasticity there, but not enough to make the grid fall over.

This is after the national grid operator planned to intervene as necessary and imposed some restrictions on trading [1], but those seem to have been lifted and the intra-day market is working (at 10× normal volumes).

> Fingrid is prepared to initiate Intraday purchases, if necessary, to ensure system security and balancing capacities concerning the non-matching situation in the Finland bidding zone after Day-ahead trades.

> Update 24.11.2023 12.:12 Market situation has normalized due to Intra day trading. Fingrid resumes normal operations. Fingrid asks BRP to manage their balance normally.

> Fingrid has closed intraday trade in directions FI>SE1 and FI>SE3 to ensure system security and balancing capacities concerning the non-matching situation in the Finland bidding zone after Day-ahead trades.

> Update: Intraday trade in direction FI>EE closed

> Update 24.11.2023 12:25 Intraday trade is open to all directions

[1] https://umm.nordpoolgroup.com/#/messages?publicationDate=all...

teromon Bidding error sees Finnish day-ahead power price tumble

> There are some things markets are very good at. This is one of them.

Ironic in a thread about the market making up a totally imaginary generation surplus.

10-20% of Finnish retail customers are on spot market based contract, and stand to save up to something on the order of 0.40€/kWh consumed (net after taxes and fees) off their electrical bill for the reminder of the day. I suppose every market-rational consumer would have a 10kW electric space heater outside melting snow on the ground, maxing out their supply.

teromon Tested: Black 4.0, the "blackest black" is a lot blacker. 0f1012 vs. 272928

I'm guessing the paint is very fragile, and it wouldn't survive any wear and tear.

> This show car is destined to remain a one-off because of the enormous difficulty involved in making Vantablack paint suitably durable for everyday automotive use. The car paint needed for the world’s blackest black would also be extremely expensive, not to mention questionable in terms of road safety due to its level on the absorption spectrum.

teromon Therapy centre hack suspect faces aggravated blackmail, other charges

Additional context from HS: https://www.hs.fi/kotimaa/art-2000009931214.html

The suspect is accused of stealing tens of thousands of sensitive psychotherapy patient records from a MySQL server exposed to the public internet, using what I presume to be a weak MySQL (root) password.

The suspect is then accused of ransoming first the private healthcare provider, and then the individual patients (using the stolen email addresses). The ransomer went public and started leaking the patient records in batches of 100, before prematurely leaking the entire set by accident. The records contained what I believe included full detailed records from the individual psychotherapy sessions.

The company was aware of the breach, but did not report it before the attacker went public. There was, if I recall correctly, some kind of crypto locker compromise that brought their systems down, but those were only reported as some form of technical maintenance gone wrong.

Harder to find a source for it because the older articles are paywalled, but the IT employees responsible for the systems were not charged, instead the CEO was convincted of some form of criminal negligence. Plus financial fraud for selling the business without disclosing the earlier breach.

teromon AWS IPv4 Estate Now Worth $4.5B

No, 192.168.1.110 is MY network printer, you must have gotten confused somewhere!

teromon iPhone 15 and iPhone 15 Plus

For USB C-C cables PD and passive 5V (5K1 pulldown) is negotiated over a separate CC pin from the USB2 D+/- pins, so it's theoretically possible if the D+/- lines are not connected/damaged.

USB A-C cables are entirely separate, there is no CC line, only a fixed always-on Vcc pin at 5V.

teromon UK Air traffic control network crash

System redundancy rarely covers software faults.

teromon Texas electricity prices soar 6k% as heat wave is expected to shatter records

In the Finnish market the situation changed drastically during 2022-2023 as the energy market futures went through the roof and fixed-price contracts became crazy expensive (10-20× "normal" kWh prices). I'm not sure if there are any official public statistics, but a recent news article [1] puts eg. 30% of consumers on spot price contracts, and during the spring they were the vast majority (70%) of new contracts.

The news media reporting is mostly about the people locked into two-year 30-60c/kWh contracts, and not the people paying the recent <3c/kWh spot price averages.

Recently [2] a combination of several simultaneous planned/unplanned outages and low wind power generation have bumped the spot market prices back up again, so let's see.

[1] https://www.aamulehti.fi/talous/art-2000009773460.html [2] https://www.fingrid.fi/ajankohtaista/tiedotteet/2023/monet-y...

teromon What happens when you COPY in Postgres?

The way that the "Postgres", "libpq" terminology is used in the article ("libpq, the API backend for Postgres") leaves me more confused than I was before. I would understand "libpq" as the client-side library implementing the PostgreSQL wire protocol, and "Postgres" as the PostgreSQL server implementation, but I think in this article "Postgres" seems to refer to the psql CLI implementation?

> I’d like to dig more into how a C FILE reference is created on the server to utilize the above code. I plan to also do more more digging on the libpq side of this operation, including how the data is written to the WAL and processed

I don't think libpq has anything to do with WAL processing, and I would likely guess that the PostgreSQL server implementation actually uses mmap?

teromon MS Teams channels cannot contain MS-DOS device names

The 5² limit seems small, but at least you can have 500,000³ teams in Microsoft 365 Office organization - 1.25E17 should be plenty, that's around 15M teams per person on the planet;)

Perhaps they should rethink the use of numbered superscripts for notes in that table....

teromon Zenbleed

That sounds like it's leaking across user/process boundaries on a single EC2 instance, which presumably also requires the processes to be running on the same core.

Leaks between different EC2 instances would be far more serious, but I suppose that wouldn't happen unless two tenants / EC2 instances shared SMT cores, or the contents of the microarchitectural register file was persisted across VM context switches in an exploitable manner.

teromon OpenTTD's Infrastructure in 2023

I think it would be a very bad idea to host the entire OpenTTD infrastructure on your MacBook Pro.

teromon Space After Periods (1993)

  >>> 1, 2
    File "<stdin>", line 1
      1, 2
         ^
  SyntaxError: invalid character in identifier

The reason for `xbd_options nbsp:none`...

teromon Hunting for Nginx alias traversals in the wild

HAProxy does not serve static files, so it's a poor alternative for this specific case.

teromon Github.com is down

It's more a question of which of the (tens of) thousands of various different healthcheck pings that GitHub has undoubtedly implemented across their infrastructure should be used to determine the status page status?

teromon Logs Told Us It Was DNS, It Looked Like DNS, It Had to Be DNS, It Wasn't DNS

The exciting opportunities of getting to debug issues like this makes complex Kubernetes/microservice setups very appealing!

teromon Datadog’s $5M Outage

TLDR: Ubuntu unattended-upgrades and the systemd-networkd `ManageForeignRoutes=true` [1] default broke all Kubernetes networking globally, across multiple regions and cloud providers simultaneously, at 06:xx UTC. Recovery was difficult and slow due to the scale, particularly with cloud auto-scaling behavior kinda making things worse when all nodes failed simultaneously.

Please test how `systemctl restart systemd-networkd` affects your custom networking setup. It is quite likely to break.

DataDog also published their own post-mortem: [2]

[1] https://www.freedesktop.org/software/systemd/man/networkd.co...

[2] https://www.datadoghq.com/blog/2023-03-08-multiregion-infras...

teromon Slack issues

Digging into the status page history reveals a reference to an issue lasting for 7 minutes, caused by a "minor technical change" that was rolled back. [1]

Still claims 100% uptime for May.

https://status.slack.com/2023-05-17

teromon Scaling up the Prime Video audio/video monitoring service and reducing costs

> The second cost problem we discovered was about the way we were passing video frames (images) around different components. To reduce computationally expensive video conversion jobs, we built a microservice that splits videos into frames and temporarily uploads images to an Amazon Simple Storage Service (Amazon S3) bucket. Defect detectors (where each of them also runs as a separate microservice) then download images and processed it concurrently using AWS Lambda. However, the high number of Tier-1 calls to the S3 bucket was expensive.

Taking "malloc for the Internet" [1] a bit /too/ literally there.

[1] https://aws.amazon.com/blogs/aws/eight-years-and-counting-of...

teromon Sensenmann: Code Deletion at Scale

It's about time someone gets a KPI for lines of code removed :)