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Shutting Down Clear Linux OS

https://community.clearlinux.org/t/all-good-things-come-to-an-end-shutting-down-clear-linux-os/10716
34•todsacerdoti•49m ago•15 comments

Asynchrony is not concurrency

https://kristoff.it/blog/asynchrony-is-not-concurrency/
155•kristoff_it•5h ago•107 comments

How to write Rust in the Linux kernel: part 3

https://lwn.net/SubscriberLink/1026694/3413f4b43c862629/
33•chmaynard•2h ago•0 comments

Ccusage: A CLI tool for analyzing Claude Code usage from local JSONL files

https://github.com/ryoppippi/ccusage
17•kristianp•1h ago•6 comments

Silence Is a Commons by Ivan Illich (1983)

http://www.davidtinapple.com/illich/1983_silence_commons.html
61•entaloneralie•3h ago•10 comments

Wii U SDBoot1 Exploit “paid the beak”

https://consolebytes.com/wii-u-sdboot1-exploit-paid-the-beak/
70•sjuut•4h ago•8 comments

Broadcom to discontinue free Bitnami Helm charts

https://github.com/bitnami/charts/issues/35164
84•mmoogle•5h ago•49 comments

Multiplatform Matrix Multiplication Kernels

https://burn.dev/blog/sota-multiplatform-matmul/
48•homarp•4h ago•16 comments

Valve confirms credit card companies pressured it to delist certain adult games

https://www.pcgamer.com/software/platforms/valve-confirms-credit-card-companies-pressured-it-to-delist-certain-adult-games-from-steam/
155•freedomben•8h ago•154 comments

lsr: ls with io_uring

https://rockorager.dev/log/lsr-ls-but-with-io-uring/
295•mpweiher•11h ago•151 comments

Meta says it wont sign Europe AI agreement, calling it growth stunting overreach

https://www.cnbc.com/2025/07/18/meta-europe-ai-code.html
92•rntn•6h ago•126 comments

EPA says it will eliminate its scientific reseach arm

https://www.nytimes.com/2025/07/18/climate/epa-firings-scientific-research.html
74•anigbrowl•1h ago•46 comments

Trying Guix: A Nixer's impressions

https://tazj.in/blog/trying-guix
134•todsacerdoti•3d ago•38 comments

AI capex is so big that it's affecting economic statistics

https://paulkedrosky.com/honey-ai-capex-ate-the-economy/
186•throw0101c•4h ago•204 comments

Replication of Quantum Factorisation Records with a VIC-20, an Abacus, and a Dog

https://eprint.iacr.org/2025/1237
58•teddyh•5h ago•16 comments

Show HN: Molab, a cloud-hosted Marimo notebook workspace

https://molab.marimo.io/notebooks
64•akshayka•5h ago•8 comments

The year of peak might and magic

https://www.filfre.net/2025/07/the-year-of-peak-might-and-magic/
72•cybersoyuz•7h ago•36 comments

Mango Health (YC W24) Is Hiring

https://www.ycombinator.com/companies/mango-health/jobs/3bjIHus-founding-engineer
1•zachgitt•5h ago

Show HN: I built library management app for those who outgrew spreadsheets

https://www.librari.io/
46•hmkoyan•5h ago•27 comments

Sage: An atomic bomb kicked off the biggest computing project in history

https://www.ibm.com/history/sage
13•rawgabbit•3d ago•1 comments

CP/M creator Gary Kildall's memoirs released as free download

https://spectrum.ieee.org/cpm-creator-gary-kildalls-memoirs-released-as-free-download
227•rbanffy•14h ago•119 comments

Cancer DNA is detectable in blood years before diagnosis

https://www.sciencenews.org/article/cancer-tumor-dna-blood-test-screening
158•bookofjoe•5h ago•97 comments

A New Geometry for Einstein's Theory of Relativity

https://www.quantamagazine.org/a-new-geometry-for-einsteins-theory-of-relativity-20250716/
74•jandrewrogers•9h ago•2 comments

Show HN: Simulating autonomous drone formations

https://github.com/sushrut141/ketu
13•wanderinglight•3d ago•2 comments

How I keep up with AI progress

https://blog.nilenso.com/blog/2025/06/23/how-i-keep-up-with-ai-progress/
170•itzlambda•5h ago•85 comments

Making a StringBuffer in C, and questioning my sanity

https://briandouglas.ie/string-buffer-c/
27•coneonthefloor•3d ago•17 comments

Benben: An audio player for the terminal, written in Common Lisp

https://chiselapp.com/user/MistressRemilia/repository/benben/home
46•trocado•4d ago•4 comments

I'm Rebelling Against the Algorithm

https://varunraghu.com/im-rebelling-against-the-algorithm/
6•Varun08•1h ago•0 comments

Hundred Rabbits – Low-tech living while sailing the world

https://100r.co/site/home.html
216•0xCaponte•4d ago•60 comments

How to Get Foreign Keys Horribly Wrong

https://hakibenita.com/django-foreign-keys
50•Bogdanp•3d ago•24 comments
Open in hackernews

Linear Programming for Fun and Profit

https://modal.com/blog/resource-solver
62•hmac1282•2mo ago

Comments

ayhanfuat•2mo ago
> X = [x1, ..., Xn]: instances of each type to launch

Is this a continuous variable? Seems discrete to me. I am surprised it is solved by simplex.

Frummy•2mo ago
It's the answer, a vector of integers
ayhanfuat•2mo ago
Simplex cannot give a vector of integers though, unless the constraint matrix is unimodular. Maybe the integrality constraint was relaxed.
cweld510•2mo ago
You're right -- we do relax the integrality constraint, gaining performance at the expense of some precision, and we're generally able to paper over the difference at scheduling time. We've investigated integer linear programming for some use cases, but for solves to run quickly, we have to constrain the inputs significantly.
ayhanfuat•2mo ago
Thanks for the clarification. I guess it wouldn’t matter much if the numbers are large. Initially I thought they were mostly ones and zeros.
stncls•2mo ago
If this is business critical for you, you may want to switch to a faster solver. Glop is very nice, but it would be reasonable to expect a commercial solver (Gurobi, XPress, COpt) to be 60x faster [1]. By the same measure, the best open source solvers (CLP, HiGHS) are 2-3x faster than Glop.

Actually, the commercial solvers are so fast that I would not be surprised if they solved the IP problem as fast as Glop solves the LP. (Yes, the theory says it is impossible, but in practice it happens.) The cost of a commercial solver is 10k to 50k per license.

[1] ... this 60x number has very high variance depending on the type of problem, but it is not taken out of nowhere, it comes from the Mittelmann LP benchmarks https://plato.asu.edu/ftp/lpopt.html There are also benchmarks for other types of problems, including IP, see the whole list here: https://plato.asu.edu/bench.html

petters•2mo ago
If you are able to paper over the fractional numbers and get a usable solution, an integer solver should also be able to find a feasible solution easily. Perhaps not optimal, but better than just solving the LP and rounding
hustwindmaple1•2mo ago
You are basically doing a heurstic. Your solutions are not guaranteed to be optimal. Integer programming is the way to do.
cweld510•2mo ago
Great to see this post here -- really enjoyed writing it! I think it's really cool how an algorithm from an operational research context can play a critical role in a high-availability large-scale cloud service.
sumtechguy•2mo ago
LP is a shockingly good way to optimize a system. If you can put inputs/outputs into the correct form. Had an econ prof that loved these things for doing supply/demand maxima and minimum finding. He didnt outright say it but I think it was his current line of study when I was taking classes from him the 90s. I thought that, as he managed to bring it up in every class he taught.
Onavo•2mo ago
Well, kantorovich did win the Nobel for inventing that.
underanalyzer•2mo ago
Neat article. I do wish it mentioned that there are polynomial time algorithms to solve linear programming problems. According to the Google ortools docs it has the option to use those as well (but not with the GLOP solver). Might be good for when simplex is struggling (https://developers.google.com/optimization/lp/lp_advanced)
stncls•2mo ago
You're right, but it's very subtle and complicated.

In theory, the simplex method is not known to be polynomial-time, and it is likely that indeed it is not. Some variants of the simplex method have been proven to take exponential time in some worst cases (Klee-Minty cubes). What solvers implement could be said to be one such variant ("steepest-edge pricing"), but because solvers have tons of heuristics and engineering, and also because they work in floating-point arithmetic... it's difficult to tell for sure.

In practice, the main alternative is interior-point (aka. barrier) methods which, contrary to the simplex method, are polynomial-time in theory. They are usually (but not always) faster, and their advantage tends to increase for larger instances. The problem is that they are converging numerical algorithms, and with floating-point arithmetic they never quite 100% converge. By contrast, the simplex method is a combinatorial algorithm, and the numerical errors it faces should not accumulate. As a result, good solvers perform "crossover" after interior-point methods, to get a numerically clean optimal solution. Crossover is a combinatorial algorithm, like the simplex method. Unlike the simplex method though, crossover is polynomial-time in theory (strongly so, even). However, here, theory and practice diverge a bit, and crossover implementations are essentially simplified simplex methods. As a result, in my opinion, calling iterior-point + crossover polynomial-time would be a stretch.

Still, for large problems, we can expect iterior-point + crossover to be faster than the simplex method, by a factor 2x to 10x.

There is also first-order methods, which are getting much attention lately. However, in my experience, you should only use that if you are willing to tolerate huge constraint violations in the solution, and wildly suboptimal solutions. Their main use case is when other solvers need too much RAM to solve your instance.

underanalyzer•2mo ago
Very interesting! Thanks for the reply. I wonder if they tried these other solvers and decided they were either too slow b/c their problems were too small or the answers were too inaccurate
Onavo•2mo ago
The most interesting question is how you scrape the prices. The cloudprovider really need to provide an API.