HN user
Happens all the time. Here's another good one: https://www.nbim.no/ (the Norwegian Sovereign Wealth Fund)
Is a <1s live ticking number implausibly high frequency? Of course, it's just spooling out numbers on a timer.
LDPE (thicker, 'bag for life' etc) is about 4 times as bad, paper bags 3 times, vs HDPE (thin) bags assuming no reuse. The below UK gov study investigates impact of each (and other alternatives like cloth bags) and also considers reuse as bin liners, which significantly changes the numbers.
https://assets.publishing.service.gov.uk/government/uploads/...
With Java vs C++, the experience seems similar. In C++, memory allocation is slow, so you worry about memory allocation up front. In Java, GC is a pain so you worry about memory allocation up front. As Daniel points out, there are a few extra tricks available to native developers (eg vector instructions), so there's a small factor speed-up in best-practice C++ vs best-practice Java, but this is closing (eg the JIT increasingly uses vector instructions). Overwhelmingly the difference between a slow system and a fast system is appropriate choices of algorithms and architecture, not the language.
The compression format is really smart, there's a neat trick to make the logarithm calculation fast, and there's a concurrent thread handoff mechanism so you can swap out a histogram without disturbing the thread you're measuring (though last two probably only in the java version). Those three make it super useful for very low impact performance measurements.
Google claims 3.5 billion queries per day, so approaching 1% of that.
Congratulations!
High frequency trading?
That's pretty interesting. Is there a concrete example of a quorum definition where the probability of an outlier is improved vs majority quorum? I'm struggling to come up with one. I've always assumed majority is optimal, since you can tolerate outliers in (n-1) / 2 voters without seeing an outlier for the commit overall. Eg: for 3 node Raft - you'd need both followers to have an outlier before a client notices a slow commit.
EM Forster took your thought experiment to it's logical conclusion for you: https://en.wikipedia.org/wiki/The_Machine_Stops
On hotspot: There are two bits in the header of every object. This is enough for an object that's never been used as a contended lock, CAS operations on the header can be used to handle the locking and that's that. As soon as you actually block on it, a 'real' lock is created (you can't get around the need for a list of threads to wake up as the lock is released) and the header grows to accomodate it. The process is called 'monitor inflation'. At a later date this might be cleaned up by a 'monitor deflation'.
Quick question: What's the draw of using Netty vs pure java.nio? The latter (Selectors, Socket/DatagramChannels, ByteBuffers etc) seems reasonably straightforward to use, so I've never really looked at a framework - am I missing out?
The distinction arises when the full text of a clause is not possible to claim by law, but some weakened or lesser version is OK: If you missed the 'maximum extent permissible' part, your clause would be completely invalidated. Its a hedge.
Yes, given the solarflare I was expecting the article to end up with a receiver coded against ef_vi, which exposes the NIC memory directly (but you have to do the IP/UDP yourself)
So arm compilers must prefer to, for example, XOR with 0x10000000 rather than AND with 0xEFFFFFFF?
My hours are pretty heavy: 55ish hours is an easy week, bad weeks can get a lot worse. It really varies team to team and I think a lot of people in my firm do 9-6 consistently, so if it's a dealbreaker then just ask about it explicitly during the interview. I'd definitely give it a shot (or a few shots, since the recuitment process is indeed a lottery)
80k base, 130k last bonus. I'm 2 years into doing mostly Java, Python and C++ in a hedge fund. I left a small non-finance software firm where after a few years I was on 25k.
It's also the shortest C program that you can link at all.
Sensationalist headline. "Top industries" - when ranked by environmental impact. Kinda renders the article a tautology?
Do you have any visibility on what it was that triggered your change? I don't mean to pry, achieving a genuine change of outlook is rare, fascinating and to be celebrated. A lot of time the internal struggle is worsened because there doesn't seem to be any way to break out of the thinking patterns.
You know this includes all recent Intels right? AMD64 here means "the 64 bit extension to x86 that's not the Itanium one"
Normally a curmudgeon, I love everything about this story. The original comic is brilliant, and the various HN takes on it are getting better and better. Thanks everyone!
Agreed. I "proved my point" but I didn't do it "by supplying 0.1 in a binary floating point format", because that wasn't what my point was.
Sure adaml_623,
0x3dcccccd in IEEE 754-2008 (binary32) corresponds to the interval (0.09999999776482582, 0.10000000521540642) - which contains 0.1.
Disclaimers: I worked this out with double precision, and if you care about if the endpoints are inclusive/exclusive, the wikipedia article will help.
Sure it does - in that any floating point scheme is a well defined partition of the real line in the range [-FLT_MAX, +FLT_MAX] into 2^n intervals (less two Infs, a load of NaNs and a spare zero), one of which absolutely contains 0.1
Uh, because with a drawn symbol you wouldn't need their thirty dollar notebooks?
My point is that should there exist some higher level structure in the brain that is more amenable to simulation than the equivalent quantity of low-level synapses and neurons, then all bets are off about exactly what sort of computer is required to simulate it. The brain has to be replicable by biological processes - who knows what tricks it has to pull to achieve its function? Maybe it's possible to come up with an 'optimizing compiler' that tosses the junk.
Presumably you're referring to the neuron-level simulations that crop up in the news every time some university gets a new supercomputer? Maybe there are some shortcuts.
Just like 10 years ago the only conceivable way of rendering diffuse light was with raytracing or radiosity simulations. Now we have modern techniques like ambient occlusion that makes it reasonably cheap to do in a rasterizer in realtime.
Apple do the 2x stuff on iOS so that the large set of handcrafted, bitmapped 1x apps can map precisely to pixels when you upscale them. OSX doesn't have the same issue, since there's no existing default screen size that is designed for.
Really? requiring a shell alias or a one line shell script to shorten your invocation makes the entire language 'totally unusable'?
In other news a Knight Capital programmer's fat fingers cost exactly the amount of money required to build a Space Shuttle.