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Java has huge ecosystem in enterprise dev, but very unlikely it has ecosystem edge in high performance/real time compute.

Java has significant overhead, that most/every object is allocated on heap, synchronized and has extra overhead of memory and performance to be GC controlled. Its very hard/not possible to tune this part.

You program differently for this niche in any language. The hot path (number crunching) thread doesn't share objects with gateway (IO) threads. Passing data between them is off heap, you avoid object creation after warm up. There is no synchronization, even volatile is something you avoid.

> Passing data between them is off heap

how exactly you are passing data? You can pass some primitives without allocating them on heap. You can use some tiny subset of Java+standard library to write high performance code, but why would you do this instead of using Rust or C++?


In some places I'm using https://github.com/aeron-io/agrona

Strangely this is one of the areas where I want to use project panama so I might re-implement some of the ring buffers constructs.

You allocate off heap memory and dump data into it. With modern Java classes like Arena, MemoryLayout, and VarHandle it's honestly a lot like C structs.

I answered "why" in another post in this thread.


> You allocate off heap memory and dump data into it. With modern Java classes like Arena, MemoryLayout, and VarHandle it's honestly a lot like C structs.

my opinion is that no, it is not, declaring and using C struct is 20x times more transparent, cost efficient and predictable. And that's we talking about C raw stucts, which has lots of additional ergonomics/safety/expression improvements in both c++ and rust on top of it.


it doesn't mean Java is optimal or close to optimal choice. Amount of extra effort they do to achieve goals could be significant.

Optimal in what sense? In the java shops I've worked at it's usually viewed as a pretty optimal situation to have everything in one language. This makes code reuse, packaging, deployment, etc much simpler.

In terms of speed, memory usage, runtime characteristics... sure there are better options. But if java is good enough, or can be made good enough by writing the code correctly, why add another toolchain?


> But if java is good enough, or can be made good enough by writing the code correctly,

"writing code correctly" here means stripping 95% of lang capabilities, and writing in some other language which looks like C without structs (because they will be heap allocated with cross thread synchronization and GC overhead) and standard lib.

Its good enough for some tiny algo, but not good enough for anything serious.


It's good enough for the folks who choose to do it that way. Many of them do things that are quite "serious"... Databases, kafka, the lmax disruptor, and reams of performance critical proprietary code have been and continue to be written in java. It's not low effort, you have to be careful, get intimate with the garbage collector, and spend a lot of time profiling. It's a totally reasonable choice to make if your team has that expertise, you're already a java shop, etc. I no longer make the choice to use java for new code. I prefer rust. But neither choice is correct or incorrect.

> Databases, kafka, the lmax disruptor, and reams of performance critical proprietary code have been and continue to be written in java.

those have low bar of performance, also they mostly became popular because of investments from Java hype, and rust didn't exist or had weak ecosystem at that time.


> there is a large class of programs that can be expressed very simply using async rust but would be very complicated to express in sync rust (assuming equivalent performance).

I challenge that this class is large, at least in the area of my expertise: backend and data processing.


ships are carriers of cruise missiles they can launch from 2k miles distance out of range of swarm of drones.

Why do you spell Lviv capitalized but Ukraine not? You are too xenophobic toward Ukrainians?

Be serious. I don't care about any of europe; the rest of the west is doing just fine caring about it incessantly at the top of their voices regardless of who asked. My heart belongs in east africa.

I'll try to be more sensitive with what I capitalize—but I don't really give a damn about either ukraine or russia—both seem like far-right corrupt states that don't take care of their citizens well—though I do feel very sad for the humans caught between them.


> ukraine or russia—both seem like far-right corrupt states that don't take care of their citizens

what makes you think Ukraine is far-right corrupt state, what would you do differently if you would be Zelenskiy (jew btw).


Iran is real threat to oil circulation in that region, they applied this tactics many times before. Now imagine if we come to current situation 5 years later when Iran has missiles with nuclear warheads?

> they applied this tactics many times before

Feel free to list the details about when, how and why it happened before ;) interestingly none of these scenario would even have happened if they had nukes to begin with, how weird


Here is example: https://news.usni.org/2023/04/27/centcom-iranian-naval-force...

> interestingly none of these scenario would even have happened if they had nukes to begin with, how weird

this is very weird speculation, Iran would be way more aggressive in its action in the region if they would have nukes.


The only weird thing in this story is that we keep preemptively bombing the same people for at best vague reasons (they were about to attack us trust me bro) and at worst complete made up lies (they have mass destruction weapons, look at my jar of anthrax).

> they were about to attack us trust me bro

depends how you define "attack us". Iran is part of Iran-Russia-China axis, which goals are very explicit in expanding influence and territories (Ukraine, Taiwan, Syria, Iraq, Gulf states). If they succeed, Western world will be cut from semiconductors and oil and become much weaker.


Might, may, could, potentially, maybe... Virtually nothing happened in decades and now that the US/Israel decided time was up the situation is more fucked than it has ever been, potentially pushing the Iranian government into more radicalism, good job! That will teach them. "we had to attack because they could theoretically cut us from oil in a distant future", how is it going so far?

How did it go in Iraq? Afghanistan? What's up with kidnapping Maduro? Is this what the "western world" is about? Securing resources by bombing people preemptively because they might do something you don't like one day?

You can't look at the recent history of the region and point the finger at literally anyone else other than the US with a straight face lmao, you're the blood thirsty nation who's military industrial complex got out of hand, just watch the latest videos posted by the official white house accounts, only psychopaths would come up with these


> Virtually nothing happened in decades

it was decades of very intense proxy wars: Yemen, Syria, Iraq, Gaza, Lebanon. Iran didn't hesitate to attack oil assets: https://en.wikipedia.org/wiki/Abqaiq%E2%80%93Khurais_attack

> Is this what the "western world" is about? Securing resources by bombing people preemptively because they might do something you don't like one day?

sure, that's what humans do through centuries. If you don't do it, you get extinct because other forces become stronger and bomb you.


> it was decades of very intense proxy wars: Yemen, Syria, Iraq, Gaza, Lebanon. Iran didn't hesitate to attack oil assets

Compared to the US and Israel who only mind their own business and never do any shady things of course. Russia says the same thing about the US in Ukraine, but there it's a dirty propaganda lie, when it comes to Iran it's just the Real Truth ™


Plenty of other nations (including Iran for decades) are not getting this stick. Carrots were even offered. The USA has remained remarkably calm remarkably long. Imagine this had been executed before Hamas parachuted a Jewish music festival? Gaza wouldn't have been sandwiched between Israel on one side and Iran's Hamas on the other. Imagine Iran had fallen (it hasnt yet) before that event. Israel wouldn't possibly have been able to "justify" doing a genocide in Gaza even to its own population!

Inaction is a weapon of mass destruction.


you are putting words in the mouth of your discourse partner: approaching nuclear weapons capabilities is the reason for attack, waiting until its too late is obviously not considered an option.

Like when Iraq was just about to drop anthrax all over the US? We should study the psychology of normies falling over and over for the same propaganda techniques even when it goes again their own interests

maybe its unlike Iraq situation this time.

its partial satire. I kinda believe Claude/Codex spill lots of OSS code without license attribution for many millions of devs already.

It wouldn't be funny if it wasn't close to the truth.

> Japan debt/GDP is more than twice the US's.

Japan borrows on 0.75% interest rate compared to current US's 3.5%.



Its way more painful for rest of the world except Russia, and not US. They will make little pain on US, and make world and neighbors extremely angry on them.

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