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Comment by tracker1 | Hacker News Reader

I know that you are probably going to be modded into oblivion, but can Java address this much memory in a single application? I'm genuinely curious, as I would assume, depending on the OS that you'd have to run several (many) processes in order to even address that much ram effectively.

Still really cool to see something like this, I didn't even know you could get close to 2TB of ram in a single server at any kind of scale.

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Bigger iron has been at 64-512 TB for a while:

http://www.cray.com/blog/the-power-of-512-terabytes-of-share...

http://www.enterprisetech.com/2014/10/06/ibm-takes-big-workl...

Or significantly higher if you don't restrict yourself to single-system-image, shared memory machines - there are at least 2 1300-1500 TB systems on the Top 500 list.

Not using the out of the box solutions. But while I haven't done this personally my understanding is Azul Zing will allow you to efficiently use multi TB heaps in Java.

Java can address 32GB heaps with compressedoops flag enabled. After that flag is off, you can address as much as 64 bits will allow. http://stackoverflow.com/questions/2093679/max-memory-for-64...

Do a little research before implying that there's no way that Java can address gigantic heaps.

I wasn't implying or assuming anything, I was genuinely asking... I'm more familiar with windows, than other OSes, but iirc, windows apps can only get 4GB per process. (Maybe that was just 32bit windows apps).

I was incorrect... Then again, I've never needed to address more than a couple gb of ram.

[1] http://stackoverflow.com/a/11892191/43906

Just 32bit apps. 64bit apps can go much higher.

You can but garbage collection will kill your performance for very large heaps. You either end up needing to use off heap memory to take it out of scope for garbage collection or using many small JVMs with more reasonable sized heaps.

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