Does Ubuntu 20.04 LTS have an upper memory limit for Java processes?

bzero

4/6/23, 9:10 PM

I've got this problem: There is a server running "Ubuntu 20.04.1 LTS" and a JDK 8 application. The machine has 256 GB of memory.

Currently the JVM is started with the arguments -Xms25g -Xmx25g, however I want the JVM to use 32g or even more and I want to set the size immediately so that it's reserved and not calculated at runtime.

If I start the JVM with -Xms32g -Xmx32g it crashes after startup, with 25gb it doesn't.

The JVM wrote an error dump, starting with

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007fe590e47acb, pid=778060, tid=0x00007fdd5d090700
#
# JRE version: OpenJDK Runtime Environment (8.0_282-b08) (build 1.8.0_282-8u282-b08-0ubuntu1~20.04-b08)
# Java VM: OpenJDK 64-Bit Server VM (25.282-b08 mixed mode linux-amd64 )
# Problematic frame:
# V  [libjvm.so+0x87dacb]
...

Otherwise there is no exception or error written in any logs I checked.

So I wonder whether there is a limit somewhere I'm not aware of?

0 + 0

java

jdk

openjdk

guiverc

4/6/23, 9:13 PM

Are you asking about Ubuntu Core 20? or Ubuntu 20.04 LTS, as 20 & 20.04 are used by different Ubuntu products & you mention both.

matigo

4/6/23, 10:28 PM

The `-xms` option sets the initial size, but is not a minimum reserved amount as GC will come along and reduce the allocated memory if any can be freed. `-xmx` sets a maximum *heap* size, but this is not a memory limit for the JVM, which can use a great deal more than the amount set aside just for the heap. As there is no information regarding what it is you’re trying to run, it will be difficult to offer alternative numbers. That said, these two values do not need to match. Consider trying something like `-xms16g -xmx32g` and see if the exception persists

bzero

4/21/23, 4:09 PM

Hi @matigo, well it does not matter what my application does. Maybe it does nothing but nonetheless I want to give it 64g, so why is it not possible on Ubuntu 20.04 LTS?

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Does Ubuntu 20.04 LTS have an upper memory limit for Java processes?

TH: Ubuntu 20.04 LTS มีหน่วยความจำสูงสุดสำหรับกระบวนการ Java หรือไม่

RO: Ubuntu 20.04 LTS are o limită superioară de memorie pentru procesele Java?

RU: Есть ли в Ubuntu 20.04 LTS верхний предел памяти для процессов Java?

VI: Ubuntu 20.04 LTS có giới hạn bộ nhớ trên cho các quy trình Java không?

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