CODEWITHSUNDEEP
javaout-of-memory32-bitvisualvmadoptopenjdk
tarekahf
tarekahf

Reputation: 1002

OpenJDK errors java.lang.OutOfMemoryError: Java heap space and Could not reserve enough space for 1048576KB object heap

The team switched from Oracle JRE 1.8 to OpenJDK. Started the test with this version:

java-1.8.0-openjdk-1.8-Ø.372

Things were OK until load testing started and moved to a higher staging environment. The team started getting the following errors:

Cannot start the application with -Xmx1024m:

Error occurred during initialization of VM
Could not reserve enough space for 1048576KB object heap

Then, change the JVM memory parameter to -Xmx512m (or kill some unwanted background services/tasks on Windows Server), the application will start successfully and then start throwing the following errors halfway through load testing:

java.lang.OutOfMemoryError: Java heap space

There is the following restriction: must use JRE 32-bit version 1.8.0_341 or lower since the JDK used was based on 1.7. The 32-bit is due to using other components that don't work with 64-bit.

I have done extensive research, and came across various articles including this one:

Difference between JVM and HotSpot?

Note that the application has been working for years, without any error, with Oracle's JRE 1.8 update 341.

I have the following troubleshooting plan:

  1. Switch between OpenJ9 and HotSpot OpenJDK

OpenJ9: https://developer.ibm.com/languages/java/semeru-runtimes/downloads/
HotSpot: https://adoptium.net/temurin/releases/?version=8

  1. Try a lower or higher version of OpenJDK since there is no one-to-one mapping between the Oracle JRE version and that of OpenJDK.

  2. Try other GC Algorithms based on this article:

https://developers.redhat.com/articles/2021/11/02/how-choose-best-java-garbage-collector

  1. Submit a ticket to Redhat support.

I need your help to find other troubleshooting options, and in particular, how to use Java tools to start profiling and memory debugging to see what is going wrong.

Update 1:

In the following, I will provide info about the OpenJDK and other details.

openjdk version "1.8.0_372"
OpenJDK Runtime Environment (build 1.8.0_372-b07)
OpenJDK Server VM (build 25.372-b07, mixed mode)

Property settings:
    awt.toolkit = sun.awt.windows.WToolkit
    file.encoding = Cp1252
    file.encoding.pkg = sun.io
    file.separator = \
    java.awt.graphicsenv = sun.awt.Win32GraphicsEnvironment
    java.awt.printerjob = sun.awt.windows.WPrinterJob
    java.class.path = .
    java.class.version = 52.0
    java.endorsed.dirs = C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre\lib\endorsed
    java.ext.dirs = C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre\lib\ext
        C:\Windows\Sun\Java\lib\ext
    java.home = C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre
    java.runtime.name = OpenJDK Runtime Environment
    java.runtime.version = 1.8.0_372-b07
    java.specification.maintenance.version = 4
    java.specification.name = Java Platform API Specification
    java.specification.vendor = Oracle Corporation
    java.specification.version = 1.8
    java.vendor = Red Hat, Inc.
    java.vendor.url = https://developers.redhat.com/
    java.vendor.url.bug = https://bugzilla.redhat.com/enter_bug.cgi
    java.version = 1.8.0_372
    java.vm.info = mixed mode
    java.vm.name = OpenJDK Server VM
    java.vm.specification.name = Java Virtual Machine Specification
    java.vm.specification.vendor = Oracle Corporation
    java.vm.specification.version = 1.8
    java.vm.vendor = Red Hat, Inc.
    java.vm.version = 25.372-b07
    line.separator = \r \n
    os.arch = x86
    os.name = Windows Server 2019
    os.version = 10.0
    path.separator = ;
    sun.arch.data.model = 32
    sun.boot.class.path = C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre\lib\resources.jar
        C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre\lib\rt.jar
        C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre\lib\sunrsasign.jar
        C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre\lib\jsse.jar
        C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre\lib\jce.jar
        C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre\lib\charsets.jar
        C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre\lib\jfr.jar
        C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre\classes
    sun.boot.library.path = C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\jre\bin
    sun.cpu.endian = little
    sun.cpu.isalist = pentium_pro+mmx pentium_pro pentium+mmx pentium i486 i386 i86
    sun.desktop = windows
    sun.io.unicode.encoding = UnicodeLittle
    sun.java.launcher = SUN_STANDARD
    sun.jnu.encoding = Cp1252
    sun.management.compiler = HotSpot Tiered Compilers
    sun.os.patch.level =
    sun.stderr.encoding = cp437
    sun.stdout.encoding = cp437
    user.country = US
    user.dir = C:\Program Files (x86)\RedHat\java-1.8.0-openjdk-1.8.0.372-1\bin
    user.language = en
    user.script =
    user.timezone =
    user.variant =

Does this mean that I am using HotSpot OpenJDK?

Processor: Intel(R) Xeon(R) Platinum CPU @ 2.20GHz 2.19 GHz (16 processors)
Installed memory (RAM): 64.0 GB
System type: 64-bit Operating System, x64-based processor
Pen and Touch: Pen and Touch Support with 10 Touch Points

Upvotes: 0

Views: 986

Answers (1)

Jagan
Jagan

Reputation: 35

There is space limitation for 32-bit process. Each process can use up to 2GB. (Refer another SO Answer)

You can use OpenJ9 JVM from IBM (still IBM support 32bit version for Java 8) which can significantly reduce overall memory footprint and you can start your application. JDK Link

Upvotes: 1

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