I am using the G1 garbage collector with JDK1.7.0, but the VM does not recognize the option G1YoungGenSize. Specifically, when I run:
java -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1YoungGenSize=512m ...
I get the following error:
Unrecognized VM option 'G1YoungGenSize=512m'
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.
I have also tried it with a "+" sign before G1YoungGenSize, as some of the G1 documentation lists it that way:
java -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:+G1YoungGenSize=512m ...
But I get the same error.
I have tried older JDKs, including 1.6 update 18 through 21. It seems that G1YoungGenSize is recognized through update 20, and breaks beginning with 21 and through the latest 1.7 build (snapshot dated August 19, 2010).
Does anyone know what could be causing this error?
This looks to have changed about 6 months ago:
6928065: G1: use existing command line parameters to set the young generation size
http://hg.openjdk.java.net/jdk7/jdk7/hotspot/rev/a1c410de27e4
Changes made for 1.6 here:
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6928065
To be consistent with the other GCs, G1 should observe UseAdaptiveSizePolicy to decide whether to auto-tune the young generation size. NewSize / MaxNewSize (and also -Xmn) should dictate the initial max size.
Related
About the following message:
Could not reserve enough space for 3145728KB object heap
I need some tips to understand what's going on
Points & Observations:
Running over Windows 10 x64 (16G Memory)
It only happens using this distribution: https://jdk.java.net/java-se-ri/8-MR3
It works fine using the build from AdoptOpenJDK: https://adoptopenjdk.net/?variant=openjdk8&jvmVariant=hotspot
At pom.xml, I've tried to add the following line: <extraJvmArgs>-Xms1G -Xmx4G -Xss1M -XX:-UseGCOverheadLimit -XX:MaxHeapSize=4G</extraJvmArgs>. But it "complains" The specified size exceeds the maximum representable size. (The original Xmx and MaxHeapSize was 3G)
Main Objective: To compile a project that was done previously using Oracle JDK8 with the Open JDK8
Any "lights"?
------ Edit
arg -d64 returns Error: This Java instance does not support a 64-bit JVM.
Maybe it's 32 bits the compilation from Java website?
I have been using the following flags in my application using Java 8:-
1) PrintFLSStatistics=1
2) +PrintPromotionFailure
3) -XX:+PrintGCDateStamps
4) -XX:+PrintGCDetails
I have been moving the application to use Java 11 instead of Java 8. It seems these flags are either deprecated or not supported in Java 11. Please tell the alternatives of these flags in Java 11.
Thanks for your time,
In Java 11, you have to use -Xlog instead. For example: java -Xlog:gc\*::time -jar my.jar will log something like
[2020-02-19T18:32:50.107-0300] Heap region size: 1M
[2020-02-19T18:32:50.119-0300] Using G1
[2020-02-19T18:32:50.119-0300] Heap address: 0x000000070a200000, size: 3934 MB, Compressed Oops mode: Zero based, Oop shift amount: 3
-Xlog is the general logging configuration option for logging in the HotSpot JVM. It's a tag-based system where gc is one of the tags. To
get more information about what a GC is doing, you can configure
logging to print any message that has the gc tag and any other tag.
The command line option for this is -Xlog:gc*.
See:
https://docs.oracle.com/javase/9/tools/java.htm#GUID-BE93ABDC-999C-4CB5-A88B-1994AAAC74D5
https://docs.oracle.com/en/java/javase/11/gctuning/garbage-collector-implementation.html#GUID-A24775AB-16A3-4B86-9963-76E5AC398A3E
I am new to ElasticSearch, but already in trouble.
My configuration:
Windows 7 Enterprise 64 bits
8 Gb RAM
I am unsuccessful at simply starting the instance, using elasticsearch.bat :
Error occurred during initialization of VM
Could not reserve enough space for object heap
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.
Adter exploring SO forums as well as ElasticSearch support pages, here is what I tried:
setting min and/or max heap memory (using SET ES_MAX_MEM and SET ES_MIN_MEM on the command line before calling elasticsearch.bat) to various values, from 256m/512m to 256m/3g ==> no change in error message
setting heap size (using SET ES_HEAP_SIZE on the command line before calling elasticsearch.bat) to various values, from 256m to 3g ==> no change in error message
uninstalled my Java 7 environment and fresh installed Java 8 64 bits (checked through java -version on the command line) ==> no change in error message
Surprisingly enough, I can't seem to find any logging information (no 'logs' directory present in %ES_HOME% where the elasticsearch.org documentation states it should be...)
Would anyone point me to the right direction to get the thing up and running?
Thanks a lot
Finally got it sorted out by forcing JAVA_HOME to point to my fresh Java 8 install (seems 'java' command resorted to old java install although the Java 8 installer claimed it had cleaned previous installs).
Thanks a lot
How can I trigger a heap dump for a Java 7 VM running on Linux without having a JDK installed?
In earlier versions of Java it was possible to set the -XX:+HeapDumpOnCtrlBreak JVM option and then trigger a heap dump by using kill -QUIT <pid>. I have been unable to get this to work with Java 7. Is there an equivalent to this without needing the JDK installed to get JVisualVM or jmap.
VM option -XX:+HeapDumpOnCtrlBreak is no longer listed at http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html. So, I conclude that it's no longer supported.
From http://www.oracle.com/technetwork/java/javase/tech/vmoptions-jsp-140102.html:
Options that are specified with -XX are not stable and are subject to
change without notice.
You can generate a core dump with gcore, move it to another machine, and attach jmap to generate hprof file as described in Core dump taken with gcore, jmap conversion to hprof file format fails with Error message
See also accepted answer.
I've connected to a linux-based server using ssh. Recently, I've installed JDK using following command:
sudo yum install java-1.6.0-openjdk-devel
And jdk installed successfully, but whenever I run command java or javac I get following error:
Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.
Even, running command java -version, will bring that error. When I try to give java more space using java -Xmx512m -Xms256m -version, I'll get following error:
*** glibc detected *** java: double free or corruption (!prev): 0x00007fc84400e270 ***
*** glibc detected *** java: double free or corruption (fasttop): 0x00007fc8440089f0 ***
#
Aborted (core dumped)
How can I resolve this?
Thanks in advance
I have never seen this sort of exception, so it is my best guess: did you try to limit stack size by using -Xss JVM parameter (i.e. -Xms8m -Xmx16m -Xss4m)? Also quick googling suggest that export MALLOC_CHECK_=0 could possibly let you get over, but I am not sure if JVM will function well.
A virtual Linux server?
What do you get when run:
java -Xmx1m -version
and
ulimit -a
Looks like a memory allocating problem. You can try to increase swap space if possible.
To me it looks like there is not enough memory to run the virtual machine (maybe physical memory, virtual memory or ulimit) - you should try decreasing the memory allocated to the VM (I think the default in 64Mb) and not increasing it.
Lower your -Xms (not xmx).Use -Xms40m for example.If it starts as it is stated in other answers, you may be too low on memory to reclaim 256m for the vm at start.
Looks like you are using JDK 32-bit version. If so, you cannnot assign a Heap size more than 1.2GB or something.
Either use a 64 bit JDK or try with 1.2G as the max heap size.