I have got a problem. My program is really big and java is throwing OutOfMemoryException.
In .bat file, I have got the following:
java -server -Dfile.encoding=UTF-8 -Xmx1500m -Xbootclasspath/p:../libs/l2ft.jar -cp config/xml;../libs/*; l2ft.gameserver.GameServer
Java is using 6 GB of my RAM, next 6 GB is not used.
I typed System.getProperty("sun.arch.data.model"); and it says that I am using 64-bit JVM.
You have set the maximum heap size to 1500m and while the JVM can use a little more than that ~200 MB, that's all you limited the process to.
Try instead to limit your progress to around 5 GB. (You want to leave some memory for overhead and the OS)
-mx5g
Make the options before Xbootclasspath this:
java -XX:MaxPermSize=512m -server -Dfile.encoding=UTF-8 -Xmx8g -XX:+UseCompressedOops
This will make it use more memory and will also make sure it uses as little memory as possible to address the objects in a 64bits machine.
The -XX:MaxPermSize=512m makes the perm gem space larger (which you will probably need as you're using a lot of heap memory) and the -XX:+UseCompressedOops will make it use 32bits addressing for objects, instead of 64bits, as a 8gb heap can be correctly addressed with 32bits, so it makes you use less memory for allocating objects.
Related
This might be an odd question but since its java related I'll ask it here, I'm trying to play minecraft with a mod that is requering at least 2GB RAM but everytime i try to put 2048MB it shows:
Error occurred during initialization of VM
Could not reserve enough space for 2097152KB object heap
Java HotSpot(TM) Client VM warning: Using incremental CMS is deprecated and will likely be removed in a future release
I'm using this codes I don't know if it will help anything -Xms2048m -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128m.
The only way to make it work is to set the xms to 1024MB and that make sjava run out of memory, how can i set java to us emore memory, I'm using Win10 64-Bit, Java 8 121 64bit, I have 16GB Ram.
Help?
You just need to edit the Xms and Xmn to whatever size you want them to be. You won't get much benefit from allocating big amounts of RAM, it'll just release pressure from the CPU since it'll have to do less deallocating. Tell me if it works, and if it doesn't try to be more specific on what you're doing.
I am trying to run some .jar file but I am getting below error. The system has 20 gb of ram and my Xms and Xmx values are -Xms2048m -Xmx4096m
Are these values are too big or there is another thing causing this error?
java.lang.OutOfMemoryError: Java heap space
EDIT:
java -jar -Xms2048m -Xmx4096m /Filereadertest.jar
I am using java 1.7.51
Java HotSpot(TM) 64-Bit Server VM
Are these values are too big or there is another thing causing this error?
The default for the server JVM is 1/4 of main memory or 5 GB, so you are actually decreasing the maximum by setting this.
You could set it to 80% of main memory such as -Xmx16G
Along with JRE version and architecture, heap space per process also depends upon the operating system in use.
For example, Windows 32-bit allows maximum 2 GB memory per process, which also includes size for stacks, libraries and other stuff. So in practice, we generally get 1.25 GB memory.
Have a look at:
Oracle's Guidelines for Heap Space Sizing
I have an application that on launch requests a specific amount of RAM using the following command.
java -Xms512m -Xmx985m -jar someJarfile.jar
This command fails to run on my computer with 8.0GB of RAM because it can not create an object heap of the specified size. If I lower the max range to something below 700MB it works fine.
What is even stranger is that even doing a simple java -Xmx768m -version fails when the -Xmx flag value exceeds 700m. I am trying to run it with Java 1.7Uu67 32-bit(that is what the jar was built with) and even newer versions of Java 1.7 and event Java 1.8. I would understand if the max heap was higher and I was using 32bit, but it is not above the ~1.4GB cap of 32-bit java
Is there a configuration parameter that I am missing somewhere that would be causing this, some sort of software that may be interfering? It does not make sense to me as to why I can not allocate 700MB of RAM on a machine with 8.0GB of RAM. I
I should also note that there are no other processes running that are taking up all of my RAM. It is a fresh install of Windows 7.
While 700 MB is pretty low, it is not surprising.
The 32-bit Windows XP emulator in Windows works the same way as Windows XP with all it's limitations. It means you lose 2 GB or a potential 4 GB to the OS. This means programs already running use up virtual memory space. Also if your program uses shared libraries or off heap storage like direct memory and memory mapped files this will means you lose virtual memory for the heap. Effectively you are limited to 1.4 GB of virtual memory for your applications no matter how much memory you actually have.
The simple way around this it to use the 64-bit JVM which runs in your 64-bit OS and is also limited but instead to 192 TB of virtual memory on Windows.
You should try using a 64 bit Java Runtime. It is probably the case that there is no 985 MB large one-piece memory chunk free within the 32-bit address space of your computer (the 32 bit address space 4GB). When you use a 64 bit Java Runtime, Java can allocate the memory within the 64 bit address space, in which the free memory is much more likely to be available.
It doesn't matter that your JAR file was built using a 32 bit version.
The answer to your question may lie in the fact that Windows tries and fails to find a contiguous block of memory that is large enough: see http://javarevisited.blogspot.nl/2013/04/what-is-maximum-heap-size-for-32-bit-64-JVM-Java-memory.html. (Though this suggests that other processes are hogging memory, which seems to be contradicted by your last remark.)
I have an app that uses the following jvm options:
-Xmx512m -Xms256m -XX:+UseParNewGC -XX:+UseConcMarkSweepGC
-XX:MaxGCPauseMillis=2 -XX:MaxDirectMemorySize=1G
I run it on Windows 7 x64 with 8gb RAM. And when the task manager says that there's 60% of RAM is in use, it becomes impossible to run my program, Java says "Out of memory". Even though in theory I still have almost 3gb of free RAM left. Below are screenshots of profiling my project in NetBeans (until it suddenly crashes on a random spot). What could cause these problems? Is my program really so expensive?
(source: SSmaker.ru)
(source: SSmaker.ru)
You should greedy-allocate your minimum required overhead. That is,
use something like -Xms1g -XMx1g, so when your app actually starts running,
it has already reserved its maximal heap usage.
I am trying to set the Xmx parameter when starting up a program. If I set it to 1408M, the JRE starts up fine. If I set it to 1536M, I get
"Could not create the java virtual machine".
I understand that it's trying to reserve consecutive memory space, but the machine I'm running on has 16GB of RAM and 13GB of that is currently free. The program I'm running is running out of heap space and crashing on me. Is there anything I can do to fix this?
Use a 64bit JVM. The 32bit JVM is limited (depending on the OS) to at most 3 GByte (on linux I have a limitation of about 1.5 GByte).
32-bit JVMs are limited to roughly 1.5 GB of heap space due to addressing constraints and the need for memory for other reasons. On Windows 2 GB is assigned to the process, and 0.5 is used for non-heap memory. If you can use PAE on Windows Server or possibly Linux, you can address up to 3 or 4 GB, respectively.
Otherwise use a 64-bit JVM.