Avoiding Initial Memory Heap Size Error - java

I run a Java code with the following command:
$ java -Xms4G -Xmx4G myjavacode
My cpu's RAM capacity is 6GB.
However it always fail to execute giving me this
error message:
Invalid initial heap size: -Xms5G
The specified size exceeds the maximum representable size.
Could not create the Java virtual machine
Is there any way to set up Java option so that we can
execute the code?

You've exceeded the maximum heap size of your JVM. This is both JVM and OS dependent. In most 32-bit systems the maximum value will be 2Gb, regardless of the physical memory available.

By default Java will run in 32 bit mode. Be sure to give it the -d64 option to put it into 64 bit mode. Once in 64-bit mode, you shouldn't have any trouble allocating a 6GB JVM.

Actually, the maximum memory size on 32-bit systems can vary, being anything up to 4 GB, but 2 GB is a common value. It's often possible to re-link your kernel to increase this to 3 or 3.5 GB. The issue, of course, is that you just don't have the address space to map more memory. Have you tried a 64-bit machine?
Also, remember to set your ulimit higher before you do this.

Related

Setting heap size in Java

I am trying to run a Java tool in Linux Ubuntu system and I keep getting the following error after the program imports 12% of the data:
Fata Error:
Exception in thread 'Thread-l" java.lang.OutOfMemoryError: java heap space
I tried to set the heap size using
java -Xms8G -Xmx16G -jar Haploview.jar
but the error appears again exactly at same point after just using less than 500M Of the allocated Ram.
Using the command 'free -m' I can see that there are lots of free RAM memory left but I don't know why Java do not use it
According to the specification Haploview allocates 512 MB of memory by default. You can increase the memory up to 2000 MB via java -jar Haploview.jar -memory 2000.
For details see https://www.broadinstitute.org/haploview/frequent-questions
But a memory larger than 2 GB is most likely not possible because Haploview seems to be a 32-bit application which is limited to a memory
of 2 GB independent of the underlying OS (32 Bit or 64 Bit).
See https://haploview.software.informer.com/download/
and Memory limit to a 32-bit process running on a 64-bit Linux OS

Java Heap space issue while executing .jar file from the command prompt [duplicate]

I am working on a Windows 2003 server (64-bit) with 8 GB RAM. How can I increase the heap memory maximum? I am using the -Xmx1500m flag to increase the heap size to 1500 Mb. Can I increase the heap memory to 75% of physical memory (6 GB Heap)?
You can increase to 2GB on a 32 bit system. If you're on a 64 bit system you can go higher. No need to worry if you've chosen incorrectly, if you ask for 5g on a 32 bit system java will complain about an invalid value and quit.
As others have posted, use the cmd-line flags - e.g.
java -Xmx6g myprogram
You can get a full list (or a nearly full list, anyway) by typing java -X.
It is possible to increase heap size allocated by the JVM by using these command line options:
-Xms<size> set initial Java heap size
-Xmx<size> set maximum Java heap size
-Xss<size> set java thread stack size
In the following example, minimum heap size is set to 16mb, and the maximum to 64mb:
java -Xms16m -Xmx64m ClassName
On a 32-bit JVM, the largest heap size you can theoretically set is 4gb. To use a larger heap size, you need to use a 64-bit JVM. Try the following:
java -Xmx6144M -d64
The -d64 flag is important as this tells the JVM to run in 64-bit mode.
You can increase the Heap Size by passing JVM parameters -Xms and -Xmx like below:
For Jar Files:
java -jar -Xms4096M -Xmx6144M jarFilePath.jar
For Java Files:
java -Xms4096M -Xmx6144M ClassName
The above parameters increase the InitialHeapSize (-Xms) to 4GB (4096 MB) and MaxHeapSize(-Xmx) to 6GB (6144 MB).
But, the Young Generation Heap Size will remain same and the additional HeapSize will be added to the Old Generation Heap Size. To equalize the size of Young Gen Heap and Old Gen Heap, use -XX:NewRatio=1 -XX:-UseAdaptiveSizePolicy params.
java -jar -Xms4096M -Xmx6144M -XX:NewRatio=1 -XX:-UseAdaptiveSizePolicy pathToJarFile.jar
-XX:NewRatio = Old Gen Heap Size : Young Gen HeapSize (You can play with this ratio to get your desired ratio).
It is possible to increase heap size allocated by the JVM in eclipse directly
In eclipse IDE goto
Run---->Run Configurations---->Arguments
Enter -Xmx1g(It is used to set the max size like Xmx256m or Xmx1g...... m-->mb g--->gb)
java -d64 -Xms512m -Xmx4g HelloWorld
where,
-d64: Will enable 64-bit JVM
-Xms512m: Will set initial heap size as 512 MB
-Xmx4g: Will set maximum heap size as 4 GB
(here java file name is : HelloWorld.java)
Please use below command to change heap size to 6GB
export JAVA_OPTS="-Xms6144m -Xmx6144m -XX:NewSize=256m -XX:MaxNewSize=356m -XX:PermSize=256m -XX:MaxPermSize=356m"
Can I increase the heap memory to 75%
of physical memory(6GB Heap).
Yes you can. In fact, you can increase to more than the amount of physical memory, if you want to.
Whether it is a good idea to do this depends on how much else is running on your system. In particular, if the "working set" of the applications and services that are currently running significantly exceeds the available physical memory, your system is liable to "thrash", spending a lot of time moving virtual memory pages to and from disk. The net effect is that the system gets horribly slow.
Several people pointed out the specific answers for heap size with the jvm options of -Xms and -Xms. I want to point out that this is not the only type of memory options for the jvm. Specifically if you are get stack over flows, then you'll want to increase the size of the stack by adding an additional option like -Xss8m.
For this problem, the jvm options of something like -Xms2g -Xmx6g -Xss8m would be a solution.
I'm sharing this information as my google searches on how to increase jvm memory took me to this solution, and the solutions didn't work with high amounts of memory allocation. Once I figured out what the specific settings were for, I was able to google how to increase the stack size and found the missing param. :) Hope this saves others time, as it would of saved me a ton of time. :)
This only works with 64 bit version of Java. Go to Control Panel and click on the Java icon. On the small window of Java Control Panel, click on the Java menu bar and then click on view button.
If you have two Java platforms, disable the previous version of Java, then click on Runtime parameters text field and write -Xmx1024m or less than RAM size. Don't increase heap size equal to RAM otherwise your system will crash.
Yes. You Can.
You can increase your heap memory to 75% of physical memory (6 GB Heap) or higher.
Since You are using 64bit you can increase your heap size to your desired amount. In Case you are using 32bit it is limited to 4GB.
$ java -Xms512m -Xmx6144m JavaApplication
Sets you with initial heap size to 512mb and maximum heapsize to 6GB.
Hope it Helps.. :)
I have problem running the py files in my java code using eclipse/STS, getting PyException due to insufficient jvm heap memory. I have done the changes as mentioned below and I'm able to resolve this issue. Below is my System configuration.
And these are the changes I did in my workspace and voila it runs perfect now.
Here are the steps if someone wants to know how to do this in windows.

Java: what determines the maximum max heap size possible in a linux machine

I have two linux machines (both are VMs), one having 12GB memory and other having 8GB memory.
I tried to start the same java program on both machines, with maximum max heap size possible (using -Xmx flag). Following are the results I got.
12GB machine: 9460MB
8GB machine: 4790MB
If I specify a max heap size beyond above limits, I get below error.
Error occurred during initialization of VM
Could not allocate metaspace: 1073741824 bytes
I checked the free memory in two systems (using free command), and I got following.
12GB machine: approximately 3GB free.
8GB machine: approximately 4GB free.
My question is, what determines the maximum max heap size a java program can be started with, which would not result in above mentioned error? (System had sufficient memory to allocate 1073741824 bytes of memory when the program gave above error)
I have found interesting comments from JDK bug ( The bug in JDK 9 version and not in 8. It says bug was fixed in 8.x version but does not tell minor build number.
If virtual memory has been limited with "ulimit -v", and the server has a lot of RAM, then the JVM can not start without extra command line arguments to the GC.
// After "ulimit -v" The jvm does not start with default command line.
$ ulimit -S -v 4194304
$ java -version
Error occurred during initialization of VM
Could not allocate metaspace: 1073741824 bytes
Comments:
The problem seems to be that we must specify MALLOC_ARENA_MAX.
If I set the environment variable MALLOC_ARENA_MAX=4, then the jvm can start without any extra arguments.
I guess that this is not something that can be fixed from the jvm. If so we can close this bug.
When using "UseConcMarkSweepGC" then the command line above does not work.
I have tried to add MaxMetaspaceSize=128m, but it does not help.
I am sure there are an argument that makes it work, but I have not found one.
Configuring the GC with limited virtual memory is not very user friendly.
Change parameters to as per your requirement and try this one.
ulimit -S -v 4194304
java -XX:MaxHeapSize=512m -XX:InitialHeapSize=512m -XX:CompressedClassSpaceSize=64m -XX:MaxMetaspaceSize=128m -XX:+UseConcMarkSweepGC -version
The memory you have available is the combination of free RAM plus swap space. It also depends on whether the system has overcommit enabled — if so, the kernel will allow programs to allocate more memory than is actually available (within reasonable limits), since programs often allocate more than they're really going to use.
Note that overcommit is enabled by default. To disable it, write 2 into /proc/sys/vm/overcommit_memory. (Strangely, a value of 0 does not mean "no overcommit".) But it's a good idea to read the overcommit documentation first.
I did some experiments with the clues given by ravindra and found that the maximum max heap size has a direct relationship with the total virtual memory available in the system.
Total virtual memory in the system can be found (in KB) with:
ulimit-v
Total virtual memory can be altered with:
ulimit -v <new amount in KB>
The maximum max heap size possible was approximately 2GB less than the virtual memory. If you specify unlimited virtual memory using ulimit -v unlimited, You can specify any large value for the max heap size.

Is there a upper limit to how much heap size JUnits can use

My Jenkins build is running out of memory because of JUnits. When I try to give it (the JUnits) more than 4GB it errors out. I am using Linux as my build machine.
Invalid maximum heap size: -Xmx4096m
I am just wondering, is there a upper limit to how much heap size JUnits can use?
"For a 32-bit process model, the maximum virtual address size of the process is typically 4 GB, though some operating systems limit this to 2 GB or 3 GB. The maximum heap size is typically -Xmx3800m (1600m) for 2 GB limits), though the actual limitation is application dependent. For 64-bit process models, the maximum is essentially unlimited."
Found a pretty good answer here:
Java maximum memory on Windows XP
Memory is allocated to JVM not JUnit or any other class.
and there is limit on 32-bit system to assign max of 4Gb but if you requires more memory then move to 64 bit machine as there is no limit of max memory allocation .
i would guess you are using a 32 bit jvm ..
check this post:
Maximum Java heap size of a 32-bit JVM on a 64-bit OS
It's not JUnit but JVM. 4GB heap is too much for 32-bit JVMs.

Increase heap size in Java

I am working on a Windows 2003 server (64-bit) with 8 GB RAM. How can I increase the heap memory maximum? I am using the -Xmx1500m flag to increase the heap size to 1500 Mb. Can I increase the heap memory to 75% of physical memory (6 GB Heap)?
You can increase to 2GB on a 32 bit system. If you're on a 64 bit system you can go higher. No need to worry if you've chosen incorrectly, if you ask for 5g on a 32 bit system java will complain about an invalid value and quit.
As others have posted, use the cmd-line flags - e.g.
java -Xmx6g myprogram
You can get a full list (or a nearly full list, anyway) by typing java -X.
It is possible to increase heap size allocated by the JVM by using these command line options:
-Xms<size> set initial Java heap size
-Xmx<size> set maximum Java heap size
-Xss<size> set java thread stack size
In the following example, minimum heap size is set to 16mb, and the maximum to 64mb:
java -Xms16m -Xmx64m ClassName
On a 32-bit JVM, the largest heap size you can theoretically set is 4gb. To use a larger heap size, you need to use a 64-bit JVM. Try the following:
java -Xmx6144M -d64
The -d64 flag is important as this tells the JVM to run in 64-bit mode.
You can increase the Heap Size by passing JVM parameters -Xms and -Xmx like below:
For Jar Files:
java -jar -Xms4096M -Xmx6144M jarFilePath.jar
For Java Files:
java -Xms4096M -Xmx6144M ClassName
The above parameters increase the InitialHeapSize (-Xms) to 4GB (4096 MB) and MaxHeapSize(-Xmx) to 6GB (6144 MB).
But, the Young Generation Heap Size will remain same and the additional HeapSize will be added to the Old Generation Heap Size. To equalize the size of Young Gen Heap and Old Gen Heap, use -XX:NewRatio=1 -XX:-UseAdaptiveSizePolicy params.
java -jar -Xms4096M -Xmx6144M -XX:NewRatio=1 -XX:-UseAdaptiveSizePolicy pathToJarFile.jar
-XX:NewRatio = Old Gen Heap Size : Young Gen HeapSize (You can play with this ratio to get your desired ratio).
It is possible to increase heap size allocated by the JVM in eclipse directly
In eclipse IDE goto
Run---->Run Configurations---->Arguments
Enter -Xmx1g(It is used to set the max size like Xmx256m or Xmx1g...... m-->mb g--->gb)
java -d64 -Xms512m -Xmx4g HelloWorld
where,
-d64: Will enable 64-bit JVM
-Xms512m: Will set initial heap size as 512 MB
-Xmx4g: Will set maximum heap size as 4 GB
(here java file name is : HelloWorld.java)
Please use below command to change heap size to 6GB
export JAVA_OPTS="-Xms6144m -Xmx6144m -XX:NewSize=256m -XX:MaxNewSize=356m -XX:PermSize=256m -XX:MaxPermSize=356m"
Can I increase the heap memory to 75%
of physical memory(6GB Heap).
Yes you can. In fact, you can increase to more than the amount of physical memory, if you want to.
Whether it is a good idea to do this depends on how much else is running on your system. In particular, if the "working set" of the applications and services that are currently running significantly exceeds the available physical memory, your system is liable to "thrash", spending a lot of time moving virtual memory pages to and from disk. The net effect is that the system gets horribly slow.
Several people pointed out the specific answers for heap size with the jvm options of -Xms and -Xms. I want to point out that this is not the only type of memory options for the jvm. Specifically if you are get stack over flows, then you'll want to increase the size of the stack by adding an additional option like -Xss8m.
For this problem, the jvm options of something like -Xms2g -Xmx6g -Xss8m would be a solution.
I'm sharing this information as my google searches on how to increase jvm memory took me to this solution, and the solutions didn't work with high amounts of memory allocation. Once I figured out what the specific settings were for, I was able to google how to increase the stack size and found the missing param. :) Hope this saves others time, as it would of saved me a ton of time. :)
This only works with 64 bit version of Java. Go to Control Panel and click on the Java icon. On the small window of Java Control Panel, click on the Java menu bar and then click on view button.
If you have two Java platforms, disable the previous version of Java, then click on Runtime parameters text field and write -Xmx1024m or less than RAM size. Don't increase heap size equal to RAM otherwise your system will crash.
Yes. You Can.
You can increase your heap memory to 75% of physical memory (6 GB Heap) or higher.
Since You are using 64bit you can increase your heap size to your desired amount. In Case you are using 32bit it is limited to 4GB.
$ java -Xms512m -Xmx6144m JavaApplication
Sets you with initial heap size to 512mb and maximum heapsize to 6GB.
Hope it Helps.. :)
I have problem running the py files in my java code using eclipse/STS, getting PyException due to insufficient jvm heap memory. I have done the changes as mentioned below and I'm able to resolve this issue. Below is my System configuration.
And these are the changes I did in my workspace and voila it runs perfect now.
Here are the steps if someone wants to know how to do this in windows.

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