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[Solved] Initial heap size set to a larger value than the maximum heap size
In this short tutorial, I will be sharing how to solve the error «initial heap size set to a larger value than the maximum heap size». I have divided the post into two parts. In the first part, we will produce the error by passing VM/JVM parameters through the command line. In the second part, we will fix the error.
1. Producing the Error
Suppose we have below HelloWorld java program:
Compile the above HelloWorld java program in command line/terminal:
1. Run the above program by passing a single JVM parameter:
The above command will print the following output:
2. Run the HelloWorld program by passing multiple JVM parameters:
After running the above command, you will get the following output:
If the value of Xms(minimum heap size) is greater than the value of Xmx(maximum heap size) than it will produce this error as shown below:
Currently, the value of Xms(minimum heap size) is 2 gigabytes and Xmx(maximum heap size) is 1 gigabyte.
2. [Fixed] Initial heap size set to a larger value than the maximum heap size
To get rid of this error, the value of Xmx(maximum heap size) should always be greater than or equal to Xms(minimum heap size).
Run the HelloWorld program with the value of Xms(minimum heap size) set to 1 gigabyte and Xmx(maximum heap size) set to 2 gigabytes.
That’s all for today, please mention in comments in case you have any questions related to the initial heap size set to a larger value than the maximum heap size error.
Не Удалось Зарезервировать Достаточно Места Для Кучи Объектов
Узнайте о возможных причинах ошибки “Не удалось зарезервировать достаточно места для кучи объектов” и о том, как ее решить.
1. Обзор
2. Симптомы
“Не удалось зарезервировать достаточно места для кучи объектов” – это конкретная ошибка JVM, которая возникает, когда процесс Java не может создать виртуальную машину из-за ограничений памяти, возникающих в запущенной системе:
Как правило, есть два возможных сценария, когда мы сталкиваемся с ошибкой.
Во-первых, когда мы запускаем процесс Java с параметром max heap size limit ( -Xmx )
и значение больше, чем может иметь процесс в операционной системе
.
Ограничение размера кучи варьируется в зависимости от нескольких ограничений:
Во-вторых, когда процесс Java не может зарезервировать указанный объем памяти из-за других приложений, которые работают в той же системе и потребляют память.
3. Размер Кучи
Давайте посмотрим, каков максимальный размер кучи в разных средах и как мы можем установить ограничения.
3.1. Максимальный Размер Кучи
Максимальный теоретический предел кучи для 32-разрядной и 64-разрядной JVM легко определить, посмотрев на доступное пространство памяти: 2^32 (4 ГБ) для 32-разрядной JVM и 2^64 (16 экзабайт) для 64-разрядной JVM.
3.2. Как Контролировать Ограничения Размера Кучи?
У нас есть два варианта управления ограничениями размера кучи JVM.
Во-первых, используя параметры командной строки Java | при каждой инициализации JVM:
Во-вторых, используя переменную среды JAVA_OPTS для глобальной настройки параметров командной строки Java. Благодаря этому каждая инициализация JVM в системе будет автоматически использовать конфигурации, заданные в переменной среды.
Для получения дополнительной информации ознакомьтесь с нашим полным руководством по параметрам JVM.
4. Заключение
How is the default max Java heap size determined?
«the default value is chosen at runtime based on system configuration»
What system configuration settings influence the default value?
10 Answers 10
On Windows, you can use the following command to find out the defaults on the system where your applications runs.
On a Unix/Linux system, you can do
I believe the resulting output is in bytes.
maximum heap size:
UPDATE:
As pointed out by Tom Anderson in his comment, the above is for server-class machines. From Ergonomics in the 5.0 JavaTM Virtual Machine:
In the J2SE platform version 5.0 a class of machine referred to as a server-class machine has been defined as a machine with
with the exception of 32 bit platforms running a version of the Windows operating system. On all other platforms the default values are the same as the default values for version 1.4.2.
In the J2SE platform version 1.4.2 by default the following selections were made
Java 8 takes more than 1/64th of your physical memory for your Xmssize (Minimum HeapSize) and less than 1/4th of your physical memory for your -Xmxsize (Maximum HeapSize).
You can check the default Java heap size by:
In Windows:
In Linux:
What system configuration settings influence the default value?
The machine’s physical memory & Java version.
This is changed in Java 6 update 18.
Assuming that we have more than 1 GB of physical memory (quite common these days), it’s always 1/4th of your physical memory for the server vm.
As of Java 8u191 you now have the options:
that can be used to size the heap as a percentage of the usable physical RAM. (which is same as the RAM installed less what the kernel uses).
See Release Notes for Java8 u191 for more information. Note that the options are mentioned under a Docker heading but in fact they apply whether you are in Docker environment or in a traditional environment.
The default value for MaxRAMPercentage is 25%. This is extremely conservative.
My own rule: If your host is more or less dedicated to running the given java application, then you can without problems increase dramatically. If you are on Linux, only running standard daemons and have installed RAM from somewhere around 1 Gb and up then I wouldn’t hesitate to use 75% for the JVM’s heap. Again, remember that this is 75% of the RAM available, not the RAM installed. What is left is the other user land processes that may be running on the host and the other types of memory that the JVM needs (eg for stack). All together, this will typically fit nicely in the 25% that is left. Obviously, with even more installed RAM the 75% is a safer and safer bet. (I wish the JDK folks had implemented an option where you could specify a ladder)
Setting the MaxRAMPercentage option look like this:
Note that these percentage values are of ‘double’ type and therefore you must specify them with a decimal dot. You get a somewhat odd error if you use «75» instead of «75.0».
Ernesto is right. According to the link he posted [1]:
Updated Client JVM heap configuration
The default maximum heap size is half of the physical memory up to a physical memory size of 192 megabytes and otherwise one fourth of the physical memory up to a physical memory size of 1 gigabyte.
For example, if your machine has 128 megabytes of physical memory, then the maximum heap size is 64 megabytes, and greater than or equal to 1 gigabyte of physical memory results in a maximum heap size of 256 megabytes.
The Xms and Xmx are flag of Java virtual machine (JVM):
More detail
For the IBM JVM, the command is the following:
default value is chosen at runtime based on system configuration
Have a look at the documentation page
Unless the initial and maximum heap sizes are specified on the command line, they are calculated based on the amount of memory on the machine.
Client JVM Default Initial and Maximum Heap Sizes:
The default maximum heap size is half of the physical memory up to a physical memory size of 192 megabytes (MB) and otherwise one fourth of the physical memory up to a physical memory size of 1 gigabyte (GB).
Server JVM Default Initial and Maximum Heap Sizes:
On 32-bit JVMs, the default maximum heap size can be up to 1 GB if there is 4 GB or more of physical memory. On 64-bit JVMs, the default maximum heap size can be up to 32 GB if there is 128 GB or more of physical memory
What system configuration settings influence the default value?
You can specify the initial and maximum heap sizes using the flags -Xms (initial heap size) and -Xmx (maximum heap size). If you know how much heap your application needs to work well, you can set -Xms and -Xmx to the same value
Parameter Default Value
Default values of heap size parameters on 64-bit systems have been scaled up by approximately 30%. This increase is meant to compensate for the larger size of objects on a 64-bit system.
With these parameters, if the percent of free space in a generation falls below 40%, the generation will be expanded to maintain 40% free space, up to the maximum allowed size of the generation. Similarly, if the free space exceeds 70%, the generation will be contracted so that only 70% of the space is free, subject to the minimum size of the generation.
Large server applications often experience two problems with these defaults. One is slow startup, because the initial heap is small and must be resized over many major collections. A more pressing problem is that the default maximum heap size is unreasonably small for most server applications. The rules of thumb for server applications are:
In general, increase the memory as you increase the number of processors, since allocation can be parallelized.
Increase heap size in Java
13 Answers 13
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.
It is possible to increase heap size allocated by the JVM by using command line options Here we have 3 options
In the above line we can set minimum heap to 16mb and maximum heap 64mb
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:
You can increase the Heap Size by passing JVM parameters -Xms and -Xmx like below:
The above parameters increase the InitialHeapSize (-Xms) to 4GB (4096 MB) and MaxHeapSize(-Xmx) to 6GB (6144 MB).
-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
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.
Please use below command to change heap size to 6GB
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. 🙂
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.
If I specify a max heap size beyond above limits, I get below error.
I checked the free memory in two systems (using free command), and I got following.
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)
3 Answers 3
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.
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.