increase the java heap size permanently? - java

Is there a way that I can set the default heap size for the jvm on my own computer? I want to set it to 1g, because I'm always running custom programs that always hit the overage point in the default jvm size.
I just dont want to have to remember to type -XmX1g everytime I run my java app from the command line...
There has to be an admin way to do this right?

Apparently, _JAVA_OPTIONS works on Linux, too:
$ export _JAVA_OPTIONS="-Xmx1g"
$ java -jar jconsole.jar &
Picked up _JAVA_OPTIONS: -Xmx1g

For Windows users, you can add a system environment variable named _JAVA_OPTIONS, and set the heap size values there. The JVM should be able to grab the virtual machine options from _JAVA_OPTIONS.

This worked for me:
export _JAVA_OPTIONS="-Xmx1g"
It's important that you have no spaces because for me it did not work. I would suggest just copying and pasting. Then I ran:
java -XshowSettings:vm
and it will tell you:
Picked up _JAVA_OPTIONS: -Xmx1g

what platform are you running?..
if its unix, maybe adding
alias java='java -Xmx1g'
to .bashrc (or similar) work
edit: Changing XmX to Xmx

if the platform is Linux, then adding an entry in bash_profile will help.
vim ~/.bash_profile
then add
export _JAVA_OPTIONS="-Xmx4g"

Related

"Invalid maximum heap size" when running Maven

I'm having problems setting up maven. I'm using windows 7 64 bit with 4 GB of RAM.
I get this error when trying to run mvn:
Invalid maximum heap size: -Xmx512m.
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.
Here are my user variables:
JAVA_HOME=C:\Program Files\Java\jdk1.7.0_55
M2=%M2_HOME%\bin
M2_HOME=C:\Program Files\Apache Software Foundation\apache-maven-3.2.1
MAVEN_OPTS=-Xms256m -Xmx512m
Path=%M2%;%JAVA_HOME%\bin
User #med_alpa had the right suggestion in my case (Windows):
I resolved the same issue on windows executing this command on windows
command line : set MAVEN_OPTS=-Xmx1024M -XX:MaxPermSize=256M
So make sure to not put quotes around the value you set for MAVEN_OPTS
alter jvm.config in .mvn directory ( it is in controller directory ).
study mvn.sh that comes with maven. you will see MAVEN_OPTS setting in the script.
try out java -version before altering.
eg : java -Xmx512m -version
now you know how to go about and make the changes.
/sunil
Try using: -Xmx1024M
Note: 'M' instead 'm'
On MacOS a version of #adriaan-koster's answer works.
In your ~/.zshrc (or .bashrc or .bash_profile) config file add this line:
export MAVEN_OPTS="-Xmx2G"
To test, run mvn -v again and verify that it prints the Maven version, Maven home location, and Java version.

How to set permanent memory settings for java?

I use jre-7u40-linux-x64 on SL6.4.
Server with more than 30Gb of RAM. User's memory limits sets to several gigabytes, but
command java returns error.
"Not enough memory heap..."
Under root it's ok and -XshowSettings:vm shows that memory size is automaticaly estimated.
Under user with options -Xmx256m it's ok also.
So is it possible to set the property(-Xmx256m) permanently?
I tried environtment variables (JAVA_OPTS,JAVA_OPTIONS) and jvm.cfg. With no results.
Any advices and keywords?
Thank you.
JAVA_OPTS / JAVA_OPTIONS do not help: Running java with JAVA_OPTS env variable
However, if you want such feature, you can create a simple shell script.
A script called java in a location that is in user's PATH environment variable before the actual java binary should do the trick:
#!/bin/bash
/usr/local/java/oracle/bin/java "$JAVA_OPTS" "$#"

How do I properly set the permgen size?

I have this VM with tomcat, java, and grails in it. I've been getting permgen errors so I looked around and found the solution:
set JAVA_OPTS="-Xms256m -Xmx1024m -XX:PermSize=512m -XX:MaxPermSize=512m"
I use SSH to access the vm and type the arguments above. I suppose that would fix the problem. Thing is, I wanted to make sure that I did it correctly. So I searched again on how I could check the current permSize and this is the solution I got:
jinfo -flag MaxPermSize 6444
6444 is the pid, and as a response, I got this.
-XX:MaxPermSize=85983232
Question: Is the value of the maxPermSize in bytes? because, if it is, then that would mean that the java_opts command didn't work. I am expecting to get 512m but 85983232 bytes = 82 mb.. Or am I seeing it wrong..? Can anybody enlighten me on this? D:
You have to change the values in the CATALINA_OPTS option defined in the Tomcat Catalina start file. To increase the PermGen memory change the value of the MaxPermSize variable, otherwise change the value of the Xmx variable.
Linux & Mac OS: Open or create setenv.sh file placed in the "bin" directory. You have to apply the changes to this line:
export CATALINA_OPTS="$CATALINA_OPTS -server -Xms256m -Xmx1024m -XX:PermSize=512m -XX:MaxPermSize=512m"
Windows:
Open or create the setenv.bat file placed in the "bin" directory:
set CATALINA_OPTS=-server -Xms256m -Xmx1024m -XX:PermSize=512m -XX:MaxPermSize=512m
Don't put the environment configuration in catalina.bat/catalina.sh. Instead you should create a new file in CATALINA_BASE\bin\setenv.bat to keep your customizations separate of tomcat installation.
So you are doing the right thing concerning "-XX:MaxPermSize=512m": it is indeed the correct syntax. You could try to set these options directly to the Catalyna server files so they are used on server start.
Maybe this post will help you!
How to make sure that Tomcat6 reads CATALINA_OPTS on Windows?
Completely removed from java 8 +
Partially removed from java 7 (interned Strings for example)
source

Increase heap size in java for weka

I'm trying to increase the heap size in java for weka which keeps crashing. I used the suggested line:
> java -Xmx500m -classpath
but I get the following error:
-classpath requires class path specification
I'm not sure what this means. Any suggestions?
What I found was the actual issue was in the file 'RunWeka.ini' in '\Program Files (x86)\Weka-3-6'. I opened it with notepad and in the middle of the file there is a line 'maxheap = 512m'.
I changed the line to read 'maxheap=2000m', saved the file and reloaded weka and this fixed my problems.
I'm not sure if this is the correct way to do it or not but it worked for me.
Run this command in your terminal:
java -Xmx1024m -jar weka.jar
Omit the -classpath option. Use just -Xmx500m option.
So, instead of just:
java weka.core.Instances data/soybean.arff
you do:
java -Xmx500m weka.core.Instances data/soybean.arff
If you run weka via some script (RunWeka.bat for example), then you need to modify that script (with some text editor like notepad).
If you're using Weka 3.8.1 on Windows you can save yourself a lot of trouble by editing the javaOpts parameter. The parameter maxheap isn't used anymore, so you can set javaOpts like this in RunWeka.ini file:
javaOpts= -Xmx1040m
Where 1040m is the amount of memory you want to allocate.
Mind that the file is case sensitive.
There are a lot of ways to set this up, but this is the faster way to get Weka runing on a Windows environment at this version.
Edit: If you want Weka to use more than 1gb on windows, you need to have JDK installed. Regular JRE wont do it.
The official Weka answer (for all operating systems and Weka versions) can be found on http://weka.wikispaces.com/OutOfMemoryException.
In case you are using a recent Weka version on Windows, the answer is:
Modify the maxheap parameter in the RunWeka.ini file.
On Ubuntu i had the same problem
but i solve it by increasing the amount of memory to use for the Java Virtual Machine
run this : weka -m 1024m
You need to specify a classpath after -classpath, similar to the PATH env variable you need to specify the path where Java can find the classes.
The -Xmx500m setting looks fine, except that I would suggest to use 512m.
For Mac OS, you have to edit a configuration file in order to increase the heap size of the Weka UI application.
I am repeating what I wrote in: Is there a workaround to solve "Java heap space" memory error when the max heap value has been already specified?
Quit out of Weka if it is running.
cd into /Applications/weka-XXX.app/Contents , or wherever your weka executable was installed. There will be a file called Info.plist there. It is an XML text file. I suggest you save a copy of it to another location, as you'll need to edit it in the next step.
Open the Info.plist (XML) file in your favorite text editor and look for a block that says "VMOptions". There should be a value that says "-Xmx256M" or something similar that specifies the maximum heap size. You should change that value to something bigger, such as "-Xmx1024M".
Start Weka.
I am running Weka 3.6 in windows. This is what i did.
Go to the Weka installation directory and you will find a RunWeka.bat file. Open this file in a text editor and add -Xmx argument in the java command line.
for instance this sets to 4GB memory,
%_java% -Xmx4096m -classpath . RunWeka -i .\RunWeka.ini -w .\weka.jar -c %_cmd% "%2"
The official Weka answer is right..But....crucial is to first get rid of all JVM files and install the relevant 32 or 64 bit Java version. Not using the relevant version causes many problems including the impossibility to increase the heap further than 1024m (by changing the ini file).
Weka 3.9.2 also does not has the option of maxheap anymore. RunWeka.ini have the option of javaOpts, So you may change the below to your required memory allocation,
javaOpts=%JAVA_OPTS% ---- > javaOpts= -Xmx1024m
Here 1024m is the customised amount of memory you want to allocate.
The best way to do it using this command
java -Xmx1024m -[weka classifier] -t [training file path]
The answers above are too old (last one is 1 year ago).
I had same issue with my WEKA (version 3.8.1) on Windows 10.
I had a problem to update the heap size , the way I fixed it is by adding an environment variable (under control panel) as follows:
JAVA_OPTS = -Xms30000m -Xmx30000m
Tip: Just ensure that RunWeka.ini is using this environment variable.
In the above example I give WEKA 30GB. It works.
Hope it will be helpful for some people.
You should also see if default thread stack size 20MB is enough. Increase the value to 50MB in the file /Applications/weka-3-8-1-oracle-jvm.app/Contents/Info.plist (on MAC) like below:
<string>-Xss50M</string>
If we are using Weka Workbench CLI or Knowledge explorer we need to
change as below.
As the documentation suggests the runtime parameter should be -Xmx[size_required]m where [size_required] is memory size you intend to keep to avoid memory exception.
Open RunWeka.ini
Define maxheap=[size_required]G
In my case I kept maxheap=4G , One can set like maxheap=4096m and add -Xmx#maxheap# to all the run options at # setups (prefixed with "cmd_") sections next to java commands
like below
cmd_default=javaw -Xmx#maxheap# ...............
cmd_console=cmd.exe /K start cmd.exe ..................
cmd_explorer=java -Xmx#maxheap# .................
cmd_knowledgeFlow=java -Xmx#maxheap#....................
maxheap=4G
Verify the same by restarting Weka and Help>>SystemInfo
If you run weka from the command line but not through java i.e. typing weka into the command line, instead of typing
weka
specify the memory flag
weka -m 1024m
This will specify 1024 megabytes.
If you're running weka via weka.sh, you can directly run it with memory option.
For example,
sh weka.sh -memory 10g
This will increase the heap size to 10Gb (tested using Weka 3.8.4 on Ubuntu 18.04)

How to increase Java heap space for a tomcat app

There are lots of questions that ask this or a similar question.
They all give the command that has to be executed, what I don't understand is where do I write this command. I want to permanently increase the heap space for my tomcat apps.
I read this page http://javahowto.blogspot.com/2006/06/6-common-errors-in-setting-java-heap.html and it says under the Tomcat section
Stop Tomcat server, set environment variable CATALINA_OPTS, and then restart Tomcat. Look at the file tomcat-install/bin/catalina.sh or catalina.bat for how this variable is used. For example,
set CATALINA_OPTS=-Xms512m -Xmx512m (Windows, no "" around the value)
export CATALINA_OPTS="-Xms512m -Xmx512m" (ksh/bash, "" around the value)
setenv CATALINA_OPTS "-Xms512m -Xmx512m" (tcsh/csh, "" around the value)
So I replaced the line
set CATALINA_OPTS=
with
set CATALINA_OPTS=-Xms512m -Xmx512m
But I still get the error.
javax.servlet.ServletException: Servlet execution threw an exception
root cause
java.lang.OutOfMemoryError: Java heap space
java.lang.reflect.Array.multiNewArray(Native Method)
java.lang.reflect.Array.newInstance(Array.java:90)
nom.tam.util.ArrayFuncs.newInstance(ArrayFuncs.java:1028)
nom.tam.fits.ImageData.read(ImageData.java:259)
nom.tam.fits.Fits.readHDU(Fits.java:573)
controller.UploadServlet.retreiveFITSFileFields(UploadServlet.java:206)
controller.ScanServerFiles.doPost(ScanServerFiles.java:39)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
There is a mechanism to do it without modifying any files that are in the distribution. You can create a separate file %CATALINA_HOME%\bin\setenv.bat or $CATALINA_HOME/bin/setenv.sh and put your environment variables there. Further, the memory settings apply to the JVM, not Tomcat, so I'd set the JAVA_OPTS variable instead:
set JAVA_OPTS=-Xmx512m
First of all you cannot change the memory settings only for a tomcat application but rather for all tomcat instance.
If you are running tomcat from console (using startup.bat) you'll need to edit catalina.bat and play around with CATALINA_OPTS. For example:
set CATALINA_OPTS=-Xms512m -Xmx512m
Restarting tomcat will apply the new settings.
If you are still getting OutOfMemoryError you need to know how much memory does your application need at that particular moment (nom.tam.util.ArrayFuncs...). You'll either have to optimize the application or simply increase the memory provided to tomcat.
Your change may well be working. Does your application need a lot of memory - the stack trace shows some Image related features.
I'm guessing that the error either happens right away, with a large file, or happens later after several requests.
If the error happens right away, then you can increase memory still further, or investigate find out why so much memory is needed for one file.
If the error happens after several requests, then you could have a memory leak - where objects are not being reclaimed by the garbage collector. Using a tool like JProfiler
can help you monitor how much memory is being used by your VM and can help you see what is using that memory and why objects are not being reclaimed by the garbage collector.
Open the server tab in eclipse
right click open
click on open lauch configuration
Go to arguments
Here you can add in VM arguments after endorsed
-Xms64m -Xmx256m
You need to add the following lines in your catalina.sh file.
export CATALINA_OPTS="-Xms512M -Xmx1024M"
UPDATE : catalina.sh content clearly says -
Do not set the variables in this script. Instead put them into a script setenv.sh in CATALINA_BASE/bin to keep your customizations separate.
So you can add above in setenv.sh instead (create a file if it does not exist).
Easiest way of doing is: (In Linux/Ububuntu e.t.c)
Go to tomcat bin directory:
cd /opt/tomcat8.5/bin
create new file under bin directory "setenv.sh" and save below mention entries in it.
export CATALINA_OPTS="$CATALINA_OPTS -Xms512m"
export CATALINA_OPTS="$CATALINA_OPTS -Xmx2048m"
export CATALINA_OPTS="$CATALINA_OPTS -XX:MaxPermSize=256m"
and issue command:
./catalina.sh run
In your catalina log file you can see entry like this:
INFO [main] VersionLoggerListener.log Command line argument: -Xms512m
INFO [main] VersionLoggerListener.log Command line argument: -Xmx2048m
INFO [main] VersionLoggerListener.log Command line argument: -XX:MaxPermSize=256m
Which confirms that above changes took place.
Also, the value of "Xms512m" and "-Xmx2048m" can be modified accordingly in the setenv.sh file.
Startup of tomcat could be done in two steps as well.
cd /opt/tomcat8.5/bin
Step #1
run ./setenv.sh
Step #2
./startup.sh
If you're using systemd edit:
/usr/lib/systemd/system/tomcat8.service
and set
Environment=CATALINA_OPTS="-Xms512M -Xmx2048M -XX:MaxPermSize=256m"
if you are using Windows, it's very simple. Just go to System Environnement variables (right-clic Computer > Properties > Advanced System Parameters > Environnement Variables); create a new system variable with name = CATALINA_OPTS and value = -Xms512m -Xmx1024m. restart Tomcat and enjoy!
For Windows Service, you need to run tomcat9w.exe (or 6w/7w/8w) depending on your version of tomcat.
First, make sure tomcat is stopped. Then double click on tomcat9w.exe. Navigate to the Java tab. If you know you have 64 bit Windows with 64 bit Java and 64 bit Tomcat, then feel free to set the memory higher than 512. You'll need to do some task manager monitoring to determine how high to set it. For most apps developed in 2019... I'd recommend an initial memory pool of 1024, and the maximum memory pool of 2048. Of course if your computer has tons of RAM... feel free to go as high as you want.
Also, see this answer: How to increase Maximum Memory Pool Size? Apache Tomcat 9
you can set this in catalina.sh as CATALINA_OPTS=-Xms512m -Xmx512m
Open your tomcat-dir/bin/catalina.sh file and add following line anywhere -
CATALINA_OPTS="$CATALINA_OPTS -Xms1024m -Xmx3024m"
and restart your tomcat
Just set this extra line in catalina.bat file
LINE NO AROUND: 143
set "CATALINA_OPTS=-Xms512m -Xmx512m"
And restart Tomcat service

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