In a shell script, I have set the JAVA_OPTS environment variable (to enable remote debugging and increase memory), and then I execute the jar file as follows:
export JAVA_OPTS="-Xdebug -Xrunjdwp:transport=dt_socket,address=8001,server=y,suspend=n -Xms512m -Xmx512m"
java -jar analyse.jar $*
But it seems there is no effect of the JAVA_OPTS env variable as I cannot connect to remote-debugging and I see no change in memory for the JVM.
What could be the problem?
PS: I cannot use those settings in the java -jar analyse.jar $* command because I process command line arguments in the application.
You can setup _JAVA_OPTIONS instead of JAVA_OPTS. This should work without $_JAVA_OPTIONS.
I don't know of any JVM that actually checks the JAVA_OPTS environment variable. Usually this is used in scripts which launch the JVM and they usually just add it to the java command-line.
The key thing to understand here is that arguments to java that come before the -jar analyse.jar bit will only affect the JVM and won't be passed along to your program. So, modifying the java line in your script to:
java $JAVA_OPTS -jar analyse.jar $*
Should "just work".
In the past 12 years some changes were made.
Environment variable JAVA_OPTS was and is NOT a standardized option. It is evaluated by some shell script wrappers for Java based tools, an example of how this works is in the answer from ZoogieZork.
The environment variable _JAVA_OPTIONS mentioned by HEX is nowadays deprecated/undocumented.
Starting with Java 9, the recommended way to do what you wanted is the variable JDK_JAVA_OPTIONS, see Using the JDK_JAVA_OPTIONS Launcher Environment Variable in the Oracle Java 9 documentation, and this comprehensive answer What is the difference between JDK_JAVA_OPTIONS and JAVA_TOOL_OPTIONS when using Java 11?.
Related
I am new to lua script features.
I tried using,
os.execute("export MY_VAR=10")
io.popen("export MY_VAR=10")
from lua script.
I try reading MY_VAR variable from shell using echo $MY_VAR after lua script is executed but I do not see MY_VAR getting set to 10.
How do we set the environment variable using lua script?
Your problem isn't a lua problem. Your problem is misunderstanding how process environments work.
Every time you run os.execute or io.popen you are running a new process with new environment.
So while you may be correctly setting MY_VAR in that processes environment (and it would affect any processes run as children processes of that process) it doesn't survive beyond the death of the launched process and so cannot be seen by any other processes.
If you want to affect the lua process's environment (which would then, in turn, affect the environment's of processes run by lua) then you need a binding to the setenv system function (which lua itself doesn't provide as it doesn't pass the clean C test that lua uses for things it includes).
I've tried java -jar shell.jar < commands.txt but that doesn't seem to work.
One would think a shell would support redirection for use in scripts.
There's a --spring.shell.commandFile option that's supported at the Shell app, but it is not documented - we will fix it.
With that, you could pass the commands like:
java -jar shell.jar --spring.shell.commandFile="commands.txt"
I have set
ANT_HOME as C:\Janice\GuideWire\AllSoftwares\apache-ant-1.7.1 (User variables)
And
PATH=%ANT_HOME%\bin (system variables)
It just does not work. I get ANT_HOME incorrectly set or cannot be located.
I also tried:
ANT_HOME as C:\Janice\GuideWire\AllSoftwares\apache-ant-1.7.1 (User variables)
And
PATH=%ANT_HOME%\bin (User variables)
I tried re starting the system for both the cases. Nothing works. plz help
I have got variables in system variables section and it's working...
After modification plesae execute:
Restart OS
Type in command line set and check if ANT_HOME/ant configuration is present
Type ant -v
If C:\Janice\GuideWire\AllSoftwares\apache-ant-1.7.1\bin is set in the path, then that should work. Make sure this parameter is separated by a semi-colon(;) in path.
set path=C:\Janice\GuideWire\AllSoftwares\apache-ant-1.7.1\bin;%path%
Or you may try adding double slash once.
You also need to have Java installed and present on path.
Run cmd and there:
set | findstr ANT
set | findstr JAVA
and
echo %PATH% | findstr jdk
each of those commands need to return something.
Verify your java config by running:
java -version
where java
result should be as follows
c:\Guidewire\TrainingApp\bin>java -version
java version "1.6.0_45"
Java(TM) SE Runtime Environment (build 1.6.0_45-b06)
Java HotSpot(TM) 64-Bit Server VM (build 20.45-b01, mixed mode)
c:\Guidewire\TrainingApp\bin>where java
C:\Windows\System32\java.exe
c:\tools\jdk1.6.0_21\bin\java.exe
if it's not, then probably you need to set up Java first
Make sure that your ANT_HOME variable is
I'm running play2 on a 512M vps.
It can create a new app:
play new test
But can't start that test project:
cd test
play
It reports such an error:
[freewind#289144 test]$ play
Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.
[freewind#289144 test]$
After some research, I found play2 will invoke play-2.0/framework/build, and build has following settings:
I tried to modify the play-2.0/play shell, from:
java ${DEBUG_PARAM} -Xms512M -Xmx1536M -Xss1M -XX:+CMSClassUnloadingEnabled
-XX:MaxPermSize=384M -Dfile.encoding=UTF8 -Dplay.version="${PLAY_VERSION}"
-Dsbt.ivy.home=`dirname $0`/../repository -Dplay.home=`dirname $0`
-Dsbt.boot.properties=`dirname $0`/sbt/sbt.boot.properties
-jar `dirname $0`/sbt/sbt-launch.jar "$#"
We can see that the Xms is 512M, the vps hasn't enough memory for it.
So I change it to:
java ${DEBUG_PARAM} -Xms112M -Xmx300M -Xss1M
-XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=84M -Dfile.encoding=UTF8
...
This time, the error message is changed:
Error occurred during initialization of VM
Cannot create VM thread. Out of system resources.
What should I do?
Assuming you're running the Sun Hotspot VM, run it like this:
_JAVA_OPTIONS="-Xmx384m" play <your commands>
And you'll get what you need. When the VM launches, it includes the contents of the _JAVA_OPTIONS environment variable along with any other command-line Java options you specify. You'll know it was picked up because you'll see the following message on your console:
Picked up _JAVA_OPTIONS: -Xmx384m
The shell command above defines the variable only for execution of the rest of the shell command. If you wanted to make it more durable, you could say something like
export _JAVA_OPTIONS="-Xmx384m"
and put that in .bash_profile, or .profile, etc.
The _JAVA_OPTIONS environment variable is poorly documented, and I'm not sure how widely it is supported, but I'm pretty sure it works on Linux, BSD* (like Mac OS), and...I don't know what else.
I faced the same issue but I found the reason and the solution.
It is a java parameter in play. I do a simple check:
java -Xms512M -Xmx1024M -Xss1M -XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=256M -version
This does not work, but
java -Xms512M -Xmx1024M -Xss1M -XX:+CMSClassUnloadingEnabled
does work! and
java -Xms512M -Xmx512M -Xss1M -XX:+CMSClassUnloadingEnabled -XX:MaxPermSize=256M
works too.
You have to modify the build.bat as I did: on maximum mem size or change the maximum permanent size.
I build and develop locally. I then run "play dist" to create a distribution which contains a start script. I deploy to my 512MB VPS using Fabric and do not have any memory issues.
Another way is to use the following command (it works when you dont use play dist but have the framework installed on the server aswell, maybe it works with the standalone package too but I have not tested it):
play "start 6000" -Xms64m -Xmx128m -server
the "start 6000" will start the server listening on port 6000.
play stage && target/start -Xmx384m
I have Installshiled script which define CATALINA_HOME as environment Variable initially. same script after that execute the batch file service.bat that is using CATALINA_HOME. this file when executed display the error CATALINA_HOME is not define define correctly. as this variable is defined as environmental VARIABLE and pointing Tomcat Directory Properly. I thing the system require reboot to recognize environment Variables.Is there any way to define Environment that work directly without reboot. I am using 64 bit Windows 7.
I may be wrong but the script that you're running loads the env variables once when you start it so you won't get any new env variables added during the runtime of the script.
And in your script, if you just execute the batch file, it will use the same out dated env variables the script started with.
What I do is run 'cmd /k service.bat' This starts a new shell (with the updated env variables) and runs the batch file and terminates afterwards.
You shouldn't need to reboot between your install.